Mucosal and systemic immunization with BPVL1E7VLP vaccine induce effective cellular immunity

To examine the induction of immune response in the genital tract mucosa, subcutaneous and nasal routes of immunization with bovine papillomavirus type 1 (BPV1) virus-like particles (VLPs) were studied for their ability to induce systemic as well as mucosal immune responses. BPV1VLPs containing a HPV16E7 CTL epitope (BPVL1E7 VLP) were administered subcutaneously or intranasally to mice. After immunization, anti BPVL1E7 immunoglobulineG (IgG) antibodies, IgG1 and IgG2a in the serum and anti BPVL1E7 IgA antibodies in vaginal secretions were measured by ELISA assays. Specific IgG antibodies in serum were observed after immunization via subcutaneous and nasal routes. Both immunization routes gave a high ratio of IgG2a/IgG1 thus indicating a Th-1 type immune response. These data suggest that both systemic and mucosal immunization of BPVL1E7 VLP elicited a good Th1 type immune response which may be useful in protecting against local HPV infection