FIG 3.

HIV-associated saliva exosomes enhance KSHV infection in oral epithelial cells. (A) OKF6/TERT2 cells were treated with HIV⁺ (pt 8 and pt 9) and HIV⁻ (N1 and N2) saliva exosomes (100 μg/ml of exosome protein) for 10 min and then infected with KSHV for 20 h. Infection was quantified by GFP flow cytometry. *, P < 0.05. (B) Human oral epithelial cells (HOECs) were infected with KSHV virion solution without dilution to test the infectivity of KSHV in primary HOECs. LANA (red) and GFP (green) expression was detected using immunofluorescent staining. Nuclei stained blue (DAPI). Bars, 50 μm. Representative images are shown. (C) HOECs were treated with saliva exosomes (100 μg exosomal protein/ml) from healthy (N1 and N2) and HIV⁺ (pt 8 and pt 9) donors, followed by KSHV infection. KSHV-infected GFP⁺ HOECs were quantified using flow cytometry. Data represent the mean ± SD. *, P < 0.05. (D) HOECs were treated with saliva exosomes (100 μg/ml of exosome protein) purified from healthy (n = 4) and HIV-infected (n = 8) donors, followed by KSHV infection. KSHV-infected GFP⁺ HOECs were determined by flow cytometry. (Right) Mean fluorescence intensity (MFI) plot of the data in the left panel. P values were determined by one-way ANOVA. (E) (Left) OKF6/TERT2 cells were infected with KSHV in the presence of Jurkat cell exosomes (Jurkat exo) or HIV⁺ J1.1 cell exosomes (J1.1 exo) for 1 and 2 h, followed by immunofluorescent staining of ORF65 (red). Representative images are shown. (Right) MFI of ORF65 staining in OKF6/TERT2 cells. Data represent those from one independent experiment (n = 4). *, P < 0.05, F test. post-inf, postinfection.