SEROLOGICAL DIFFERENTIATION OF HUMAN PAPILLOMAVIRUS TYPE-11, TYPE-16 AND TYPE-18 USING RECOMBINANT VIRUS-LIKE PARTICLES

The L1 major capsid protein-coding sequences of human papillomavirus ( HPV) types 11, 16 and 18 were expressed in the baculovirus system. Vir us-like particles (VLPs) were purified from recombinant-infected Spodo ptera frugiperda Sf9 cells and cell-free culture supernatants. Rabbits immunized with purified VLPs developed antibodies that reacted only w ith the specific VLP type used as the immunogen. In addition, rabbit a ntibodies raised against infectious HPV-11 virions only reacted with H PV-11 L1 VLPs and not with VLPs derived from either HPV-16 or HPV-18. These results suggest that HPV-11, HPV-16 and HPV-18 virions are antig enically distinct from one another. This observation should be conside red in future studies of immune responses to HPV.