Figure 7

HPV-16 PsVs in senescent cells are accessible to neutralising antibody. (a) Anti-L1 (H16.V5) neutralising antibody binds to the surface of senescent and proliferating cells. Senescent BJ cells were transfected with control siRNA and p53 siRNA. 48 h after transfection cells were incubated with anti-L1 neutralising antibody for 24 h. Then cells were fixed and neutralising antibody was detected with goat anti-mouse rhodamine antibody (red) and rabbit antibody against EEA-1, and detected using Alexa Fluor 647-conjugated donkey anti-rabbit (blue). Two examples are shown for each condition. (b) In infected senescent cells the H16.V5 neutralising antibody co-localises with the virus on the surface of cells. One day after siRNA transfection, AF488-labelled HPV-16 PsVs (green) were added to the cells. 24 h after infection cells were incubated overnight with neutralising H16.V5 antibody, fixed and stained as above. Note that in senescent cells transfected with the control siRNA, H16.V5 neutralising antibody co-localises with the virus on the cell surface (indicated by arrows). In cells that were transfected with the p53 siRNA there is very little co-localisation between the virus and neutralising antibody and virus is visible within the cells, as indicated by the arrows, suggesting that virus entry is stimulated post–transfection of the p53 siRNA.