TITRATION OF HPV-11 INFECTIVITY AND ANTIBODY NEUTRALIZATION CAN BE MEASURED IN-VITRO

Human papillomavirus type 11 (HPV-11), produced from the athymic mouse xenograft system, was shown to infect cultured neonatal human foreski n keratinocytes and the HaCaT keratinocyte cell line in vitro. Infecti on was documented by the appearance of HPV-ll-specific spliced mRNA, d etected by reverse transcriptase-polymerase chain re action, Purified HPV-11 virions at concentrations of approximately 10(7) particles/ml c ould successfully evoke infection in this system, Infection was comple tely abrogated by preincubation of the HPV-11 inoculum with mouse anti -HPV-11 monoclonal antibodies, experimentally immunized animal sera, o r sera of human patients with HPV infection. Concurrent detection of c ellular mRNA for the beta-actin gene, also by reverse transcriptase-po lymerase chain reaction, provided an internal control confirming RNA r ecovery and successful reverse transcriptase-polymerase chain reaction . Using this approach, it was possible to determine semiquantitative t iters for test solutions of HPV-11-neutralizing antibodies, The in vit ro system for HPV-11 infectivity and neutralization map be useful in t he study of the immune response to HPV-11 infection or immunization in patients.