Fig. 4

Antibodies to integrin α9β1 inhibit KSHV escape from the late endosome. A KSHV is present in Rab5-positive EEs and Rab7-postive LEs. HFF cells were either uninfected or pre-treated (1 h at 37 °C) with antibodies (20 µg/ml) to α9β1 or pre-immune IgG prior to infection with FITC-KSHV for 1 min (A) and 30 min (B) at 37 °C. Cells were washed, fixed, and subsequently immunostained with TRITC labeled anti-Rab5 antibodies (A) and TRITC labeled anti-Rab7 antibodies (B ) prior to mounting using an anti-fade reagent containing DAPI and examining under a fluorescent microscope. Representative images are provided at ×1000 magnification. The white circles indicate co-localization of FITC-KSHV with the respective endosome marker within the cell (panels A and B)