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Johansson, Magnus
Publications (10 of 30) Show all publications
Tran, P. T., Asghar, N., Karlsson, R., Karlsson, A., Johansson, M. & Melik, W. (2019). Identification and characterization of host proteins inducing the endoplasmic reticulum invagination during Flavivirus infection. In: Positive-Strand RNA Viuses: . Paper presented at Positive-Strand RNA Viuses, KILLARNEY, Co.Kerry, Ireland, June 9-13,2019 (pp. 280-280).
Open this publication in new window or tab >>Identification and characterization of host proteins inducing the endoplasmic reticulum invagination during Flavivirus infection
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2019 (English)In: Positive-Strand RNA Viuses, 2019, p. 280-280Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

When Flaviviruses infect host cells, they can induce invagination of endoplasmic reticulum (ER) membrane to form vesicle-like compartments. These unique structures are hypothetical to facilitate the viral replication by reducing diffusion of virus replication machinery and viral RNA, providing a scaffold to anchor the replication complex, and protecting viral RNA from host cell intrinsic surveillance. 

The rearrangements of ER membrane to form these replication compartments (RCs) require modifications in its lipid constituents or binding of proteins to the membrane. Flaviviruses, indeed, use their proteins to generate RCs. It has been implicated that both KUNV and DENV viral NS1, NS2A, NS4A, NS4B proteins could induce membrane remodelings. However, it is recondite whether host proteins can also participate in the formation and maintenance of RCs.

In this project, we aimed to identify and characterize of host proteins inducing RC generation during Flavivirus infections. We used A549 as a cell model, and mosquito-borne Zika and Kunjin virus, and tick-borne Langat virus as virus models. After virus infections, ER membranes were harvested using ultracentrifuge with a sucrose gradient. Proteins from these ERs were identified using mass spectrometry. We compared the differences between the ER proteomes of infected cells and non-infected cells to identify host candidate proteins that can cause the RC formation.  We are attempting to enrich the RC-containing fractions and identifying proteins here, which narrows the list of true candidate proteins. The candidate proteins then will be characterized by using molecular techniques such as gene knock down, overexpression, and microscopy techniques.

Keywords
Replication complex, Kunjin, Langat, Zika
National Category
Medical and Health Sciences Infectious Medicine
Research subject
Molecular Cellbiology; Biomedicine; Infectious Diseases
Identifiers
urn:nbn:se:oru:diva-76406 (URN)
Conference
Positive-Strand RNA Viuses, KILLARNEY, Co.Kerry, Ireland, June 9-13,2019
Funder
Knowledge Foundation, HÖG15 20150201
Available from: 2019-09-13 Created: 2019-09-13 Last updated: 2019-09-19
Johansson, M., Frelin, L., Maravelia, P., Asghar, N., Melik, W., Caro-Perez, N., . . . Sallberg, M. (2019). Immunogenicity of a New Flaviviral-Based DNA Launched Suicidal Replicon for Protective Vaccination Against Hepatitis C. Paper presented at 22nd Annual Meeting of the American-Society-of-Gene-and-Cell-Therapy (ASGCT), Washington, DC, USA, April 29 - May 2, 2019,. Molecular Therapy, 27(4), 139-139
Open this publication in new window or tab >>Immunogenicity of a New Flaviviral-Based DNA Launched Suicidal Replicon for Protective Vaccination Against Hepatitis C
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2019 (English)In: Molecular Therapy, ISSN 1525-0016, E-ISSN 1525-0024, Vol. 27, no 4, p. 139-139Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
Cell Press, 2019
National Category
Medical Genetics Microbiology in the medical area
Identifiers
urn:nbn:se:oru:diva-73957 (URN)10.1016/j.ymthe.2019.04.004 (DOI)000464381001137 ()
Conference
22nd Annual Meeting of the American-Society-of-Gene-and-Cell-Therapy (ASGCT), Washington, DC, USA, April 29 - May 2, 2019,
Available from: 2019-04-29 Created: 2019-04-29 Last updated: 2019-04-29Bibliographically approved
Asghar, N., Maravelia, P., Caro-Perez, N., Tarn, H., Melik, W., Pasetto, A., . . . Johansson, M. (2019). Immunogenicity of DNA launched suicidal flavivirus replicons for protective vaccination against hepatitis viruses. In: : . Paper presented at Positive-Strand RNA Viruses (E2), Killarney, Co. Kerry Ireland, June 9-13, 2019.
Open this publication in new window or tab >>Immunogenicity of DNA launched suicidal flavivirus replicons for protective vaccination against hepatitis viruses
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2019 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Chronic liver disease, resulting from Hepatitis B virus (HBV), Hepatitis D virus (HDV), or Hepatitis C virus (HCV) infections, contributes to a major health burden worldwide. Chronic infections with the hepatitis C virus (HCV) can be effectively cured by antivirals. However, as cured patients can be re-infected they lack protective immune responses. In addition, the relativelyhigh cost of the HCV treatment brings concerns about the accessibility, especially in the developing countries. Hence, there exists a need for cost effect vaccines with high efficiency to control and possibly eradicate Hepatitis viruses globally. The vaccine should induce either, or both, neutralizing antibodies and protective T cell responses. We therefore have developed DNA based flavivirus replicons as a potent delivery system that effectively prime HCV-specific T cell responses. We generated suicidal subgenomic DNA replicons of Tick-borne encephalitis virus (TBEV), Langat virus (LGTV), West-Nile virus (WNV), and Kunjinvirus (KUNV) expressing either a fusion protein between the HCV NS3/4A and a stork hepatitis B virus core or a vaccine candidate gene of HB/DV. Transfection experiments showed that the antigen expression by KUNV and WNV replicons was several folds higher than the antigen expression by standard DNA plasmid with CMV promoter. The immunogenicity of three suicidal flaviviral DNA replicons expressing HCV NS3/4A was tested in mice and compared to HCV NS3/4A expression by the standard DNA plasmid. The KUNV-HCV replicon was the best replicon-based immunogen with respect to priming of HCV NS3/4A-specific T cells as determined by ELISpot, dextramer staining, and polyfunctionality. Importantly, a mutant KUNV-HCV immunogen lacking replication failed to induce immune responses. Thus, the newly developed KUNV-based suicidal DNA launched replicon vaccine for HCV is a highly attractive candidate as a prophylactic vaccine against chronic hepatitis C. In addition, we are currently testing the immunogenicity of KUNV-HB/DV replicon in mice.

National Category
Medical and Health Sciences Infectious Medicine
Research subject
Infectious Diseases; Immunology
Identifiers
urn:nbn:se:oru:diva-76208 (URN)
Conference
Positive-Strand RNA Viruses (E2), Killarney, Co. Kerry Ireland, June 9-13, 2019
Funder
Knowledge Foundation, HÖG15 20150201
Available from: 2019-09-10 Created: 2019-09-10 Last updated: 2019-09-11Bibliographically approved
Asghar, N., Maravelia, P., Caro-Perez, N., Tran, P. T., Melik, W., Pasetto, A., . . . Johansson, M. (2019). Immunogenicity of DNA launched suicidal flavivirus replicons for protective vaccination against hepatitis viruses. In: : . Paper presented at 16th Smögen Summer Symposium on Virology, Smögen, Sweden, August 22-24, 2019.
Open this publication in new window or tab >>Immunogenicity of DNA launched suicidal flavivirus replicons for protective vaccination against hepatitis viruses
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2019 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Chronic liver disease, resulting from Hepatitis B virus (HBV), Hepatitis D virus (HDV), or Hepatitis C virus (HCV) infections, contributes to a major health burden worldwide. Chronic infections with the hepatitis C virus (HCV) can be effectively cured by antivirals. However, as cured patients can be re-infected they lack protective immune responses. In addition, the relativelyhigh cost of the HCV treatment brings concerns about the accessibility, especially in the developing countries. Hence, there exists a need for cost effect vaccines with high efficiency to control and possibly eradicate Hepatitis viruses globally. The vaccine should induce either, or both, neutralizing antibodies and protective T cell responses. We therefore have developed DNA based flavivirus replicons as a potent delivery system that effectively prime HCV-specific T cell responses. We generated suicidal subgenomic DNA replicons of Tick-borne encephalitis virus (TBEV), Langat virus (LGTV), West-Nile virus (WNV), and Kunjinvirus (KUNV) expressing either a fusion protein between the HCV NS3/4A and a stork hepatitis B virus core or a vaccine candidate gene of HB/DV. Transfection experiments showed that the antigen expression by KUNV and WNV replicons was several folds higher than the antigen expression by standard DNA plasmid with CMV promoter. The immunogenicity of three suicidal flaviviral DNA replicons expressing HCV NS3/4A was tested in mice and compared to HCV NS3/4A expression by the standard DNA plasmid. The KUNV-HCV replicon was the best replicon-based immunogen with respect to priming of HCV NS3/4A-specific T cells as determined by ELISpot, dextramer staining, and polyfunctionality. Importantly, a mutant KUNV-HCV immunogen lacking replication failed to induce immune responses. Thus, the newly developed KUNV-based suicidal DNA launched replicon vaccine for HCV is a highly attractive candidate as a prophylactic vaccine against chronic hepatitis C. In addition, we are currently testing the immunogenicity of KUNV-HB/DV replicon in mice.

National Category
Medical and Health Sciences Immunology Infectious Medicine
Research subject
Molecular Biology; Infectious Diseases; Immunology
Identifiers
urn:nbn:se:oru:diva-76634 (URN)
Conference
16th Smögen Summer Symposium on Virology, Smögen, Sweden, August 22-24, 2019
Available from: 2019-09-20 Created: 2019-09-20 Last updated: 2019-09-23Bibliographically approved
Tran, P. T., Asghar, N., Karlsson, R., Karlsson, A., Johansson, M. & Melik, W. (2019). Screening of host proteins interacting with Kunjin, Langat, Zika replication complex. In: Positive-Strand Rna Viuses: . Paper presented at Positive-Strand RNA Viuses, KILLARNEY, Co.Kerry, Ireland, June 9-13,2019.
Open this publication in new window or tab >>Screening of host proteins interacting with Kunjin, Langat, Zika replication complex
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2019 (English)In: Positive-Strand Rna Viuses, 2019Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

When Flaviviruses infect host cells, they can induce invagination of endoplasmic reticulum (ER) membrane to form vesicle-like compartments. These unique structures are hypothetical to facilitate the viral replication by reducing diffusion of virus replication machinery and viral RNA, providing a scaffold to anchor the replication complex, and protecting viral RNA from host cell intrinsic surveillance. 

The rearrangements of ER membrane to form these replication compartments (RCs) require modifications in its lipid constituents or binding of proteins to the membrane. Flaviviruses, indeed, use their proteins to generate RCs. It has been implicated that both KUNV and DENV viral NS1, NS2A, NS4A, NS4B proteins could induce membrane remodelings. However, it is recondite whether host proteins can also participate in the formation and maintenance of RCs.

In this project, we aimed to identify and characterize of host proteins inducing RC generation during Flavivirus infections. We used A549 as a cell model, and mosquito-borne Zika and Kunjin virus, and tick-borne Langat virus as virus models. After virus infections, ER membranes were harvested using ultracentrifuge with a sucrose gradient. Proteins from these ERs were identified using mass spectrometry. We compared the differences between the ER proteomes of infected cells and non-infected cells to identify host candidate proteins that can cause the RC formation.  We are attempting to enrich the RC-containing fractions and identifying proteins here, which narrows the list of true candidate proteins. The candidate proteins then will be characterized by using molecular techniques such as gene knock down, overexpression, and microscopy techniques.

Keywords
Replication complex, Kunjin, Langat, Zika
National Category
Medical and Health Sciences Infectious Medicine
Research subject
Molecular Cellbiology; Biomedicine; Infectious Diseases
Identifiers
urn:nbn:se:oru:diva-76400 (URN)
Conference
Positive-Strand RNA Viuses, KILLARNEY, Co.Kerry, Ireland, June 9-13,2019
Funder
Knowledge Foundation, HÖG15 20150201
Available from: 2019-09-13 Created: 2019-09-13 Last updated: 2019-09-13Bibliographically approved
Tran, P. T., Asghar, N., Karlsson, A., Karlsson, R., Johansson, M. & Melik, W. (2019). Screening of host proteins interacting with Kunjin, Langat, Zikareplication complex. In: 16th Smögen Summer Symposium on Virology: . Paper presented at 16th Smögen Summer Symposium on Virology, Smögen, Sweden, August 22-24, 2019.
Open this publication in new window or tab >>Screening of host proteins interacting with Kunjin, Langat, Zikareplication complex
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2019 (English)In: 16th Smögen Summer Symposium on Virology, 2019Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

During infection and eclipse time, Flaviviruses induce invagination of the endoplasmic reticulum (ER) membrane to form compartments, protecting their viral replication complex. The rearrangements of ER membrane require modifications in ER membrane lipid constituents or binding of proteins to bend the membrane. Indeed, it has been implicated that both KUNV and DENV NS1, NS2A, NS4A, NS4B proteins could induce membrane remodelings. However, it is not well known whether host proteins can also participate in the formation and maintenance of these compartments.In this project, we aimed to identify host proteins interacting with Kunjin, Langat, Zika replication complex. These proteins may function for ER invagination during Flavivirus infection. We used human adenocarcinoma epithelial A549 cells as a cell model, mosquito-borne Zika, Kunjin virus, and tick-borne Langat virus as virus models. After virus infections, the ER membranes from infected and non-infected cells were harvested using ultracentrifuge with a sucrose gradient. Proteins from these ERs were identified using mass spectrometry. We compared the differences between the ER proteomes to identify host candidate proteins that can cause the RC formation. To narrows the list of true candidate proteins, we attempted to enrich the RC-containing fractions by doing co-immuno precipitation. We are doing TMT-MS to identify and quantify the host proteins from Co-IP elutions. The functions of these proteins will be characterized by using molecular techniques.

Keywords
Replication complex, host cell, Westnile, Langat, Zika
National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Research subject
Biomedicine; Molecular Cellbiology; Infectious Diseases
Identifiers
urn:nbn:se:oru:diva-76402 (URN)
Conference
16th Smögen Summer Symposium on Virology, Smögen, Sweden, August 22-24, 2019
Funder
Knowledge Foundation, HÖG15 20150201
Available from: 2019-09-13 Created: 2019-09-13 Last updated: 2019-09-16Bibliographically approved
Asghar, N., Gunaltay, S., Tran, P. T., Melik, W., Höglund, U., Johansson, C., . . . Johansson, M. (2018). DNA launched suicidal flaviviruses as therapeutic vaccine candidates. In: : . Paper presented at 15th Smögen Summer Symposium on Virology, Smögen, Sweden, August 23-25, 2018.
Open this publication in new window or tab >>DNA launched suicidal flaviviruses as therapeutic vaccine candidates
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2018 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Chronic liver disease, resulting from Hepatitis B virus (HBV), Hepatitis D virus (HDV), or Hepatitis C virus (HCV) infections, contributes to a major health burden worldwide. The relativelyhigh cost of the HCV treatment brings concerns about the accessibility, especially in the developing countries. Hence, there exists a need for cost effect interventions with high efficiency. We aim to develop therapeutic vaccine candidates against HBV, HCV and HDV using DNA based subgenomic flavivirus replicons as a delivery system. Tick-borne encephalitis virus (TBEV), Langat virus (LGTV), West-Nile virus (WNV), or Kunjinvirus (KUNV) replicon with firefly luciferase geneas a reporter were expressed and characterized in cell culture studies. WNV and KUNV replicons showed significantly higher replication compared to their respective negative controls with unfunctional viral RNA dependent RNA polymerase. KUNV and WNV replicons were chosen for cloning the HCV or HB/DV vaccine candidate gene by replacing luciferasegene. Owing to the self-replicating trait of the flavivirus subgenomic replicons, Western blotting demonstrated that the antigen expression by KUNV and WNV replicons was several folds higher than the positive control. These results suggest that DNA based KUNV and WNV replicons may function as carriers for the hepatitis vaccine candidate genes, and these replicons are currently used for in vivostudies in animal models.

National Category
Medical and Health Sciences Infectious Medicine Immunology
Research subject
Immunology; Infectious Diseases
Identifiers
urn:nbn:se:oru:diva-76632 (URN)
Conference
15th Smögen Summer Symposium on Virology, Smögen, Sweden, August 23-25, 2018
Available from: 2019-09-20 Created: 2019-09-20 Last updated: 2019-09-23Bibliographically approved
Asghar, N., Pettersson, J.-O. H., Dinnetz, P., Andreassen, Å. & Johansson, M. (2017). Deep sequencing analysis of tick-borne encephalitis virus from questing ticks at natural foci reveals similarities between quasispecies pools of the virus. Journal of General Virology, 98(3), 413-421
Open this publication in new window or tab >>Deep sequencing analysis of tick-borne encephalitis virus from questing ticks at natural foci reveals similarities between quasispecies pools of the virus
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2017 (English)In: Journal of General Virology, ISSN 0022-1317, E-ISSN 1465-2099, Vol. 98, no 3, p. 413-421Article in journal (Refereed) Published
Abstract [en]

Every year, tick-borne encephalitis virus (TBEV) causes severe central nervous system infection in 10,000 to 15,000 people in Europe and Asia. TBEV is maintained in the environment by an enzootic cycle that requires a tick vector and a vertebrate host, and the adaptation of TBEV to vertebrate and invertebrate environments is essential for TBEV persistence in nature. This adaptation is facilitated by the error-prone nature of the virus' RNA-dependent RNA polymerase that generates genetically distinct virus variants called quasispecies. TBEV shows a focal geographical distribution pattern where each focus represents a TBEV hotspot. Here we sequenced and characterized two TBEV genomes, JP-296 and JP-554, from questing Ixodes ricinus ticks at a TBEV focus in central Sweden. Phylogenetic analysis showed geographical clustering among the newly sequenced strains and three previously sequenced Scandinavian strains, Toro-2003, Saringe-2009, and Mandal-2009, which originated from same ancestor. Among these five Scandinavian TBEV strains, only Mandal-2009 showed a large deletion within the 3´ non-coding region (NCR) similar to the highly virulent TBEV strain Hypr. Deep sequencing of JP-296, JP-554, and Mandal-2009 revealed significantly high quasispecies diversity for JP-296 and JP-554, with intact 3´NCRs, compared to the low diversity in Mandal-2009, with a truncated 3´NCR. SNP analysis showed that 40% of the SNPs were common between quasispecies populations of JP-296 and JP-554, indicating a putative mechanism for how TBEV persists and is maintained within its natural foci.

Place, publisher, year, edition, pages
Microbiology Society, 2017
Keywords
Ixodes ricinus; natural foci; non-coding region; quasispecies; Scandinavia; tick-borne encephalitis virus
National Category
Microbiology in the medical area
Research subject
Microbiology
Identifiers
urn:nbn:se:oru:diva-56063 (URN)10.1099/jgv.0.000704 (DOI)000399235600013 ()28073402 (PubMedID)2-s2.0-85016952345 (Scopus ID)
Funder
Swedish Research Council Formas, 201601400 2015-710
Note

Funding Agencies:

INTERREG-OKS Project ScandTick Innovation  ID 20200422

Foundation for Baltic and East European Studies  1330/42/2010

Available from: 2017-03-06 Created: 2017-03-06 Last updated: 2018-07-30Bibliographically approved
Johansson, M. (2017). Development of an edible Tick-borne encephalitis vaccine. In: : . Paper presented at SNÄFF (Svenska nätverket för fästing forskare) 2017, Varberg, Sweden, 3-5 maj 2017.
Open this publication in new window or tab >>Development of an edible Tick-borne encephalitis vaccine
2017 (English)Conference paper, Oral presentation only (Other academic)
National Category
Medical and Health Sciences Microbiology in the medical area
Research subject
Biomedicine
Identifiers
urn:nbn:se:oru:diva-62804 (URN)
Conference
SNÄFF (Svenska nätverket för fästing forskare) 2017, Varberg, Sweden, 3-5 maj 2017
Projects
ScandTick Innovation
Available from: 2017-11-24 Created: 2017-11-24 Last updated: 2018-01-13Bibliographically approved
Asghar, N., Lee, Y.-P., Nilsson, E., Lindqvist, R., Melik, W., Kröger, A., . . . Johansson, M. (2016). The role of the poly(A) tract in the replication and virulence of tick-borne encephalitis virus. Scientific Reports, 6, Article ID 39265.
Open this publication in new window or tab >>The role of the poly(A) tract in the replication and virulence of tick-borne encephalitis virus
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2016 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 39265Article in journal (Refereed) Published
Abstract [en]

The tick-borne encephalitis virus (TBEV) is a flavivirus transmitted to humans, usually via tick bites. The virus causes tick-borne encephalitis (TBE) in humans, and symptoms range from mild flu-like symptoms to severe and long-lasting sequelae, including permanent brain damage. It has been suggested that within the population of viruses transmitted to the mammalian host, quasispecies with neurotropic properties might become dominant in the host resulting in neurological symptoms. We previously demonstrated the existence of TBEV variants with variable poly(A) tracts within a single blood-fed tick. To characterize the role of the poly(A) tract in TBEV replication and virulence, we generated infectious clones of Torö-2003 with the wild-type (A)3C(A)6 sequence (Torö-6A) or with a modified (A)3C(A)38 sequence (Torö-38A). Torö-38A replicated poorly compared to Torö-6A in cell culture, but Torö-38A was more virulent than Torö-6A in a mouse model of TBE. Next-generation sequencing of TBEV genomes after passaging in cell culture and/or mouse brain revealed mutations in specific genomic regions and the presence of quasispecies that might contribute to the observed differences in virulence. These data suggest a role for quasispecies development within the poly(A) tract as a virulence determinant for TBEV in mice.

Place, publisher, year, edition, pages
London, United Kingdom: Nature Publishing Group, 2016
National Category
Microbiology
Identifiers
urn:nbn:se:oru:diva-54097 (URN)10.1038/srep39265 (DOI)000389971500001 ()27982069 (PubMedID)2-s2.0-85006377174 (Scopus ID)
Funder
Knowledge FoundationSwedish Research CouncilSwedish Foundation for Strategic Research
Note

Funding Agencies:

Foundation for Baltic and East European Studies

MIMS

Umeå Center for Microbial Research (UCMR)

Available from: 2016-12-21 Created: 2016-12-20 Last updated: 2018-07-23Bibliographically approved
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