PLASMID DNA-BASED IMMUNIZATION FOR HEPATITIS-C VIRUS STRUCTURAL PROTEINS - IMMUNE-RESPONSES IN MICE

Background & Aims: Plasmid DNA-based immunization has been shown to be an effective means of vaccination in animal models. In this study, th e immune responses to various hepatitis C virus structural protein ant igens weve evaluated using this technique. Methods: Six recombinant pl asmids were constructed. These include, individually, the coding regio ns for the core protein (pC); E1 (pE1) and E2 (pE2); as well as cove, E1, and E2 together (pCE1E2); E1 and E2 together (pE1E2); and finally an E2 construct from which the N-terminal hypervariable region had bee n deleted (pE2 Delta HVR). These plasmids were transfected into mammal ian cells to test their protein expression and were injected into the quadriceps muscles of BALB/c mice to measure specific antibodies and c ytotoxic T-lymphocyte responses. Results: All the recombinant plasmids weve shown to express specific antigens transiently in cells and elic ited specific antibody responses to core, El, and E2 in mice. Specific cytotoxic T lymphocyte responses were detected only in mice injected with plasmid constructs encoding the core. Conclusions: Genetic immuni zation can aid the development of hepatitis C virus vaccines by allowi ng for the rapid construction and evaluation of different expression p lasmids as potential immunogens.