FIG. 6.

Induction of L1-specific antibodies by DNA immunization. Fifteen mice falling into four groups were immunized by injection of plasmid DNA. Anti-L1-specific antibodies were measured by an HPV-16 VLP-specific ELISA. ▪, five mice immunized with the expression plasmid containing the L1h gene; ○, five mice immunized with the plasmid containing the L1ori gene. The control group consisted of four mice immunized with an expression vector containing a non-L1 gene (VP22-E7) (▴) and one nonimmunized mouse (⧫).