Expression of Human Papillomavirus Type 6 and Type 16 Capsid Proteins in Bacteria and Their Antigenic Characterization

Abstract

The L1 and L2 capsid proteins encoded by human papillomavirus types 6 and 16 (HPV-6 and HPV-16) have been synthesized in bacteria. Antisera were raised against the HPV-6 L1- and L2-.beta.-galactosidase fusion proteins and against an HPV-16 L1 C-terminal peptide which was 14 amino acids long. The HPV-16 L1 peptide antibodies have been shown to be highly reactive with the HPV-16 L1-.beta.-galactosidase fusion protein but not against the equivalent HPV-6 L1-.beta.-galactosidase fusion protein. The effectiveness of these antibodies was compared with commercially available anti-bovine papillomavirus type 1 (BPV-1) antibodies and the results demonstrated that the anti-BPV-1 antibodies reacted well against HPV-6 L1-.beta.-galactosidase but not against HPV-16 L1-.beta.-galactosidase. In addition, the L2 portion of the HPV-6 L2-.beta.-galactosidase fusion protein appeared particularly immunogenic, since antibodies raised against this fusion protein were predominantly reactive with the L2 moiety. The HPV-16 L1 peptide antibodies described here will be preferred reagents for the specific detection of HPV-16 capsid antigens, which may be particularly important in early diagnosis of HPV-16 infection.