A recombinant human papillomavirus (HPV) type 16 L1–vaccinia virus murine challenge model demonstrates cell-mediated immunity against HPV virus-like particles

Abstract

Human papillomavirus (HPV) virus-like particles (VLP) are emerging as the immunogen of choice for prophylactic vaccines. The inability to infect animals with HPV has prevented the testing of potential vaccines such as these in animal systems. This study describes the development of a recombinant vaccinia virus (VV)–HPV type 16 (HPV-16) VLP challenge model to evaluate the efficacy of the cell-mediated immune response following HPV-16 VLP immunization in mice. Inoculation of BALB/c and C57 BL/6 mice with HPV-16 VLP resulted in HPV VLP-specific T cell proliferative responses characterized by the production of both Th1 and Th2 cytokines, and afforded protection against virus challenge from recombinant VV expressing HPV-16 L1 (VVL1R-16). Protection was demonstrated by a 4·6 log10 reduction in ovarian titres of VVL1R-16 in vaccinated BALB/c mice and a 2·3 log10 reduction in vaccinated C57 BL/6 mice, compared with unvaccinated mice.