CELLULAR IMMUNE RESPONSES TO HPV-18, -31, AND -53 IN HEALTHY VOLUNTEERS IMMUNIZED WITH RECOMBINANT HPV-16 L1 VIRUS-LIKE PARTICLES
Virology. 2006 Sept 30:353(2):451-62
Pinto LA, Viscidi R, Harro CD, Kemp TJ, Garcia-Pineres AJ, Trivett M, Demuth F, Lowy DR, Schiller JT, Berzofsky JA, Hildeshelm A.
HPV Immunology Laboratory, SAIC-Frederick, Inc./NCI-Frederick, Frederick Building 469, Room 120, Frederick, MD 21702, USA
Human papillomavirus-like particles (HPV VLP) are candidate vaccines that have shown to be efficacious in reducing infection and inducing robust antiviral immunity. Neutralizing antibodies generated by vaccination are largely type-specific, but little is known about the type-specificity of cellular immune responses to VLP vaccination. To determine whether vaccination with HPV-16 L1VLP induces cellular immunity to heterologous HPV types (HPV-18, HPV-31, and HPV-53), we examined proliferative and cytokine responses in vaccine (N=11) and placebo (n=5) recipients. Increased proliferative and cytokine responses to heterologous types were observed postvaccination in some individuals. The proportion of women responding to heterologous types postvaccination (36%-55%) was lower than that observed in response to HPV-16 (73%). Response to HPV-16 VLP predicted response to other types. The strongest correlations in response were observed between HPV-16 and HPV-31, consistent with their phylogenic relatedness. In summary, PBMC from HPV-16 VLP vaccine recipients can respond to L1VLP from heterologous HPV types, suggesting the present of conserved T cell epitopes.