DNA immunization with hepatitis C virus (HCV) polycistronic genes or immunization by HCV DNA priming-recombinant canarypox virus boosting induces immune responses and protection from recombinant HCV-vaccinia virus infection in HLA-A2.1-transgenic mice.
We studied immune responses to hepatitis C virus (HCV) genes delivered as DNA encoding the entire HCV protein coding genome in two polycistronic plasmids encoding HCV capsid-E1-E2-NS2-NS3 and HCV NS3-NS4-NS5 in HLA-A2.1-transgenic mice. Immune responses to HCV DNA prime and recombinant canarypox virus boost were also studied with the above constructs. At 8 weeks after a canarypox virus boost, the DNA prime/canarypox virus boosting regimen induced potent cellular immune responses to HCV structural and nonstructural proteins on target cells expressing the HLA-A2.1 allele. High frequencies of gamma interferon-secreting cells, as detected by enzyme-linked immunospot assay, were obtained in response to several endogenously expressed HCV proteins. We also observed cytotoxic-T-lymphocyte reactivity in response to endogenously expressed HCV proteins in fresh spleen cells without in vitro expansion. Upon challenge with a recombinant vaccinia virus expressing HCV proteins at 2 months postimmunization, the HCV DNA prime/canarypox virus-immunized mice showed a complete reduction in vaccinia virus titers compared to HCV DNA prime/boost- and mock-immunized controls. Immune responses were still detectable 4 months after canarypox virus boost in immunized mice. Interestingly, at 10 months postimmunization (8 months after canarypox virus boost), the protection in HCV DNA prime/boost-immunized mice against recombinant HCV-vaccinia virus challenge was higher than that observed in HCV DNA prime/canarypox virus boost-immunized mice.
Pancholi
Preeti
P
Laboratory of Virology, Lindsley F. Kimball Research Institute of the New York Blood Center, New York 10021, USA.
Perkus
Marion
M
Tricoche
Nancy
N
Liu
Qingyan
Q
Prince
Alfred M
AM
D000818:Animals; D016827:CD8 Antigens / Q000502:physiology; D028121:Canarypox virus / Q000235:genetics; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D005796:Genes; D015789:HLA-A2 Antigen / Q000502:physiology*; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology*; D006526:Hepatitis C / Q000517:prevention & control*; D007114:Immunization; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014407:Tumor Cells, Cultured; D019444:Vaccines, DNA / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology*; D014761:Viral Hepatitis Vaccines / Q000276:immunology*
D016827:CD8 Antigens; D016207:Cytokines; D015789:HLA-A2 Antigen; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic; D014761:Viral Hepatitis Vaccines; D007371:Interferon-gamma