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  • 1.
    Andersson, Sören
    et al.
    Örebro universitet, Institutionen för medicinska vetenskaper. Folkhälsomyndigheten, Public Health Agency of Sweden.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    CHIMERIC MOMP ANTIGEN2015Patent (Övrig (populärvetenskap, debatt, mm))
  • 2.
    Andersson, Sören
    et al.
    Örebro universitet, Institutionen för medicinska vetenskaper. Folkhälsomyndigheten, Public Health Agency of Sweden.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Chimeric MOMP antigen2014Patent (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    The present invention regards polypeptides capable of eliciting an immunological response that is protective against Chlamydia trachomatis. The polypeptide comprises a first amino acid sequence which has at least 90% homology with the amino acid sequence according to SEQ ID NO: 1 and a second amino acid sequence which has at least 90% homology with the amino acid sequence according to SEQ ID NO: 2. Furthermore, production of these polypeptides and pharmaceutical compositions comprising them are also provided.

  • 3. Brosché, Mikael
    et al.
    Gittins, John R.
    Sävenstrand, Helena
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Gene expression under environmental stresses: molecular marker analysis2002Ingår i: Molecular techniques in crop improvement / [ed] S. Mohan Jain, D.S. Brar, B.S. Ahloowalia, Boston: Kluwer Academic Publishers, 2002, s. 371-408Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 4. Brosché, Mikael
    et al.
    Schuler, Mary A.
    Kalbina, Irina
    Örebro universitet, Institutionen för naturvetenskap.
    Connor, Lynn
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Gene regulation by low level UV-B radiation: identification by DNA array analysis2002Ingår i: Photochemical and Photobiological Sciences, ISSN 1474-905X, E-ISSN 1474-9092, Vol. 1, nr 9, s. 656-664Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    UV-B radiation alters transcript levels of various defence genes and photosynthetic genes in plants. Utilising a DNA array with 5000 ESTs and cDNAs from Arabidopsis thaliana, 70 genes were found to show a greater than two-fold induction or repression of transcript levels. Six genes (MEB5.2, PyroA, Ubq3, Lhcb6, F5D21.10 and the gene for an RNA polymerase II subunit) were tested for stress specific gene regulation on northern blots with RNA from plants exposed to low dose UV-B radiation, ozone or wounding. Transcript levels for PyroA, Uhq3 and the gene for a RNA polymerase II subunit were all specifically increased by UV-B. MEB5.2 mRNA levels also rose, whereas Lhcb6 and FSD21.10 transcript levels decreased under all stresses. The PyroA gene product in fungi is needed for biosynthesis of pyridoxine, and might have a role in protection against singlet oxygen. The Ubq3 gene encodes the ubiquitin protein that is attached to proteins destined for degradation. MEB5.2 and F5D21.10 represent novel gene products whose function have not yet been identified. Pairwise comparisons between the UV-B inducible promoters have identified a series of elements present in the MEB5.2 and PyroA promoters, absent from promoters of genes for early phenylpropanoid metabolism and that may be responsible for modulating their UV-B responses.

  • 5. Brosché, Mikael
    et al.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Molecular events following perception of ultraviolet-B radiation by plants2003Ingår i: Physiologia Plantarum: An International Journal for Plant Biology, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 117, nr 1, s. 1-10Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Exposure of plants to UV-B radiation (280–320 nm) results in changes in expression of a large number of genes. Before UV-B radiation or light of other wavelengths can give rise to a cellular response, it has to be perceived by some kind of receptor, and the information transduced via a signalling pathway to the target molecules, be it proteins in the cytoplasm

    or the genetic material in the nucleus. The perception of low levels of UV-B probably occurs via a UV-B photoreceptor followed by several different signalling pathways. These pathways include second messengers such as calcium, kinases and the catalytic formation of reactive oxygen species. High levels of UV-B, on the other hand, probably cause cellular damage

    and oxidative stress, thus activating a general stress signal transduction pathway which leads to a response similar to that which occurs after pathogen attack and other stresses. Some of the genes identified so far as being regulated by UV-B encode proteins involved in the biosynthesis of protective pigments, DNA repair and antioxidative enzymes, photosynthetic genes, cell cycle genes, and stress genes induced by other types of stimuli (i.e. pathogenesis-related proteins and senescence-induced genes). In the light of the information obtained on components necessary for UV-B-induced changes in gene expression, we propose in this mini-review a working model for UV-B perception and signal transduction. This model also takes into account dosage differences for the observations, which imply a separation into UV-B-specific and more general stress signal transduction.

  • 6.
    Comont, David
    et al.
    Aberystwyth University, Aberystwyth, UK.
    Albert, Andreas
    Helmholtz Zentrum, München, Germany.
    Aphalo, Pedro
    Helsingfors universitet, Helsingfors, Finland.
    Gabersick, Alenka
    University of Ljubljana, Ljubljana, Slovenia.
    Hauser, Marie Teres
    University of Natural Resources and Life Sciences, Vienna, Austria.
    Jansen, Marcel
    University College of Cork, Cork, Ireland.
    Robson, Matthew
    Helsingfors universitet, Helsingfors, Finland.
    Schreiner, Monika
    Leibniz-Institute of Vegetable and Ornamental Plants, Großbeeren, Germany.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Gwynn-Jones, Dylan
    Aberystwyth University, Aberystwyth, UK.
    Exploring latitudinal variation in UV radiation and climate: impacts on a model grass system2011Ingår i: Abstracts of the 1st Annual Meeting of COST Action FA0906 UV4growth, Szeged: Biological Research Center of the Hungarian Academy of Sciences , 2011, s. 14-14Konferensbidrag (Refereegranskat)
    Abstract [en]

    Perennial ryegrass (Lolium perenne) seedlings were grown at 14 European locations across a latitudinal gradient spanning 37 to 68°N. Seedlings planted in nutrient enriched vermiculite were grown outdoors over five weeks between the 29th June and the 3rd August 2010. At each location there were three treatments – open, filtered with cellulose acetate (UV transparent) and filtered with Mylar (UV opaque). Plants were regularly watered and outdoor climatic conditions were monitored at nearby meteorological stations. The aim of the experiment was to assess the significance of ambient UV radiation to L.perenne, both at each location and across the gradient in terms of aboveground biomass, tiller number, and the level of UV protective plant pigments. Material was further screened using metabolite fingerprinting (FT-IR spectroscopy) to assess local, regional and latitudinal variation in total plant chemistry. Data presented will explore and interpret the complex variations in growth and chemistry looking at local responses and the latitudinal gradient explored.

  • 7.
    Comont, David
    et al.
    Aberystwyth University, Aberystwyth, UK.
    Martinez Abaigar, Javier
    University of La Rioja, Logroño, Spain.
    Albert, Andreas
    Helmholtz Zentrum, München, Germany.
    Aphalo, Pedro
    Helsingfors universitet, Helsingfors, Finland.
    Causton, David R
    Aberystwyth University, Aberystwyth, UK.
    López Figueroa, Félix
    University of Málaga, Málaga, Spain.
    Gaberscik, Alenka
    University of Ljubljana, Ljubljana, Slovenia.
    Llorens, Laura
    University of Girona, Girona, Spain.
    Hauser, Marie-Theres
    University of Natural Resulrces and Life Sciences-BOKU, Wien, Austria.
    Jansen, Marcel A K
    University College Cork, Cork, Ireland.
    Kardefelt, Majlis
    Abisko forskningsstation, Abisko, Sweden.
    de la Coba Luque, Paqui
    University of Málaga, Málaga, Spain.
    Neubert, Susanne
    University of Natural Resulrces and Life Sciences-BOKU, Wien, Austria.
    Núnez-Olivera, Encarnación
    University of La Rioja, Logroño, Spain.
    Olsen, Jorunn
    Norwegian University of Life Sciences, Ås, Norway.
    Robson, Matthew
    Helsingfors universitet, Helsingfors, Finland.
    Schreiner, Monika
    Leibniz-Institute of Vegetable and Ornamental Crops, Großbeeren, Germany.
    Sommaruga, Ruben
    University of Innsbruck, Innsbruck, Austria.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Torre, Sissel
    Norwegian University of Life Sciences, Ås, Norway.
    Turunen, Minna
    University of Lapland, Rovaniemi, Finland.
    Veljovic-Jovanovic, Sonja
    Institute for Multidisciplinary Research, Belgrade, Serbia.
    Verdaguer, Dolors
    University of Girona, Girona, Spain.
    Vidovic, Marija
    Institute for Multidisciplinary Research, Belgrade, Serbia.
    Wagner, Johanna
    University of Innsbruck, Innsbruck, Austria.
    Winkler, Jana Barbro
    Helmholtz Zentrum, München, Germany.
    Zipoli, Gaetano
    C.N.R. Ibimet, Firenze, Italy.
    Gwynn-Jones, Dylan
    University of Aberystwyth, Aberystwyth, UK.
    UV responses of Lolium perenne raised along a latitudinal gradient across Europe: a filtration study2012Ingår i: Physiologia Plantarum: An International Journal for Plant Biology, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 145, s. 604-618Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lolium perenne (cv. AberDart) was grown at 14 locations along a latitudinal gradient across Europe (37–68◦N) to study the impact of ultraviolet radiation (UV) and climate on aboveground growth and foliar UV-B absorbing compounds. At each location, plants were grown outdoors for 5 weeks in a replicated UV-B filtration experiment consisting of open, UV-B transparent (cellulose diacetate) and UV-B opaque (polyester) environments. Fourier transform-infrared spectroscopy was used to compare plantmetabolite profiles in relation to treatment and location. UV radiation and climatic parameters were determined for each location from online sources and the data were assessed using a combination of ANOVA and multiple regression analyses. Most of the variation in growth between the locations was attributable to the combination of climatic parameters, with minimum temperature identified as an important growth constraint. However, no single environmental parameter could consistently account for the variability in plant growth. Concentrations of foliar UV-B absorbing compounds showed a positive trend with solar UV across the latitudinal gradient; however, this relationship was not consistent in all treatments. The most striking experimental outcome from this study was the effect of presence or absence of filtration frames onUV-absorbing compounds. Overall, the study demonstrates the value of an European approach in studying the impacts of natural UV across a large latitudinal gradient. We have shown the feasibility of coordinated UV filtration at multiple sites but have also highlighted the need for open controls and careful interpretation of plant responses.

  • 8.
    Czégény, Gyula
    et al.
    Department of Plant Biology, University of Pécs, Pécs, Hungary.
    Körösi, Laszlo
    Research institute for Viticulture and Oenology, University of Pécs, Pécs, Hungary.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Hideg, Éva
    Department of Plant Biology, University of Pécs, Pécs, Hungary.
    Multiple roles for Vitamin B6in plant acclimation to UV-B2019Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, nr 1, artikel-id 1259Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Direct and indirect roles of vitamin B6in leaf acclimation to supplementary UV-B radiation are shown in vitamin B6deficient Arabidopsis thalianamutant rsr4-1 and C24 wild type. Responses to 4 days of 3.9 kJ m-2d-1 biologically effective UV-B dose were compared in terms of leaf photochemistry, vitamer content, and antioxidant enzyme activities; complemented with a comprehensive study of vitamer ROS scavenging capacities. Under UV-B, rsr4-1 leaves lost more (34%) photochemical yield than C24 plants (24%). In the absence of UV-B, rsr4-1 leaves contained markedly less pyridoxal-5’-phosphate (PLP) than C24 ones, but levels increased up to the C24 contents in response to UV-B. Activities of class-III ascorbate and glutathione peroxidases increased in C24 leaves upon the UV-B treatment but not in the rsr4-1 mutant. SOD activities remained the same in C24 but decreased by more than 50% in rsr4-1 under UV-B. Although PLP was shown to be an excellent antioxidant in vitro, our results suggest that the UV-B protective role of B6 vitamers is realized indirectly, via supporting peroxidase defence rather than by direct ROS scavenging. We hypothesize that the two defence pathways are linked through the PLP-dependent biosynthesis of cystein and heme, affecting peroxidases.

  • 9.
    Czégény, Gyula
    et al.
    Institute of Biology, University of Pécs, Pécs, Hungary; Institute of Plant Biology, Biological Research Centre, Szeged, Hungary.
    Wu, Min
    Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden.
    Dér, András
    Institute of Biophysics, Biological Research Centre, Szeged, Hungary.
    Eriksson, Leif A
    Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Hideg, Éva
    Institute of Biology, University of Pécs, Pécs, Hungary.
    Hydrogen peroxide contributes to the ultraviolet-B (280-315 nm) induced oxidative stress of plant leaves through multiple pathways2014Ingår i: FEBS Letters, ISSN 0014-5793, E-ISSN 1873-3468, Vol. 588, nr 14, s. 2255-2261Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Solar UV-B (280-315 nm) radiation is a developmental signal in plants but may also cause oxidative stress when combined with other environmental factors. Using computer modelling and in solution experiments we show that UV-B is capable of photosensitizing hydroxyl radical production from hydrogen peroxide. We present evidence that the oxidative effect of UV-B in leaves is at least two-fold: (i) it increases cellular hydrogen peroxide concentrations, to a larger extent in pyridoxine antioxidant mutant pdx1.3-1 Arabidopsis and (ii) is capable of a partial photo-conversion of both ‘natural’ and ‘extra’ hydrogen peroxide to hydroxyl radicals. As stress conditions other than UV can increase cellular hydrogen peroxide levels, synergistic deleterious effects of various stresses may be expected already under ambient solar UV-B.

  • 10. dos Santos, Daniel
    et al.
    Scherbak, Nikolai
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Eriksson, Leif A.
    Örebro universitet, Institutionen för naturvetenskap.
    Modelling Pisum sativum short-chain dehydrogenase/reductase enzymesManuskript (Övrigt vetenskapligt)
  • 11.
    Díaz-Ramos, L. Aranzazú
    et al.
    Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, UK.
    O'Hara, Andrew
    Örebro universitet, Institutionen för naturvetenskap och teknik. Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, UK.
    Kanagarajan, Selvaraju
    Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden; School of Science & Technology, Örebro Life Science Center, Örebro University, Örebro, Sweden.
    Farkas, Daniel
    Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Jenkins, Gareth I
    Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, UK.
    Difference in the action spectra for UVR8 monomerisation and HY5 transcript accumulation in Arabidopsis2018Ingår i: Photochemical and Photobiological Sciences, ISSN 1474-905X, E-ISSN 1474-9092, Vol. 17, nr 8, s. 1108-1117Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The photoreceptor UV RESISTANCE LOCUS 8 (UVR8) activates photomorphogenic responses when plants are exposed to ultraviolet-B (UVB) light. However, whereas the absorption spectrum of UVR8 peaks at 280 nm, action spectra for several photomorphogenic UV-B responses show maximal photon effectiveness at 290-300 nm. To investigate this apparent discrepancy we measured the effectiveness of UV wavelengths in initiating two responses in Arabidopsis: photoconversion of homodimeric UVR8 into the monomeric form, which is active in signaling, and accumulation of transcripts of the ELONGATED HYPOCOTYL 5 (HY5) transcription factor, which has a key role in UVR8-mediated responses. When purified UVR8 or Arabidopsis leaf extracts were exposed to UV light monomerisation was maximal at approximately 280 nm, which correlates with the UVR8 absorption spectrum. When intact plants were exposed to UV, monomerisation was most strongly initiated at approximately 290 nm, and this shift in maximal effectiveness could be explained by strong absorption or reflectance at 280 nm by leaf tissue. Notably, the action spectrum for accumulation of HY5 transcripts in the same leaf tissue samples used to assay UVR8 dimer/monomer status peaked at approximately 300 nm. Possible reasons for the difference in maximal photon effectiveness of UVR8 monomerisation and HY5 transcript accumulation in leaf tissue are discussed.

  • 12.
    Elmabsout, Ali Ateia
    et al.
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Kumawat, Ashok K.
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Saenz-Méndez, Patricia
    Computational Chemistry and Biology Group, Facultad de Química, UdelaR, Montevideo, Uruguay.
    Krivospitskaya, Olesya
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Sävenstrand, Helena
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Olofsson, Peder S.
    Department of Medicine, Karolinska Institutet, Center for Molecular Medicine, Stockholm, Sweden; Laboratory of Biomedical Science, The Feinstein Institute for Medical Research, North Shore-LIJ Health System, Manhasset NY, United States of America.
    Eriksson, Leif A.
    Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Valen, Guro
    Department of Physiology, Institute of Basic Medical Science and Center for Heart Failure Research, University of Oslo, Oslo, Norway.
    Törmä, Hans
    Department of Medical Sciences, Dermatology and Venereology, Uppsala University, Uppsala, Sweden.
    Sirsjö, Allan
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Cloning and functional studies of a splice variant of CYP26B1 expressed in vascular cells2012Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, nr 5, artikel-id e36839Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: All-trans retinoic acid (atRA) plays an essential role in the regulation of gene expression, cell growth and differentiation and is also important for normal cardiovascular development but may in turn be involved in cardiovascular diseases, i.e. atherosclerosis and restenosis. The cellular atRA levels are under strict control involving several cytochromes P450 isoforms (CYPs). CYP26 may be the most important regulator of atRA catabolism in vascular cells. The present study describes the molecular cloning, characterization and function of atRA-induced expression of a spliced variant of the CYP26B1 gene.

    Methodology/Principal Findings: The coding region of the spliced CYP26B1 lacking exon 2 was amplified from cDNA synthesized from atRA-treated human aortic smooth muscle cells and sequenced. Both the spliced variant and full length CYP26B1 was found to be expressed in cultured human endothelial and smooth muscle cells, and in normal and atherosclerotic vessel. atRA induced both variants of CYP26B1 in cultured vascular cells. Furthermore, the levels of spliced mRNA transcript were 4.5 times higher in the atherosclerotic lesion compared to normal arteries and the expression in the lesions was increased 20-fold upon atRA treatment. The spliced CYP26B1 still has the capability to degrade atRA, but at an initial rate one-third that of the corresponding full length enzyme. Transfection of COS-1 and THP-1 cells with the CYP26B1 spliced variant indicated either an increase or a decrease in the catabolism of atRA, probably depending on the expression of other atRA catabolizing enzymes in the cells.

    Conclusions/Significance: Vascular cells express the spliced variant of CYP26B1 lacking exon 2 and it is also increased in atherosclerotic lesions. The spliced variant displays a slower and reduced degradation of atRA as compared to the fulllength enzyme. Further studies are needed, however, to clarify the substrate specificity and role of the CYP26B1 splice variant in health and disease.

  • 13.
    Elmabsout, Ali
    et al.
    Örebro universitet, Hälsoakademin.
    Kumawat, Ashok K.
    Örebro universitet, Hälsoakademin.
    Karlsson, Magnus
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Krivospitskaya, Olesya
    Örebro universitet, Hälsoakademin.
    Sävenstrand, Helena
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Hans, Törmä
    Uppsala universitet, Uppsala, Sweden.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Eriksson, Leif A
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sirsjö, Allan
    Örebro universitet, Hälsoakademin.
    Cloning and functional studies of a splice variant of CYP26B1: a cellular storage protein for all-trans retinoic acid2010Ingår i: In Vivo, ISSN 0258-851X, E-ISSN 1791-7549, Vol. 24, nr 3, s. 345-346Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background

    All-trans retinoic acid (atRA) plays an essential role in the regulation of gene expression, cell growth and differentiation and is also important for normal cardiovascular development but may in turn be involved in cardiovascular diseases, i.e. atherosclerosis and restenosis. The cellular atRA levels are under strict control involving several cytochromes P450 isoforms (CYPs). CYP26 may be the most important regulator of atRA catabolism in vascular cells. The present study describes the molecular cloning, characterization and function of atRA-induced expression of a spliced variant of the CYP26B1 gene.

    Methodology/Principal Findings

    The coding region of the spliced CYP26B1 lacking exon 2 was amplified from cDNA synthesized from atRA-treated human aortic smooth muscle cells and sequenced. Both the spliced variant and full length CYP26B1 was found to be expressed in cultured human endothelial and smooth muscle cells, and in normal and atherosclerotic vessel. atRA induced both variants of CYP26B1 in cultured vascular cells. Furthermore, the levels of spliced mRNA transcript were 4.5 times higher in the atherosclerotic lesion compared to normal arteries and the expression in the lesions was increased 20-fold upon atRA treatment. The spliced CYP26B1 still has the capability to degrade atRA, but at an initial rate one-third that of the corresponding full length enzyme. Transfection of COS-1 and THP-1 cells with the CYP26B1 spliced variant indicated either an increase or a decrease in the catabolism of atRA, probably depending on the expression of other atRA catabolizing enzymes in the cells.

    Conclusions/Significance

    Vascular cells express the spliced variant of CYP26B1 lacking exon 2 and it is also increased in atherosclerotic lesions. The spliced variant displays a slower and reduced degradation of atRA as compared to the full-length enzyme. Further studies are needed, however, to clarify the substrate specificity and role of the CYP26B1 splice variant in health and disease.

  • 14.
    Enroth, Cristofer
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Crystal structure of a protein, structurally related to glycosyltransferases, encoded in the Rhodobacter blasticus atp operon2008Ingår i: Biochimica et Biophysica Acta - Proteins and Proteomics, ISSN 1570-9639, E-ISSN 1878-1454, Vol. 1784, nr 2, s. 379-384Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The F1-ATP synthase atp operon in the proteobacterium Rhodobacter blasticus contains six open reading frames, encoding six hypothetical proteins. Five of these subunits, in the stoichiometry (ab)3gde make up the catalytic F1-ATP synthase complex similarly in bacteria, chloroplasts and mitochondria. The sixth gene of the Rb. blasticus atp operon, urf6, shows very little sequence homology to any protein of known structure or function. The gene has previously been cloned, the product (called majastridin) has been heterologously expressed in Escherichia coli, and purified to high homogeneity (Brosché et al. (1998) Eur. J. Biochem. 255: 87-92). We have solved the X-ray crystal structure and refined a model of majastridin to atomic resolution. Here we present the crystal structures of apo-majastridin and the complex of majastridin with Mn2+ and UDP and show it has extensive structural similarity to glycosyltransferases (EC 2.4). This is the first structure determined from a new group of distantly related bacterial proteins of at least six members. They share the identical amino acids that bind Mn2+and a triplet of amino acids in the putative sugar-binding site.

  • 15.
    Eriksson, Leif A.
    et al.
    Göteborgs universitet, Göteborg.
    Sirsjö, Allan
    Örebro universitet, Institutionen för medicinska vetenskaper.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Tetrazole derivatives as cytochrome p450 inhibitors2019Patent (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    According to the invention there is provided a compound of formula I, wherein Rand Rhave meanings given in the description, which compounds are useful in the treatment of skin disorders and other diseases.

  • 16.
    Eriksson, Leif A.
    et al.
    Gothrnburgs University, Gothenburg, Sweden.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Chemistry of vitamin B6 under oxidative stress2012Ingår i: UV4growth COST-Action FA0906: Plant responses to ultraviolet radiation – roles of antioxidants and pro-oxidants / [ed] Petra Majer, Köpenhamn: University of Copenhagen , 2012, s. 28-28Konferensbidrag (Refereegranskat)
    Abstract [en]

    Vitamin B6, or pyridoxine, is the precursor of the biologically active derivatives pyridoxal-5’-phosphate and pyridoxamine-5’-phosphate (Fig.1), with functional roles in a number of different enzymes. Pyridoxine itself is a cofactor of several enzymes that catalyze decarboxylations, transaminations, and racemations of amino acids. Bacteria, fungi, and plants produce their own vitamin B6, whereas parasitic organisms and higher animals have to acquire vitamin B6 through nutrient intake.

    Lately, pyridoxine biosynthesis-deficient mutants of fungi and yeast have been shown to be sensitive to reactive oxygen species (ROS) such as singlet oxygen and hydrogen peroxide. This suggests that vitamin B6 and its derivatives are also involved in stress tolerance in living organisms, especially in alleviating oxidative stress. In eukaryotes, stress resistance has been implied to involve pyridoxine-dependent singlet oxygen quenching, whereby the pyridoxine itself would react with and quench the singlet oxygen. The oxidative stress-protective effect of pyridoxine has also been described both in red blood cells and in lens cells in animals. Pyridoxine itself was found to be the most effective of the vitamin B6 species, twice as effective as pyridoxal-5’-phosphate, and as effective as vitamin E.

     Knowledge about this novel mechanism of reaction between pyridoxine or its derivatives (cf. Figure 1) and singlet oxygen and other ROS is however very limited. However, since both the aldehyde (pyridoxal) and the amino (pyridoxamine) derivatives only to a small extent influence the rate of reaction, these moieties are probably not involved. Also, since the heteroaromatic absorbance peak at 323 nm disappears during the reaction, at least one of the targets for singlet oxygen is most likely the core of the aromatic ring, leading to ring opening.

    In order to shed more light on the possible role of pyridoxine in stress tolerance / protection we herein report on computational studies of possible reaction mechanisms between pyridoxine and different ROS (singlet oxygen, superoxide and hydrogen peroxide) by means of density functional theory (DFT) based methods. It is concluded that the compound has an extremely high quenching power towards hydroxyl radicals. We furthermore explore the explicit UV-induced photolysis pathways of the compound, as well as enzymatic degradation (ring-opening) by bacterial flavoprotein monooxygenases.

  • 17. Gittins, John R.
    et al.
    Schuler, Mary A.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Identification of a novel nuclear factor-binding site in the Pisum sativum sad gene promoters2002Ingår i: Biochimica et Biophysica Acta, Gene Structure and Expression, ISSN 0167-4781, E-ISSN 1879-2634, Vol. 1574, nr 3, s. 231-244Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    DNA fragments containing the 5' promoter regions of the Pisum sativum sadA and sadC genes were amplified from genomic DNA, cloned and sequenced. These sequences contain a number of conserved cis-acting elements, which are potentially involved in stress-induced transcription of the sad genes. To determine whether any of the identified elements are active in binding nuclear factors in vitro, 11 60-bp overlapping (by 30 bp) DNA probe fragments covering the proximal sadC promoter sequence (360 bp) were used in electrophoretic mobility shift assays with competition. Binding activities were compared in nuclear extracts from control, UV-B-stressed and wounded pea leaves. The pattern of DNA binding was almost identical with all three extracts, with one 30-bp region being the predominant site for factor binding. Using overlapping sub-fragments of this region, the majority of the specific binding could be attributed to the novel 11-bp GC-rich sequence GTGGCGCCCAC. An almost identical sequence is conserved in the sadA promoter. This motif has features in common with a number of recognised cis-elements, which suggests a possible binding site for factors which play a role in regulating sad gene transcription.

  • 18.
    Hadad, Ronza
    et al.
    Örebro Life Science Center, School of Science and Technology, Örebro University, Örebro, Sweden; Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Marks, Ellen
    Department of Medical Microbiology and Immunology, University of Gothenburg, Gothenburg, Sweden.
    Kalbina, Irina
    Örebro universitet, Institutionen för naturvetenskap och teknik. Örebro Life Science Center, Örebro University, Örebro, Sweden.
    Schön, Karin
    Department of Medical Microbiology and Immunology, University of Gothenburg, Gothenburg, Sweden.
    Unemo, Magnus
    Örebro universitet, Institutionen för medicinska vetenskaper. Department of Laboratory Medicine, Örebro University Hospital, Örebro, Sweden.
    Lycke, Nils
    Department of Medical Microbiology and Immunology, University of Gothenburg, Gothenburg, Sweden.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik. Örebro Life Science Center, Örebro University, Örebro, Sweden.
    Andersson, Sören
    Örebro universitet, Institutionen för medicinska vetenskaper. Department of Laboratory Medicine, Örebro University Hospital, Örebro, Sweden.
    Protection against genital tract Chlamydia trachomatis infection following intranasal immunization with a novel recombinant MOMP VS2/4 antigen2016Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 124, s. 1078-1086Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The asymptomatic nature of most Chlamydia trachomatis infections and the lack of appropriate effects by current prevention and management call for vaccine development. We evaluated a recombinant subunit vaccine candidate based on the major outer membrane protein variable segments 2 and 4 (MOMP VS2/4). To achieve maximal immunogenicity and ease of production and purification, MOMP VS2/4 was constructed by using highly immunogenic sequences of MOMP only, thereby minimizing the presence of hydrophobic regions, and spacing the immunogenic epitopes with a flexible amino acid sequence. A purification tag was also added. The MOMP VS2/4 was given intranasally, with or without intravaginal boost, with cholera toxin (CT) adjuvant to C57BL/6 mice, which were screened for immunogenicity and protection against a live challenge infection with C. trachomatis serovar D. Bacterial shedding, cell-mediated responses, and antibody responses were monitored. Immunized mice exhibited significantly less bacterial shedding and were better protected against infertility as compared to unimmunized control mice. Immunizations stimulated both systemic and local specific antibody (IgG1, IgG2c, and IgA) responses, and primed T cells that produced interferon-c and interleukins 13 and 17 upon challenge with recall antigen. Thus, MOMP VS2/4, in combination with CT adjuvant, stimulated Th1, Th2, and Th17 effector cells, and generated protective immunity associated with less pathology. We regard MOMP VS2/4 as a promising candidate for further development into a mucosal chlamydial vaccine.

  • 19.
    Hadad, Ronza
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Schön, Karin
    University of Gothenburg, Gothenburg, Sweden.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Andersson, Sören
    Örebro University Hospital, Örebro, Sweden.
    Unemo, Magnus
    Örebro University Hospital, Örebro, Sweden.
    Lycke, Nils
    University of Gothenburg, Gothenburg, Sweden.
    Optimization of infection in murine model with Chlamydia trachomatis for vaccine studies2013Ingår i: Chlamydia Basic Research Society: 2013 biannual meeting, 2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    Background and Significance: Vaccine studies for Chlamydia trachomatis (Ct) have been hampered by the lack of an ideal murine model. Ct is not ideal for infection and subsequent pathology as it is a human pathogen and C. muridarum (Cm) may not be suitable due to vaccine specificity for Ct. There is currently no standardization of chlamydial infections in murine models concerning mouse strain, infecting agent and dose.

     

    Objectives: To investigate the Ct infection in mice, using different suppliers of mice, doses and the infective agents of Ct serovars D, E and Cm.

     

    Methods: C57BL/6 mice (Taconic; Harlan; in-house breeding mice) were inoculated intravaginally with 103-105 chlamydia  elementary bodies (EB). Vaginal samples were collected at 7-8 days intervals and analyzed using MicroTrak II Chlamydia EIA kit.

     

    Results: Taconic mice inoculated with Ct D with 105 EB showed the strongest infection with 30% of mice infected at day 21 (d21) as seen in figure 1. The number of infected mice and detected antigen (not shown) decreased rapidly after the first time-point (d8). In figure 2 infective agents were analyzed. Ct E did not infect any mice despite using a tenfold increased dose. Cm infection was detectable in 80% of the mice for up to d21.

     

    Conclusions: Ct D infected the mice for a period of 2-3 weeks. There was only a small difference between the suppliers in favor for Harlan mice. Ct D 105 EB was the infectious dose with the highest number of infected mice over time, however the appropriateness of that high bacterial load must be considered. Ct E did not infect these mice and Cm, a mouse pneumonitis strain, infected all mice and had the longest duration of infection. However, for vaccine studies, Cm may not be suitable due to lack of cross reactivity and Ct may still be used however vaginal sampling must be more frequent early on to show significant differences in bacterial shedding between immunized and non-immunized mice. 

  • 20.
    Hansson, Charlotta
    et al.
    Department of Microbiology and Immunology, University of Gothenburg, Gothenburg, Sweden.
    Schön, Karin
    Department of Microbiology and Immunology, University of Gothenburg, Gothenburg, Sweden.
    Kalbina, Irina
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Andersson, Sören
    Region Örebro län. Sch Sci & Technol, Orebro Life Sci Ctr, Univ Orebro, Orebro, Sweden; Department of Laboratory Medicine, Örebro University Hospital, Örebro, Sweden .
    Bokarewa, Maria I.
    Department of Rheumatology and Inflammation Research, University of Gothenburg, Gothenburg, Sweden.
    Lycke, Nils Y.
    Department of Microbiology and Immunology, University of Gothenburg, Gothenburg, Sweden.
    Feeding transgenic plants that express a tolerogenic fusion protein effectively protects against arthritis2016Ingår i: Plant Biotechnology Journal, ISSN 1467-7644, E-ISSN 1467-7652, Vol. 14, nr 4, s. 1106-1115Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although much explored, oral tolerance for treatment of autoimmune diseases still awaits the establishment of novel and effective vectors. We investigated if the tolerogenic CTA1(R7K)-COL-DD fusion protein can be expressed in edible plants and in this way induce oral tolerance and protect against arthritis. The fusion protein was recombinantly expressed in Arabidopsis thaliana plants, which were fed to H-2q restricted DBA/1 mice to assess the preventive effect on collagen-induced arthritis (CIA). The treatment resulted in fewer mice exhibiting disease and arthritis scores were significantly reduced. Immune suppression was evident in treated mice and serum biomarkers for inflammation as well as anti-collagen IgG responses were reduced. In spleen draining and lymph nodes, CD4+ T cell responses were reduced. Concomitant with a reduced effector T cell activity with lower IFNg, IL-13 and IL-17A production we observed an increase in IL-10 production to recall antigen stimulation in vitro, suggesting reduced Th1, Th2 and Th17 activity subsequent to upregulated IL-10 and regulatory T cell (Treg) functions. The present study shows that edible plants expressing a tolerogen were effective at stimulating CD4 T cell tolerance and in protecting against CIA disease. Our study conveys optimism as to the potential of using edible plants for oral treatment of rheumatoid arthritis.

  • 21.
    Hideg, Éva
    et al.
    Pécs University, Pécs, Hungary.
    Jansen, Marcel A. K.
    University College of Cork, Cork, Ireland.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    UV-B exposure, ROS, and stress: inseparable companions or loosely linked associates?2013Ingår i: Trends in Plant Science, ISSN 1360-1385, E-ISSN 1878-4372, Vol. 18, nr 2, s. 107-115Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ultraviolet-B (UV-B) radiation has long been perceived as a stressor. However, a conceptual U-turn has taken place, and UV-B damage is now considered rare. We question whether UV-stress and UV-B-induced reactive oxygen species (ROS) are still relevant concepts, and if ROS-mediated signaling contributes to UV-B acclimation. Measurements of antioxidants and of antioxidant genes show that both low and high UV-B doses alter ROS metabolism. Yet, there is no evidence that ROS control gene expression under low UV-B. Instead, expression of antioxidant genes is linked to the UV RESISTANCE LOCUS 8 pathway. We hypothesize that low UVB doses cause ‘eustress’ (good stress) and that stimulispecific signaling pathways pre-dispose plants to a state of low alert that includes activation of antioxidant defenses.

  • 22.
    Hideg, Éva
    et al.
    University of Pécs, Pécs, Hungary.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    The effects of UV-B on the biochemistry and metabolism of plants2017Ingår i: UV-B radiation and plant life: molecular biology to ecology / [ed] Brian R. Jordan, Wallingford, UK: CABI Publishing, 2017, s. 90-110Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    This chapter focuses on the effects of UV-B radiation on the biochemistry and metabolism of plants and their underlying mechanisms. Information on the UV-inducible metabolites and protection responses of plants against UV-B radiation are also discussed.

  • 23.
    Jansen, Marcel A. K.
    et al.
    School of Biological Earth and Environmental Sciences, University College Cork, Cork, Ireland; Global Change Research Institute CAS, Brno, Czech Republic.
    Bilger, Wolfgang
    Botanisches Institut, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.
    Hideg, Éva
    Institute of Biology, University of Pécs, Pécs, Hungary.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Urban, Otmar
    Global Change Research Institute CAS, Brno, Czech Republic.
    Interactive effects of UV-B radiation in a complex environment2019Ingår i: Plant physiology and biochemistry (Paris), ISSN 0981-9428, E-ISSN 1873-2690, Vol. 134, s. 1-8Artikel i tidskrift (Refereegranskat)
  • 24.
    Jordan, Brian R
    et al.
    Lincoln University, Lincoln, New Zeeland.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Wargent, Jason J
    Massey University, Palmerston North, New Zealand.
    What role does UVB play in determining photosynthesis?2016Ingår i: Handbook of Photosynthesis / [ed] Mohammad Pessarakli, Boca Raton: CRC Press, 2016, 3, s. 275-286Kapitel i bok, del av antologi (Refereegranskat)
  • 25.
    Kalbin, Georgi
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Hidema, Jun
    Brosché, Mikael
    Kumagai, Tadashi
    Bornman, Janet F.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    UV-B-induced DNA damage and expression of defence genes under UV-B stress: tissue-specific molecular marker analysis in leaves2001Ingår i: Plant, Cell and Environment, ISSN 0140-7791, E-ISSN 1365-3040, Vol. 24, nr 9, s. 983-990Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to investigate the regulatory effect of ultraviolet-B (UV-B) radiation on a number of key stress response genes found in the epidermis and mesophyll of Pisum sativum L., Argenteum mutant. This mutant was chosen for the ease with which the entire epidermis can be removed from the mesophyll tissue. An additional goal was to explore the potential modifying effect of pre-acclimation of plants to UV-B radiation prior to exposure by UV-B during treatment. Results showed that mRNA accumulation was similar during acute short-term UV-B exposure for chalcone synthase (Chs) and short-chain alcohol dehydrogenase (SadA) in both epidermis and mesophyll. In contrast, the mRNA levels differed considerably between tissues for phenylalanine ammonia lyase, chalcone isomerase and lipid transfer protein. After 24 h incubation in visible light after cessation of UV-B exposure, the regulation of mRNA levels also differed between Chs and SadA, the former showing no expression in the epidermis and the latter none in the mesophyll. Acclimation to low UV-B levels before acute exposures resulted in delayed induction of Chs and SadA. Measurements of UV-B-induced cyclobutane pyrimidine dimers (CPDs) showed a greater formation in epidermis than in mesophyll. In addition, acclimation at low UV-B levels resulted in significantly higher basal levels of CPDs than in non-acclimated plants in both mesophyll and epidermis and also in increased damage in concomitant acute exposures. The lack of correlation between the number of CPDs and levels of transcripts for defence genes, indicates that DNA damage does not control transcription of these genes.

  • 26.
    Kalbin, Georgi
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Li, Shaoshan
    Örebro universitet, Institutionen för naturvetenskap.
    Olsman, Helena
    Örebro universitet, Institutionen för naturvetenskap.
    Pettersson, Mikael
    Engwall, Magnus
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Effects of UV-B in biological and chemical systems: equipment for wavelength dependence determination2005Ingår i: Journal of Biochemical and Biophysical Methods, ISSN 0165-022X, E-ISSN 1872-857X, Vol. 65, nr 1, s. 1-12Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The thinning of the stratospheric ozone layer has prompted a large number of studies of UV-B-induced effects in biological and chemical systems. The wavelength dependency of such effects is of interest from mechanistic, physiological or economic points of view. Here, we describe an apparatus for determining the wavelength dependency of UV-B effects in biological and chemical systems. The apparatus consists of a high intensity UV radiation source and narrow bandpass filters to produce UV radiation in even intervals (between 280 and 360 nm). The usefulness of the equipment is demonstrated in two different systems: 1) Chalcone synthase (CHS) gene is up-regulated by UV-B radiation. Therefore quantitative analysis of the CHS gene expression was chosen in the present investigation for studies of the wavelength dependency of gene expression regulation in plants. Maximum induction of CHS expression was found at 300 nm with a 12-fold induction compared with the control; 2) The wavelength dependency of formation of dioxin-like photoproducts from the brominated flame retardant decabrominated diphenyl ether (DeBDE) is described. This is an example of UV-B-induced conversion of non-toxic species into a number of products of which some may be toxic in the environment. In the UV interval studied, the highest dioxin-like activity was found in the sample irradiated at 330 nm and therefore this wavelength is most important for the mechanism involved in photoconversion of DeBDE.

  • 27.
    Kalbina, Irina
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Engstrand, Lars
    Dept Bacteriol, Swedish Inst Infect Dis Control SMI, Solna, Sweden.
    Andersson, Sören
    Örebro University Hospital, Örebro, Sweden; Dept Bacteriol, Swedish Inst Infect Dis Control SMI, Solna, Sweden.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Expression of Helicobacter pylori TonB Protein in Transgenic Arabidopsis thaliana: toward production of vaccine antigens in plants2010Ingår i: Helicobacter, ISSN 1083-4389, E-ISSN 1523-5378, Vol. 15, nr 5, s. 430-437Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: The aim of this study was to produce a recombinant version of the highly antigenic Helicobacter pylori TonB (iron-dependent siderophore transporter protein HP1341) in transgenic plants as a candidate oral vaccine antigen. Materials and Methods: Using Agrobacterium-mediated gene transfer, we introduced three different constructs of the tonB gene into the genome of the model plant Arabidopsis thaliana. We investigated transgene insertion by PCR, produced TonB antibodies for analysis of the production of the recombinant protein in plants, verified the identity of the protein produced by mass spectrometry analysis, and analyzed the number of genetic inserts in the plants by Southern blotting. Results: Three different constructs of the expression cassette (full-length tonB, tonB truncated in the 5' end removing the codons for a transmembrane helix, and the latter construct with codons for the endoplasmic reticulum SEKDEL retention signal added to the 3' end) were used to find the most effective way to express the TonB antigen. Production of TonB protein was detected in plants transformed with each of the constructs, confirmed by both Western blotting and mass spectrometry analysis. No considerable differences in protein expression from the three different constructs were observed. The protein concentration in the plants was at least 0.05% of the total soluble proteins. Conclusions: The Helicobacter pylori TonB protein can be produced in Arabidopsis thaliana plants in a form that is recognizable by rabbit anti-TonB antiserum. These TonB-expressing plants are highly suitable for animal studies of oral adminstration as a route for immunization against Helicobacter infections.

  • 28.
    Kalbina, Irina
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Orebro Life Science Center.
    Lagerqvist, Nina
    Department of Microbiology, Public Health Agency of Sweden, Solna, Sweden; Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
    Moiane, Bélisario
    Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden; Eduardo Mondlane University, Maputo, Mozambique.
    Ahlm, Clas
    Department of Clinical Microbiology, Umeå University, Umeå, Sweden.
    Andersson, Sören
    Örebro universitet, Institutionen för medicinska vetenskaper. Örebro Life Science Center, Department of Science and Technology, Örebro University, Örebro, Sweden; Department of Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Falk, Kerstin I.
    Department of Microbiology, Public Health Agency of Sweden, Solna, Sweden; Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
    Arabidopsis thaliana plants expressing Rift Valley fever virus antigens: Mice exhibit systemic immune responses as the result of oraladministration of the transgenic plants2016Ingår i: Protein Expression and Purification, ISSN 1046-5928, E-ISSN 1096-0279, Vol. 127, s. 61-67Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The zoonotic Rift Valley fever virus affects livestock and humans in Africa and on the Arabian Peninsula.The economic impact of this pathogen due to livestock losses, as well as its relevance to public health,underscores the importance of developing effective and easily distributed vaccines. Vaccines that can bedelivered orally are of particular interest.

    Here, we report the expression in transformed plants (Arabidopsis thaliana) of Rift Valley fever virusantigens. The antigens used in this study were the N protein and a deletion mutant of the Gn glycoprotein.Transformed lines were analysed for specific mRNA and protein content by RT-PCR and Westernblotting, respectively. Furthermore, the plant-expressed antigens were evaluated for their immunogenicityin mice fed the transgenic plants. After oral intake of fresh transgenic plant material, a proportionof the mice elicited specific IgG antibody responses, as compared to the control animals that were fedwild-type plants and of which none sero-converted.

    Thus, we show that transgenic plants can be readily used to express and produce Rift Valley Fever virusproteins, and that the plants are immunogenic when given orally to mice. These are promising findingsand provide a basis for further studies on edible plant vaccines against the Rift Valley fever virus.

  • 29.
    Kalbina, Irina
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Li, Shaoshan
    Björn, Lars Olof
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Wavelength dependence of expression of UV-B-induced molecular markers in Arabidopsis thalianaManuskript (Övrigt vetenskapligt)
  • 30.
    Kalbina, Irina
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Li, Shaoshan
    Örebro universitet, Institutionen för naturvetenskap.
    Kalbin, Georgi
    Örebro universitet, Institutionen för naturvetenskap.
    Björn, Lars Olof
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Two separate UV-B radiation wavelength regions control expression of different molecular markers in Arabidopsis thaliana2008Ingår i: Functional Plant Biology, ISSN 1445-4408, E-ISSN 1445-4416, Vol. 35, nr 3, s. 222-227Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Fluence-response curves were obtained at nine wavelengths in the interval 280-360 nm for mRNA transcripts of four molecular markers induced by ultraviolet-B (UV-B) radiation in Arabidopsis thaliana: CHS (encoding chalcone synthase), PDX1.3 (encoding an enzyme involved in formation of pyridoxine), MEB5.2 (encoding a protein with unknown function but which is strongly up-regulated by UV-B), and LHCB1*3 (encoding a chlorophyll a/b binding protein). Intact Arabidopsis plants were irradiated for 3h using a high intensity deuterium radiation source and narrow bandwith filters (Kalbin et al. 2005, J. Biochem. Biophys. Meth. 65, 1-12) without supplementary PAR. The results obtained suggest the existence of two distinct UV-B signal responses: one sensitive between 300 and 310 nm and the other sensitive around 280-290 nm. Among the investigated molecular markers, CHS and PDX1.3 were regulated through the chromophore absorbing around 300 nm, whereas MEB5.2 and LHCB1*3 were regulated through the chromophore absorbing at 280-290 nm. The results obtained show that at least two signal transduction pathways exist that regulate gene expression as a result of absorption of UV-B radiation in plants.

  • 31.
    Kalbina, Irina
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Marks, Ellen
    University of Gothenburg, Gothenburg, Sweden.
    Lycke, Nils
    University of Gothenburg, Gothenburg, Sweden.
    Lindh, Ingrid
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Unemo, Magnus
    Örebro University Hospital, Örebro, Sweden.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Andersson, Sören
    Örebro University Hospital, Örebro, Sweden.
    Construction, immunogenicity and protective efficacy in mice of a prototype chimeric Chlamydia trachomatis MOMP vaccine candidate antigen2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    A chimeric gene construct of Chlamydia trachomatis serovar E major outer membrane protein (MOMP) was designed, and expressed as a candidate vaccine antigen. The construct was based on known T and B cell epitopes located in the variable segment (VS) 2 and 4 loops of MOMP, and successfully expressed and purified in a recombinant Escherichia coli system. BALB/c mice were immunized intranasally with the chimeric MOMP antigen and Cholera toxin (CT) adjuvant, three immunizations with 10 days intervals. A final boost with the identical antigen preparation was given intravaginally. Challenge with live C. trachomatis serovar D was performed 10 days after boost. Antibodies in serum and vaginal washes were determined with the identical chimeric MOMP construct as antigen in ELISAs. All mice in vaccine groups (N=10/group and experiment) developed a strong antigen-specific IgG response in serum, and some also had detectable antigen-specific IgG in vaginal washes. An IgA response, albeit weaker, was detected in some of the mice both in serum and in vaginal washes.

    After challenge with C. trachomatis, 80 and 100% of the mice became infected in two experiments, respectively. However, the vaccinated groups cleared the infection significantly faster than control groups (all vaccinated mice healthy day 24 [90% day 16], compared to day 40 for controls).

    Thus, the new chimeric MOMP antigen construct gave rise to a significant immune response in mice (s-IgG). It also conferred substantial protection to infection caused by genital C. trachomatis infection of a different subtype.

  • 32.
    Kalbina, Irina
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    An Arabidopsis mutant responsive to UV-B irradiationManuskript (Övrigt vetenskapligt)
  • 33.
    Kalbina, Irina
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Supplementary ultraviolet-B irradiation reveals differences in stress responses between Arabidopsis thaliana ecotypes2005Manuskript (preprint) (Övrigt vetenskapligt)
  • 34.
    Kalbina, Irina
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Supplementary ultraviolet-B irradiation reveals differences in stress responses between Arabidopsis thaliana ecotypes2006Ingår i: Plant, Cell and Environment, ISSN 0140-7791, E-ISSN 1365-3040, Vol. 29, nr 5, s. 754-763Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Irradiation of Arabidopsis thaliana ecotypes C24, Wassilewskija (Ws) and Columbia-0 (Col-0) with supplementary ultraviolet-A+B (UV-A+B) radiation revealed ecotype-specific differences in expression of the gene for the pathogenesis-related protein PR-5. C24 showed an increased expression level of PR-5 (5- and 20-fold higher compared with Col-0 and Ws, respectively). Expression of other molecular markers such as CHS (encoding chalcone synthase), MEB5.2 [encoding a gene strongly up-regulated by ultraviolet-B (UV-B)] and PYROA [encoding a pyridoxine (Vitamin B6) biosynthesis enzyme] only showed slight differences between ecotypes. Oxidative stress during UVA+B exposure was monitored by staining for H2O2. This analysis also revealed important ecotype-specific differences. 'H2O2 hot spots' were found in C24, whereas an even distribution of H2O2 was found in Ws and Col-0. Necrotic lesions also appeared on C24 leaves after prolonged UV-B exposure. There was a reverse correlation between the H2O2 steady-state concentration and the PR-5 gene expression; Ws showed the highest level of H2O2 accumulation but the lowest expression level of the PR-5 gene. Furthermore, application of paraquat on the rosettes led to similar PR-5 expression and H2O2 accumulation patterns as were found after UV-A+B irradiation. The observed ecotypic differences were also reflected in a statistically significant UV-B-dependent decrease in biomass, rosette size and leaf area for Ws, but not for C24 and Col-0. Our results show that a significant ecotype-specific genetic variability in general UV-B responses in Arabidopsis exists. Moreover, the signal transduction or gene regulation pathway for PR-5 differs from the other molecular markers used in this study.

  • 35.
    Kalbina, Irina
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    The role of NADPH oxidase and MAP kinase phosphatase 1 in UV-B-dependent gene expression in ArabidopsisManuskript (Övrigt vetenskapligt)
  • 36.
    Kalbina, Irina
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    The role of NADPH oxidase and MAP kinase phosphatase in UV-B-dependent gene expression in Arabidopsis2006Ingår i: Plant, Cell and Environment, ISSN 0140-7791, E-ISSN 1365-3040, Vol. 29, nr 9, s. 1783-1793Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Plant responses to supplementary UV-B irradiation have been reported to include formation of reactive oxygen species (ROS), hydrogen peroxide, in particular, and regulation by mitogen-activated protein kinase (MAPK) cascades which in turn are fine-tuned by MAPK phosphatases (MKPs). Here we present direct genetic evidence for the involvement of plasma membrane NADPH oxidase, a source of superoxide and hydrogen peroxide in the apoplasts, in UV-B signalling in Arabidopsis thaliana, by analysis of gene expression of the UV-B molecular markers in NADPH oxidase (atrbohD, F and DF) and MAP kinase phosphatase 1 (MKP1) knockout mutants (mkp1). Whereas the NADPH oxidase mutants were affected in UV-B-dependent CHS, PYROA and MEB5.2 gene expression, the mkp1 mutant was affected in the general expression pattern of the pathogenesis-related (PR) and PDF1.2 genes. The results indicate involvement of MKP1 in repressive action on gene expression of more general stress response pathways, similar to those activated by pathogen attack, while NADPH oxidase is involved in quantitative (rather than absolute) regulation of more UV-B-specific genes. The expressions of the molecular markers in the knockout mutant mkp1 and in its complemented lines (lines 6 and 10) were similar, as opposed to the responses of the corresponding wild-type Wassilewskija-4 (Ws-4). Lines 6 and 10 showed much higher MKP1 mRNA than Ws-4 but did not complement the mutant. This suggests a complex dependency of the MAPK phosporylation level of the PR and PDF1.2 genes. Both NADPH oxidase mutants and the mkp1 mutant phenotypically responded to UV-B by growth retardation.

  • 37.
    Kalbina, Irina
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Wallin, Anita
    Uppsala universitet, Uppsala, Sweden.
    Lindh, Ingrid
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Engström, Peter
    Uppsala universitet, Uppsala, Sweden.
    Andersson, Sören
    Örebro University Hospital, Örebro, Sweden.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    A novel chimeric MOMP antigen expressed in Escherichia coli, Arabidopsis thaliana, and Daucus carota as a potential Chlamydia trachomatis vaccine candidate2011Ingår i: Protein Expression and Purification, ISSN 1046-5928, E-ISSN 1096-0279, Vol. 80, nr 2, s. 194-202Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The major outer membrane protein (MOMP) of Chlamydia trachomatis is a highly antigenic and hydrophobic transmembrane protein. Our attempts to express the full-length protein in a soluble form in Escherichia coli and in transgenic plants failed. A chimeric gene construct of C. trachomatis serovar E MOMP was designed in order to increase solubility of the MOMP protein but with retained antigenicity. The designed construct was successfully expressed in E. coli, in Arabidopsis thaliana, and in Daucus carota. The chimeric MOMP expressed in and purified from E. coli was used as antigen for production of antibodies in rabbits. The anti-chimeric MOMP antibodies recognized the corresponding protein in both E. coli and in transgenic plants, as well as in inactivated C. trachomatis elementary bodies. Transgenic Arabidopsis and carrots were characterized for the number of MOMP chimeric genetic inserts and for protein expression. Stable integration of the transgene and the corresponding protein expression were demonstrated in Arabidopsis plants over at least six generations. Transgenic carrots showed a high level of expression of the chimeric MOMP – up to 3% of TSP.

  • 38.
    Kalbina, Irina
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Wallin, Anita
    Uppsala universitet, Uppsala, Sweden.
    Lindh, Ingrid
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Engström, Peter
    Uppsala universitet, Uppsala, Sweden.
    Andersson, Sören
    Universitetssjukhuset i Örebro, Örebro, Sweden.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Expression of chimeric Chlamydia trachomatis MOMP protein antigen in Arabidopsis thaliana and Daucus carota2011Ingår i: Molecular farming: plants as a production platform for high value proteins / [ed] Ann Depicker, Bryssel: COST , 2011, s. 38-38Konferensbidrag (Refereegranskat)
    Abstract [en]

    Urogenital chlamydial infection, caused by Chlamydia trachomatis, is the main sexually transmitted infection in Sweden. Despite active programmes for detection and case finding, nearly 37 000 cases were reported in 2010. Serovar E strains are considered to cause approximately 40-50% of these cases. A vaccine would be highly valuable in order to control the epidemic.

    The major outer membrane protein (MOMP) of Chlamydia trachomatis is a highly antigenic and hydrophobic transmembrane protein. Our attempts to express the full-length protein in a soluble form in transgenic plants failed. A chimeric gene construct of Chlamydia trachomatis serovar E MOMP was designed in order to increase solubility of the MOMP protein but with retained antigenicity. The construct was based on known T and B cell epitopes located in the variable segment (VS) 2 and 4 loops of MOMP.

    The designed construct was successfully expressed in Arabidopsis thaliana, and in Daucus carota. A chimeric MOMP expressed in and purified from E. coli was used as antigen for production of antibodies in rabbits. The anti-chimeric MOMP antibodies recognized the corresponding protein in the transgenic plants, as well as in inactivated C. trachomatis elementary bodies. Transgenic Arabidopsis and carrots were characterized for the number of MOMP chimeric genetic inserts and for protein expression. Stable integration of the transgene and the corresponding protein expression were demonstrated in Arabidopsis plants over at least six generations. Transgenic carrots showed a high level of expression of the chimeric MOMP– up to 3% of TSP.

  • 39.
    Karlsson, Magnus
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sirsjö, Allan
    Örebro universitet, Hälsoakademin.
    Eriksson, Leif A.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Homology Models and Molecular Modeling of Human Retinoic Acid Metabolizing Enzymes Cytochrome P450 26A1 (CYP26A1) and P450 26B1 (CYP26B1)2008Ingår i: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 4, nr 6, s. 1021-1027Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Homology models of cytochrome P450 26A1 and cytochrome P450 26B1 were constructed using the crystal structures of human, CYP2C8, CYP2C9, and CYP3A4 as templates for the model building. The homology models generated were investigated for their docking capacities against the natural substrate all-trans-retinoic acid (atRA), five different tetralone-derived retinoic acid metabolizing blocking agents (RAMBAs), and R115866. Interaction energies (IE) and linear interaction energies (LIE) were calculated for all inhibitors in both homology models after molecular dynamics (MD) simulation of the enzyme-ligand complexes. The results revealed that the homologues had the capacity to distinguish between strong and weak inhibitors. Important residues in the active site were identified from the CYP26A1/B1-atRA complexes. Residues involved in hydrophobic interactions with atRA were Pro113, Phe222, Phe299, Val370,

    Pro371, and Phe374 in CYP26A1 and Leu88, Pro118, Phe222, Phe295, Ile368, and Tyr272 in CYP26B1. Hydrogen bonding interactions were observed between the atRA carboxylate group and Arg 90 in CYP26A1 and with Arg76, Arg95, and Ser369 in CYP26B1.

  • 40.
    Li, Shaoshan
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Anthocyanin accumulation and changes in CHS and PR-5 gene expression in Arabidopsis thaliana after removal of the inflorescence stem (decapitation)2005Ingår i: Plant physiology and biochemistry (Paris), ISSN 0981-9428, E-ISSN 1873-2690, Vol. 43, nr 6, s. 521-525Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Anthocyanin accumulation occurs in rosette leaves of Arabidopsis thaliana within 8 days after removal of the inflorescence stem. Expression of stress-induced genes CHS and PR-5 was strongly up-regulated by stem removal, and was highest on day 4 after decapitation. These levels were 10 and 5 times higher than in the control, respectively. No obvious difference was found in expression of LHCB, MEB5.2, or PYROA genes following stem removal. We demonstrate that removing the inflorescence stem triggers events in Arabidopsis, including pigment accumulation and changes in gene expression of a subset of stress-induced genes, in a tissue distant from the wound site.

  • 41.
    Lindh, Ingrid
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Andersson, Sören
    Universitetssjukhuset i Örebro, Örebro, Sweden.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Plant-based production of HIV antigens: towards a candidate for an edible vaccine2010Ingår i: In Vivo, ISSN 0258-851X, E-ISSN 1791-7549, Vol. 24, nr 3, s. 368-370Artikel i tidskrift (Refereegranskat)
  • 42.
    Lindh, Ingrid
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Bråve, Andreas
    The Public Health Agency of Sweden, Stockholm, Sweden.
    Hallengärd, David
    Karolinska Institute, Stockholm, Sweden.
    Andersson, Sören
    Örebro University Hospital, Örebro, Sweden.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Oral delivery of plant-derived HIV-1 p24 antigen in low doses shows a superior priming effect in mice compared to high doses2012Ingår i: Molecular farming: plants as a production platform for high value proteins : FA action COST FA0804 / [ed] Herta Steinkellner, Bryssel: COST , 2012, s. 47-47Konferensbidrag (Refereegranskat)
  • 43.
    Lindh, Ingrid
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Örebro Life Sci Ctr, Univ Örebro, Örebro, Sweden; Sch Sci & Technol, Univ Örebro, Örebro, Sweden.
    Bråve, Andreas
    Swedish Institute for Communicable Disease Control (SMI), Stockholm, Sweden.
    Hallengärd, David
    Dept Microbiol Tumor & Cell Biol, Karolinska Inst, Stockholm, Sweden.
    Hadad, Ronza
    Örebro universitet, Institutionen för naturvetenskap och teknik. Örebro Life Sci Ctr, Univ Örebro, Örebro, Sweden.
    Kalbina, Irina
    Örebro universitet, Institutionen för naturvetenskap och teknik. Örebro Life Sci Ctr, Univ Örebro, Örebro, Sweden.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik. Örebro Life Sci Ctr, Univ Örebro, Örebro, Sweden.
    Andersson, Sören
    Region Örebro län. Örebro Life Sci Ctr, Univ Örebro, Örebro, Sweden; Örebro University Hospital, Örebro, Sweden.
    Oral delivery of plant-derived HIV-1 p24 antigen in low doses shows a superior priming effect in mice compared to high doses2014Ingår i: Vaccine, ISSN 0264-410X, E-ISSN 1873-2518, Vol. 32, nr 20, s. 2288-2293Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During early infection with human immunodeficiency virus type 1 (HIV-1), there is a rapid depletion of CD4+ T-cells in the gut-associated lymphoid tissue (GALT) in the gastrointestinal tract. Therefore, immediate protection at these surfaces is of high priority for the development of an HIV-1 vaccine. Thus, transgenic plants expressing HIV-1 antigens, which are exposed to immune competent cells in the GALT during oral administration, can be interesting as potential vaccine candidates. In the present study, we used two HIV-1 p24 antigen-expressing transgenic plant systems, Arabidopsis thaliana and Daucus carota, in oral immunization experiments. Both transgenic plant systems showed a priming effect in mice and induced humoral immune responses, which could be detected as anti-p24-specific IgG in sera after an intramuscular p24 protein boost. Dose-dependent antigen analyses using transgenic Arabidopsis thaliana indicated that low p24 antigen doses were superior to high p24 antigen doses

  • 44.
    Lindh, Ingrid
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Bråve, Andreas
    Swedish Institute for Communicable Disease Control, The Public Health Agency of Sweden, Stockholm, Sweden.
    Hallengärd, David
    Swedish Institute for Communicable Disease Control, The Public Health Agency of Sweden, Stockholm, Sweden.
    Hadad, Ronza
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Andersson, Sören
    Örebro University Hospital, Örebro, Sweden.
    Oral delivery of transgenic plant-derived HIV-1 p24 antigen in low doses shows a superior priming effect in mice compared to higher doses2012Ingår i: Retrovirology, ISSN 1742-4690, E-ISSN 1742-4690, Vol. 9, nr Suppl. 2, artikel-id P336Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background

    The gut associated lymphoid tissue (GALT) includes around two thirds of the total lymphoid system. CD4+ T-cells in the GALT are a main target for HIV during primary infection. Thus, immunization targetting GALT is likely to be of importance for an effective vaccine strategy. Transgenic plants expressing HIV antigens can reach GALT conveniently. This system allows multiple boosts, has simple logistics (no cold chain, no injections) and large production capacity.

    Methods

    Three groups of mice were given extract from plant lines expressing HIV-1 p24 at (A) low level (20 ng/feeding); (B) high level (460 ng/feeding); (C) control (wild type, 0 ng). No adjuvant was included. The extracts were administered by gastric tube day 0, 14 and 28. On day 55 all mice were given an intramuscular (i.m.) boost with 10 micrograms of purified p24 antigen. Immune responses were determined by measurement of p24-antibodies in serum by ELISA.

    Results

    The mice immunized by the low dose plant line (A) showed a higher systemic immune response after i.m. boost compared to the high dose group (B). The w.t. controls (C) had undetectable p24-responses. The responses in group A were 3 to 10 times higher (ELISA OD values) than in group B. Pre-boost antibody responses were at background levels in all groups. Preliminary analyses indicate a predomninant Th1-type response (antigen-specific IgG2a higher than IgG1).

    Conclusion

    Simple and inexpensive means of vaccination are important in order to reach large numbers of people with effective vaccine regimens. The HIV-1 p24 low dose transgenic plant extracts given orally showed a superior priming effect in mice compared to the p24 high dose extracts. This could be an immunization method and route worth exploring further.

  • 45.
    Lindh, Ingrid
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bråve, Andreas
    Hallengärd, David
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Andersson, Sören
    Oral delivery of plant-derived HIV-1 p24 antigen in low doses shows a superior priming effect in mice compared to high dosesManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    During early infection with human immunodeficiency virus type 1 (HIV-1), there is a rapid depletion of CD4+ T-cells in the gut-associated lymphoid tissue (GALT) in the gastrointestinal tract. Therefore, immediate protection at these surfaces is of high priority for the development of an HIV-1 vaccine. Thus, transgenic plants expressing HIV-1 p24 antigen, which is released by immune competent cells in the GALT during oral administration, are interesting as potential vaccine candidates. In the present study, we used two HIV-1 p24 transgenic plant systems, Arabidopsis thaliana and Daucus carota, in oral immunization experiments. Both transgenic plant systems showed a priming effect in mice and induced humoral immune responses, which could be detected as anti-p24-specific-IgG in sera after an intramuscular p24 protein boost. Initial dose-dependent antigen analyses using transgenic Arabidopsis thaliana indicated that low p24 antigen doses were superior to high p24 antigen doses. No detectable levels of faecal IgA antibodies or cellular immune responses were observed.

  • 46.
    Lindh, Ingrid
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kalbina, Irina
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Hedberg, Sara Thulin
    Scherbak, Nikolai
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sävenstrand, Helena
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bråve, Andreas
    Hinkula, Jorma
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Andersson, Sören
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Feeding of mice with Arabidopsis thaliana expressing the HIV-1 subtype C p24 antigen gives rise to systemic immune responses2008Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 116, nr 11, s. 985-994Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Development of transgenic edible plants, to be used as production, storage and delivery systems for recombinant vaccine antigens, is a promising strategy to obtain cost effective vaccines against infectious diseases, not the least for use in developing countries. Therefore, we used Agrobacterium tumefaciens-mediated gene transfer to introduce the p24 gag gene encoding the nucleocapsid protein from HIV-1 subtype C into the Arabidopsis thaliana plant genome. Eighteen plant lines were confirmed positive for the p24 gene by PCR, four of these lines showed an apparent homozygous phenotype when grown on selective medium and these lines also showed transcription of the p24 gene into its corresponding mRNA. The mRNA in all four cases generated the p24 protein in plants, as verified by western blot analysis. The plants were shown to contain between 0.2 µg and 0.5 µg p24 protein per g of fresh tissue. Analysis of the localisation of the p24 protein showed that stem tissue contained the largest amount of protein, more than twice as much as leaf tissue, whereas no p24 protein was detected in roots. By using Southern blotting, we found that 4, 2-3, 2 and 1 T-DNA insertion events took place in the four lines 1, 2, 7, and 10, respectively. The genetic insertions of line 1 were stable from the T1 to the T4 generation and gave rise to the p24 protein in all cases, as verified by western blotting. In mice fed with fresh transgenic A. thaliana (line 10), anti-gag IgG was obtained in serum after a booster injection with recombinant p37Gag. No immune response was observed after equal booster injection of untreated mice or mice fed with A. thaliana WT plants.

  • 47.
    Lindh, Ingrid
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Wallin, Anita
    Evolutionsbiologiskt Centrum, Uppsala universitet.
    Kalbina, Irina
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sävenstrand, Helena
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Engström, Peter
    Uppsala Universitet.
    Andersson, Sören
    Smittskyddsinstitutet.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Production of the p24 capsid protein from HIV-1 subtype C in Arabidopsis thaliana and Daucus carota using an endoplasmic reticulum-directing SEKDEL sequence in protein expression constructs2009Ingår i: Protein Expression and Purification, ISSN 1046-5928, E-ISSN 1096-0279, Vol. 66, nr 1, s. 46-51Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An optimized gene expression construct was designed in order to increase the accumulation of the HIV-1 subtype C p24 protein in Arabidopsis thaliana and carrot (Daucus carota) plants. An ER retention signal was introduced into the genetic construct generating a p24 protein containing a SEKDEL amino acid sequence at its C-terminus. Mature A. thaliana plants and carrot cells were transformed using Agrobacterium tumefaciens carrying the improved pGreen0229/p24_SEKDEL vector. Several transgenic plant lines were obtained from both plant species by growth on selective medium and confirmed by PCR. Transformed lines were analyzed for p24 protein content by western blotting using anti-p24-specific antibodies and by Southern blotting to establish the number of copies of the insert in the plant nuclear genome. To estimate the accumulation levels of p24 protein in the plants, ELISA was run using soluble plant extracts. By comparing these results with our previous findings, the ER retention signal increased the level of p24 protein 5-fold in the Arabidopsis thaliana plants. In carrot taproot, the content of p24_SEKDEL protein was approximately half of that in Arabidopsis on a fresh weight basis and was stable in planta for several months. However, on a total soluble protein basis, carrots produced considerable higher levels of the p24_SEKDEL protein than Arabidopsis.

  • 48.
    Matxain, Jon M.
    et al.
    Euskal Herriko Unibertsitatea.
    Padro, Daniel
    Euskal Herriko Unibertsitatea.
    Ristilä, Mikael
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Eriksson, Leif A.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Evidence of High dot OH Radical Quenching Efficiency by Vitamin B-62009Ingår i: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 113, nr 29, s. 9629-9632Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Molecules acting as antioxidants capable of scavenging reactive oxygen species (ROS) are of the utmost importance in the living cell. The antioxidative properties of pyridoxine (vitamin B6) have recently been discovered. Previous theoretical calculations have shown a high reactivity of pyridoxine toward hydroxyl radicals, where the latter preferably abstract H from either carbon of the two methanol substituents (C8 or C9). In this study, we have explored the reactivity of pyridoxine toward further hydroxyl radicals, considering as the first step the H abstraction from either C8 or C9, also including addition reactions and cyclization. Many of the reactions display similar ΔG, and hence, the quenching of hydroxyl radicals by pyridoxine may undergo different pathways leading to a mix of products. In addition, we observe that pyridoxine, under high hydroxyl radical concentrations, may scavenge up to eight radicals, supporting its observed high antioxidant activity.

  • 49.
    Matxain, Jon M.
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Ristilä, Mikael
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Eriksson, Leif A.
    Örebro universitet, Institutionen för naturvetenskap.
    Theoretical study of the antioxidant properties of pyridoxine2006Ingår i: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 110, nr 48, s. 13068-13072Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Molecules acting as antioxidants capable of scavenging reactive oxygen species (ROS) are of utmost importance in the living cell. The antioxidative properties of pyridoxine (vitamin B6) have recently been discovered. In this study, we have analyzed the reactivity of pyridoxine toward the ROS .OH, .OOH, and .O2- at the density functional theory level (functionals B3LYP and MPW1B95). Two reaction types have been studied as follows: addition to the aromatic ring atoms and hydrogen/proton abstraction. Our results show that .OH is the most reactive species, while .OOH displays low reactivity and .O2- does not react at all with pyridoxine. The most exergonic reactions are those where .H is removed from the CH2OH groups or the ring-bound OH group and range from -33 to -39 kcal/mol. The most exergonic addition reactions occur by attacking the carbon atoms bonded to nitrogen but with an energy gain of only 6 kcal/mol.

  • 50.
    Matxain, Jon M
    et al.
    Örebro universitet, Institutionen för naturvetenskap.
    Ristilä, Mikael
    Örebro universitet, Institutionen för naturvetenskap.
    Strid, Åke
    Örebro universitet, Institutionen för naturvetenskap.
    Eriksson, Leif A
    Örebro universitet, Institutionen för naturvetenskap.
    Theoretical study of the reaction of vitamin B6 with 1O22007Ingår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 13, nr 16, s. 4636-42Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Singlet oxygen is known to cause oxidative stress in cells, leading to severe damage (e.g., lipid peroxidation, membrane degradation, mutagenic alterations to DNA, protein misfunctionality). Recently, pyridoxine has been discovered to be capable of quenching singlet oxygen, however, the mechanism of this reaction remains essentially unknown. In this work, we have investigated four sets of reactions: 1) 1,3-addition to a double bond connected to a hydrogen-carrying group,resulting in the formation of allylic hydroperoxides; 2) [p2+p2] 1,2-cycloaddition to an isolated double bond, resulting in the formation of 1,2-peroxides; 3) 1,4-cycloaddition to a system containing at least two conjugated double bonds, resulting in the formation of the so-called 1,4-peroxides;4) 1,4-addition to phenols and naphthols with the formation of hydroperoxide ketones. Thermodynamically, reaction 4 and the 6(9), 3(8), and 5(8) cases of reaction 1 are the most exergonic ones, with energies ranging from 16 to 18 kcalmol 1. Furthermore, reaction 4 shows the lowest barrier through the reaction path, and is predicted to be the preferred mechanism

    for the pyridoxine + singlet-oxygen reaction, which is in agreement with previous experimental results.

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