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

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.

Download Full-text

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

10.1101/330902 ◽

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.

Download Full-text

High, Broad, Polyfunctional, and Durable T Cell Immune Responses Induced in Mice by a Novel Hepatitis C Virus (HCV) Vaccine Candidate (MVA-HCV) Based on Modified Vaccinia Virus Ankara Expressing the Nearly Full-Length HCV Genome

Journal of Virology ◽

10.1128/jvi.03246-12 ◽

2013 ◽

Vol 87 (13) ◽

pp. 7282-7300 ◽

Cited By ~ 24

Author(s):

C. E. Gomez ◽

B. Perdiguero ◽

M. V. Cepeda ◽

L. Mingorance ◽

J. Garcia-Arriaza ◽

...

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

T Cell ◽

Immune Responses ◽

Vaccinia Virus ◽

Vaccine Candidate ◽

Full Length ◽

Modified Vaccinia Virus Ankara ◽

T Cell Immune Responses

Download Full-text

Immediate-Early Expression of a Recombinant Antigen by Modified Vaccinia Virus Ankara Breaks the Immunodominance of Strong Vector-Specific B8R Antigen in Acute and Memory CD8 T-Cell Responses

Journal of Virology ◽

10.1128/jvi.00604-10 ◽

2010 ◽

Vol 84 (17) ◽

pp. 8743-8752 ◽

Cited By ~ 33

Author(s):

Karen Baur ◽

Kay Brinkmann ◽

Marc Schweneker ◽

Juliane Pätzold ◽

Christine Meisinger-Henschel ◽

...

Keyword(s):

T Cell ◽

Vaccinia Virus ◽

T Cell Responses ◽

Cd8 T Cell ◽

Immediate Early ◽

Egfp Expression ◽

Cell Responses ◽

Modified Vaccinia Virus Ankara ◽

Memory Cd8 T Cell ◽

Early Late

ABSTRACT Efficient T-cell responses against recombinant antigens expressed by vaccinia virus vectors require expression of these antigens in the early phase of the virus replication cycle. The kinetics of recombinant gene expression in poxviruses are largely determined by the promoter chosen. We used the highly attenuated modified vaccinia virus Ankara (MVA) to determine the role of promoters in the induction of CD8 T-cell responses. We constructed MVA recombinants expressing either enhanced green fluorescent protein (EGFP) or chicken ovalbumin (OVA), each under the control of a hybrid early-late promoter (pHyb) containing five copies of a strong early element or the well-known early-late p7.5 or pS promoter for comparison. In primary or cultured cells, EGFP expression under the control of pHyb was detected within 30 min, as an immediate-early protein, and remained higher over the first 6 h of infection than p7.5- or pS-driven EGFP expression. Repeated immunizations of mice with recombinant MVA expressing OVA under the control of the pHyb promoter led to superior acute and memory CD8 T-cell responses compared to those to p7.5- and pS-driven OVA. Moreover, OVA expressed under the control of pHyb replaced the MVA-derived B8R protein as the immunodominant CD8 T-cell antigen after three or more immunizations. This is the first demonstration of an immediate-early neoantigen expressed by a poxviral vector resulting in superior induction of neoantigen-specific CD8 T-cell responses.

Download Full-text

Novel Recombinant Mycobacterium bovis BCG, Ovine Atadenovirus, and Modified Vaccinia Virus Ankara Vaccines Combine To Induce Robust Human Immunodeficiency Virus-Specific CD4 and CD8 T-Cell Responses in Rhesus Macaques

Journal of Virology ◽

10.1128/jvi.02607-09 ◽

2010 ◽

Vol 84 (12) ◽

pp. 5898-5908 ◽

Cited By ~ 19

Author(s):

Maximillian Rosario ◽

Richard Hopkins ◽

John Fulkerson ◽

Nicola Borthwick ◽

Máire F. Quigley ◽

...

Keyword(s):

T Cell ◽

Vaccinia Virus ◽

Mycobacterium Bovis ◽

Ex Vivo ◽

Rhesus Macaques ◽

T Cell Responses ◽

Cd8 T Cell ◽

Cell Responses ◽

Modified Vaccinia Virus Ankara ◽

Hiv 1

ABSTRACT Mycobacterium bovis bacillus Calmette-Guérin (BCG), which elicits a degree of protective immunity against tuberculosis, is the most widely used vaccine in the world. Due to its persistence and immunogenicity, BCG has been proposed as a vector for vaccines against other infections, including HIV-1. BCG has a very good safety record, although it can cause disseminated disease in immunocompromised individuals. Here, we constructed a recombinant BCG vector expressing HIV-1 clade A-derived immunogen HIVA using the recently described safer and more immunogenic BCG strain AERAS-401 as the parental mycobacterium. Using routine ex vivo T-cell assays, BCG.HIVA401 as a stand-alone vaccine induced undetectable and weak CD8 T-cell responses in BALB/c mice and rhesus macaques, respectively. However, when BCG.HIVA401 was used as a priming component in heterologous vaccination regimens together with recombinant modified vaccinia virus Ankara-vectored MVA.HIVA and ovine atadenovirus-vectored OAdV.HIVA vaccines, robust HIV-1-specific T-cell responses were elicited. These high-frequency T-cell responses were broadly directed and capable of proliferation in response to recall antigen. Furthermore, multiple antigen-specific T-cell clonotypes were efficiently recruited into the memory pool. These desirable features are thought to be associated with good control of HIV-1 infection. In addition, strong and persistent T-cell responses specific for the BCG-derived purified protein derivative (PPD) antigen were induced. This work is the first demonstration of immunogenicity for two novel vaccine vectors and the corresponding candidate HIV-1 vaccines BCG.HIVA401 and OAdV.HIVA in nonhuman primates. These results strongly support their further exploration.

Download Full-text

Prime-Boost Immunization with Adenoviral and Modified Vaccinia Virus Ankara Vectors Enhances the Durability and Polyfunctionality of Protective Malaria CD8+T-Cell Responses

Infection and Immunity ◽

10.1128/iai.00185-11 ◽

2011 ◽

Vol 79 (5) ◽

pp. 2131-2131

Author(s):

Arturo Reyes-Sandoval ◽

Tamara Berthoud ◽

Nicola Alder ◽

Loredana Siani ◽

Sarah C. Gilbert ◽

...

Keyword(s):

T Cell ◽

Vaccinia Virus ◽

T Cell Responses ◽

Cd8 T Cell ◽

Cell Responses ◽

Modified Vaccinia Virus Ankara ◽

Boost Immunization

Download Full-text

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

Journal of Virology ◽

10.1128/jvi.00055-19 ◽

2019 ◽

Vol 93 (7) ◽

Cited By ~ 3

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.

Download Full-text

The differential production of cytokines by human Langerhans cells and dermal CD14+ DCs controls CTL priming

Blood ◽

10.1182/blood-2011-08-371245 ◽

2012 ◽

Vol 119 (24) ◽

pp. 5742-5749 ◽

Cited By ~ 81

Author(s):

Jacques Banchereau ◽

LuAnn Thompson-Snipes ◽

Sandra Zurawski ◽

Jean-Philippe Blanck ◽

Yanying Cao ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Langerhans Cells ◽

Expression Profiles ◽

Cd8 T Cell ◽

Inhibitory Effect ◽

Effector Memory ◽

Functional Difference ◽

T Cell Priming

Abstract We recently reported that human epidermal Langerhans cells (LCs) are more efficient than dermal CD14+ DCs at priming naive CD8+ T cells into potent CTLs. We hypothesized that distinctive dendritic cell (DC) cytokine expression profiles (ie, IL-15 produced by LCs and IL-10 expressed by dermal CD14+ DCs) might explain the observed functional difference. Blocking IL-15 during CD8+ T-cell priming reduced T-cell proliferation by ∼ 50%. These IL-15–deprived CD8+ T cells did not acquire the phenotype of effector memory cells. They secreted less IL-2 and IFN-γ and expressed only low amounts of CD107a, granzymes and perforin, and reduced levels of the antiapoptotic protein Bcl-2. Confocal microscopy analysis showed that IL-15 is localized at the immunologic synapse of LCs and naive CD8+ T cells. Conversely, blocking IL-10 during cocultures of dermal CD14+ DCs and naive CD8+ T cells enhanced the generation of effector CTLs, whereas addition of IL-10 to cultures of LCs and naive CD8+ T cells inhibited their induction. TGF-β1 that is transcribed by dermal CD14+ DCs further enhanced the inhibitory effect of IL-10. Thus, the respective production of IL-15 and IL-10 explains the contrasting effects of LCs and dermal CD14+ DCs on CD8+ T-cell priming.

Download Full-text