Mice immunized with 16L2 PP7 VLPs or 18L2 PP7 VLPs are protected from vaginal challenge with HPV18 and HPV16 PsV.

<p>Groups of 5 BALB/c mice were immunized i.m. twice with 5 µg of PP7 VLPs, 16L2 PP7 VLPs or 18L2 PP7 VLPs with IFA. Three weeks after the second immunization, mice were vaginally challenged with 1.3×10⁵ (PsV18) or 3.0×10⁶ (PsV16) IU of PsV. Forty-eight hours later, luciferin was instilled vaginally and images were taken 3 minutes post-luciferin instillation. Images showing the magnitude of vaginal infection with PsV18 or PsV16 are shown in panels A and B, respectively. The colors reflect the intensity of luciferase expression. Colors are scaled for each image and shown to the right of the image. Quantitative data (shown in each panel) was extracted by drawing equally sized regions of interests surrounding the site of PsV instillation and determining average radiance (p/s/cm²/sr) by using Living Image 3.2 software. Background radiance (determined by gating on another region of the mouse) was subtracted from this value. Black-filled circles denote mice immunized with control wild-type PP7 VLPs and white-filled circles denote mice immunized with either 16L2 PP7 VLPs or 18L2 PP7 VLPs. Lines reflect the geometric mean radiance for each group.