FIG 6.

HIV⁺ exosomes enhance KSHV infection in an EGFR-dependent fashion. (A) KSHV infection in OKF6/TERT2 cells treated with exosomes from Jurkat or J1.1 cells (4 × 10⁹ exosomes/ml) with or without cetuximab (20 μg/ml). GFP⁺ cells were detected by flow cytometry. Data (mean ± SD) represent those from one independent experiment out of three repeats. no KSHV, no KSHV infection control; Ctrl, no exosome treatment control. *, P < 0.05. (B) OKF6/TERT2 cells were pretreated with J1.1 and Jurkat cell exosomes (4 × 10⁹ ml) in the presence or absence of cetuximab (Cet) or AG1478 (2 μm) for 30 min, followed by KSHV infection for 20 h for total protein extraction and immunoblotting of LANA and ORF K8. Tubulin was used as a loading control. (C) Flow cytometry of GFP⁺ HOECs treated with exosomes isolated from the culture supernatants of Jurkat cells or J1.1 cells or with EGF (10 ng/ml) in the presence or absence of cetuximab (20 μg/ml) (n = 3). *, P < 0.05. (D) OKF6/TERT2 cells were treated with EGF (10 ng/ml) for 10 min or remained untreated, followed by KSHV infection for 2 h. ORF65 (red) was detected by immunofluorescent staining. Representative images are shown. (E) Oral buccal mucosal tissue cultures (MatTek Inc.) were treated with J1.1 or Jurkat cell exosomes (4 × 10⁹/ml) in the presence or absence of cetuximab (20 μg/ml), followed by KSHV infection for 20 h. Cells were stained for LANA and GFP. Arrowheads, LANA; green, GFP; blue, nuclei. The lower left image represents the zoomed-in box of each merge photo to detail cellular expression of GFP and LANA.