scholarly journals Removal of the C6 vaccinia virus interferon-β inhibitor in the hepatitis C vaccine candidate MVA-HCV elicited in mice high immunogenicity in spite of reduced host gene expression

2018 ◽  
Author(s):  
María Q. Marín ◽  
Patricia Pérez ◽  
Carmen E. Gómez ◽  
Carlos Óscar S. Sorzano ◽  
Mariano Esteban ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Cell ◽  
Global Health ◽  
Vaccinia Virus ◽  
Vaccine Candidate ◽  
Vaccine Candidates ◽  
Modified Vaccinia Virus Ankara ◽  
Global Health Problem

ABSTRACTHepatitis C virus (HCV) represents a major global health problem for which a vaccine is not available. MVA-HCV is a unique HCV vaccine candidate based in the modified vaccinia virus Ankara (MVA) vector expressing the nearly full-length genome of HCV genotype 1a that elicits broad and polyfunctional CD8+ T-cell responses in mice. With the aim to improve the immune response of MVA-HCV and due to the importance of interferon (IFN) in HCV infection, we deleted in MVA-HCV the vaccinia virus (VACV) C6L gene, encoding an inhibitor of IFN-β that prevents activation of the transcription factors IRF3 and IRF7. The resulting vaccine candidate (MVA-HCV ΔC6L) expresses all HCV antigens and deletion of C6L had no effect on viral growth in permissive chicken cells. In human monocyte-derived dendritic cells, infection with MVA-HCV ΔC6L triggered severe down-regulation of IFN-β, IFN-β-induced genes and cytokines similarly to MVA-HCV, as defined by real-time PCR and microarray analysis. In infected mice both vectors had a similar profile of recruited immune cells and induced comparable levels of adaptive and memory HCV-specific CD8+ T-cells, mainly against p7+NS2 and NS3 HCV proteins, with a T cell effector memory (TEM) phenotype. Furthermore, antibodies against E2 were also induced. Overall, our findings showed that while these vectors had a profound inhibitory effect on gene expression of the host, they strongly elicited CD8+ T cell and humoral responses against HCV antigens. These observations add support to the consideration of these vectors as potential vaccine candidates against HCV.IMPORTANCEHepatitis C virus represents a global health problem with 71 million of people infected worldwide. While direct-acting antivirals agents can cure hepatitis C virus infection in most of patients, their high cost and the emergence of drug resistant variants make them not a feasible and affordable strategy to eradicate the virus. Therefore, a vaccine is an urgent goal that requires efforts in understanding the correlates of protection for hepatitis C virus clearance. Poxvirus vectors, in particular the attenuated modified vaccinia virus Ankara, are ideal as vaccine candidates due to their ability to induce both T and B cell immune responses against heterologous antigens and protection against a wide spectrum of pathogens. Here we describe the generation, genetics and immunogenicity elicited by MVA-HCV ΔC6L, a novel vaccine candidate for hepatitis C virus that expresses nearly all of hepatitis C proteins but lacks an IFN-β inhibitor, the C6 vaccinia virus protein.

scholarly journals Removal of the C6 Vaccinia Virus Interferon-β Inhibitor in the Hepatitis C Vaccine Candidate MVA-HCV Elicited in Mice High Immunogenicity in Spite of Reduced Host Gene Expression

Viruses ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 414 ◽  
Author(s):  
María Q. Marín ◽  
Patricia Pérez ◽  
Carmen E. Gómez ◽  
Carlos Óscar S. Sorzano ◽  
Mariano Esteban ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hepatitis C ◽  
T Cell ◽  
Vaccinia Virus ◽  
Vaccine Candidate ◽  
Human Monocyte ◽  
Cd8 T Cell ◽  
Inhibitory Effect ◽  
Effector Memory ◽  
Modified Vaccinia Virus Ankara

Hepatitis C virus (HCV) represents a major global health problem for which a vaccine is not available. Modified vaccinia virus Ankara (MVA)-HCV is a unique HCV vaccine candidate based in the modified vaccinia virus Ankara (MVA) vector expressing the nearly full-length genome of HCV genotype 1a that elicits CD8+ T-cell responses in mice. With the aim to improve the immune response of MVA-HCV and because of the importance of interferon (IFN) in HCV infection, we deleted in MVA-HCV the vaccinia virus (VACV) C6L gene, encoding an inhibitor of IFN-β that prevents activation of the interferon regulatory factors 3 and 7 (IRF3 and IRF7). The resulting vaccine candidate (MVA-HCV ΔC6L) expresses all HCV antigens and deletion of C6L had no effect on viral growth in permissive chicken cells. In human monocyte-derived dendritic cells, infection with MVA-HCV ΔC6L triggered severe down-regulation of IFN-β, IFN-β-induced genes, and cytokines in a manner similar to MVA-HCV, as defined by real-time polymerase chain reaction (PCR) and microarray analysis. In infected mice, both vectors had a similar profile of recruited immune cells and induced comparable levels of adaptive and memory HCV-specific CD8+ T-cells, mainly against p7 + NS2 and NS3 HCV proteins, with a T cell effector memory (TEM) phenotype. Furthermore, antibodies against E2 were also induced. Overall, our findings showed that while these vectors had a profound inhibitory effect on gene expression of the host, they strongly elicited CD8+ T cell and humoral responses against HCV antigens and to the virus vector. These observations add support to the consideration of these vectors as potential vaccine candidates against HCV.

scholarly journals Potent Anti-hepatitis C Virus (HCV) T Cell Immune Responses Induced in Mice Vaccinated with DNA-Launched RNA Replicons and Modified Vaccinia Virus Ankara-HCV

2019 ◽  
Vol 93 (7) ◽  
Author(s):  
María Q. Marín ◽  
Patricia Pérez ◽  
Karl Ljungberg ◽  
Carlos Óscar S. Sorzano ◽  
Carmen E. Gómez ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Cell ◽  
Immune Responses ◽  
Vaccinia Virus ◽  
Cell Responses ◽  
Immunization Protocol ◽  
Modified Vaccinia Virus Ankara ◽  
Boost Immunization ◽  
T Cell Immune Responses

ABSTRACTHepatitis C is a liver disease caused by the hepatitis C virus (HCV) affecting 71 million people worldwide with no licensed vaccines that prevent infection. Here, we have generated four novel alphavirus-based DNA-launched self-amplifying RNA replicon (DREP) vaccines expressing either structural core-E1-E2 or nonstructural p7-NS2-NS3 HCV proteins of genotype 1a placed under the control of an alphavirus promoter, with or without an alphaviral translational enhancer (grouped as DREP-HCV or DREP-e-HCV, respectively). DREP vectors are known to induce cross-priming and further stimulation of immune responses through apoptosis, and here we demonstrate that they efficiently trigger apoptosis-related proteins in transfected cells. Immunization of mice with the DREP vaccines as the priming immunization followed by a heterologous boost with a recombinant modified vaccinia virus Ankara (MVA) vector expressing the nearly full-length genome of HCV (MVA-HCV) induced potent and long-lasting HCV-specific CD4+and CD8+T cell immune responses that were significantly stronger than those of a homologous MVA-HCV prime/boost immunization, with the DREP-e-HCV/MVA-HCV combination the most immunogenic regimen. HCV-specific CD4+and CD8+T cell responses were highly polyfunctional, had an effector memory phenotype, and were mainly directed against E1-E2 and NS2-NS3, respectively. Additionally, DREP/MVA-HCV immunization regimens induced higher antibody levels against HCV E2 protein than homologous MVA-HCV immunization. Collectively, these results provided an immunization protocol against HCV by inducing high levels of HCV-specific T cell responses as well as humoral responses. These findings reinforce the combined use of DREP-based vectors and MVA-HCV as promising prophylactic and therapeutic vaccines against HCV.IMPORTANCEHCV represents a global health problem as more than 71 million people are chronically infected worldwide. Direct-acting antiviral agents can cure HCV infection in most patients, but due to the high cost of these agents and the emergence of resistant mutants, they do not represent a feasible and affordable strategy to eradicate the virus. Therefore, a vaccine is an urgent goal that requires efforts to understand the correlates of protection for HCV clearance. Here, we describe for the first time the generation of novel vaccines against HCV based on alphavirus DNA replicons expressing HCV antigens. We demonstrate that potent T cell immune responses, as well as humoral immune responses, against HCV can be achieved in mice by using a combined heterologous prime/boost immunization protocol consisting of the administration of alphavirus replicon DNA vectors as the priming immunization followed by a boost with a recombinant modified vaccinia virus Ankara vector expressing HCV antigens.

scholarly journals Antisense Oligonucleotide Inhibition of Hepatitis C Virus (HCV) Gene Expression in Livers of Mice Infected with an HCV-Vaccinia Virus Recombinant

1999 ◽  
Vol 43 (2) ◽  
pp. 347-353 ◽  
Author(s):  
Hong Zhang ◽  
Ronnie Hanecak ◽  
Vickie Brown-Driver ◽  
Raana Azad ◽  
Boyd Conklin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Animal Model ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Vaccinia Virus ◽  
Antisense Oligonucleotides ◽  
Small Animal ◽  
Initiation Codon ◽  
Small Animal Model ◽  
Recombinant Vaccinia

ABSTRACT Hepatitis C virus (HCV) is the major cause of non-A, non-B hepatitis worldwide. Current treatments are not curative for most infected individuals, and there is an urgent need for both novel therapeutic agents and small-animal models which can be used to evaluate candidate drugs. A small-animal model of HCV gene expression was developed with recombinant vaccinia virus vectors. VHCV-IRES (internal ribosome entry site) is a recombinant vaccinia viral vector containing the HCV 5′ nontranslated region (5′-NTR) and a portion of the HCV core coding region fused to the firefly luciferase gene. Intraperitoneal injection of VHCV-IRES produced high levels of luciferase activity in the livers of BALB/c mice. Antisense oligonucleotides complementary to the HCV 5′-NTR and translation initiation codon regions were then evaluated for their effects on the expression of these target HCV sequences in BALB/c mice infected with the vaccinia virus vector. Treatment of VHCV-IRES-infected mice with 20-base phosphorothioate oligonucleotides complementary to the sequence surrounding the HCV initiation codon (nucleotides 330 to 349) specifically reduced luciferase expression in the livers in a dose-dependent manner. Inhibition of HCV reporter gene expression in this small-animal model suggests that antisense oligonucleotides may provide a novel therapy for treatment of chronic HCV infection.

scholarly journals COVID-19 vaccine candidates based on modified vaccinia virus Ankara expressing the SARS-CoV-2 spike induce robust T- and B-cell immune responses and full efficacy in mice

2021 ◽  
Author(s):  
Juan García-Arriaza ◽  
Urtzi Garaigorta ◽  
Patricia Pérez ◽  
Adrián Lázaro-Frías ◽  
Carmen Zamora ◽  
...  
Keyword(s):  
T Cell ◽  
Animal Models ◽  
Vaccinia Virus ◽  
Virus Replication ◽  
T Cell Responses ◽  
Effector Memory ◽  
S Protein ◽  
Vaccine Candidates ◽  
Cell Responses ◽  
Modified Vaccinia Virus Ankara

Vaccines against SARS-CoV-2, the causative agent of the COVID-19 pandemic, are urgently needed. We developed two COVID-19 vaccines based on modified vaccinia virus Ankara (MVA) vectors expressing the entire SARS-CoV-2 spike (S) protein (MVA-CoV2-S); their immunogenicity was evaluated in mice using DNA/MVA or MVA/MVA prime/boost immunizations. Both vaccines induced robust, broad and polyfunctional S-specific CD4+ (mainly Th1) and CD8+ T-cell responses, with a T effector memory phenotype. DNA/MVA immunizations elicited higher T-cell responses. All vaccine regimens triggered high titers of IgG antibodies specific for the S, as well as for the receptor-binding domain; the predominance of the IgG2c isotype was indicative of Th1 immunity. Notably, serum samples from vaccinated mice neutralized SARS-CoV-2 in cell cultures, and those from MVA/MVA immunizations showed a higher neutralizing capacity. Remarkably, one or two doses of MVA-CoV2-S protect humanized K18-hACE2 mice from a lethal dose of SARS-CoV-2. In addition, two doses of MVA-CoV2-S confer full inhibition of virus replication in the lungs. These results demonstrate the robust immunogenicity and full efficacy of MVA-based COVID-19 vaccines in animal models and support its translation to the clinic. IMPORTANCE The continuous dissemination of the novel emerging SARS-CoV-2 virus, with more than 78 million infected cases worldwide and higher than 1,700,000 deaths as of December 23, 2020, highlights the urgent need for the development of novel vaccines against COVID-19. With this aim, we have developed novel vaccine candidates based on the poxvirus modified vaccinia virus Ankara (MVA) strain expressing the full-length SARS-CoV-2 spike (S) protein, and we have evaluated their immunogenicity in mice using DNA/MVA or MVA/MVA prime/boost immunization protocols. The results showed the induction of a potent S-specific T-cell response and high titers of neutralizing antibodies. Remarkably, humanized K18-hACE2 mice immunized with one or two doses of the MVA-based vaccine were 100% protected from SARS-CoV-2 lethality. Moreover, two doses of the vaccine prevented virus replication in lungs. Our findings prove the robust immunogenicity and efficacy of MVA-based COVID-19 vaccines in animal models and support its translation to the clinic.

scholarly journals Hepatitis C Genotype 1 Mosaic Vaccines Are Immunogenic in Mice and Induce Stronger T-Cell Responses than Natural Strains

2012 ◽  
Vol 20 (2) ◽  
pp. 302-305 ◽  
Author(s):  
Karina Yusim ◽  
Rebecca Dilan ◽  
Erica Borducchi ◽  
Kelly Stanley ◽  
Elena Giorgi ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Cell ◽  
T Cell Responses ◽  
Genotype 1 ◽  
Vaccine Candidates ◽  
Cell Responses ◽  
Hcv Genotype 1 ◽  
Mosaic Protein ◽  
Natural Strains

ABSTRACTDespite improved hepatitis C virus (HCV) treatments, vaccines remain an effective and economic option for curtailing the epidemic. Mosaic protein HCV genotype 1 vaccine candidates designed to address HCV diversity were immunogenic in mice. They elicited stronger T-cell responses to NS3-NS4a and E1-E2 proteins than did natural strains, as assessed with vaccine-matched peptides.

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