Figure 4. Suppressive effect of ZL0580 on HIV in PBMCs of ART-suppressed, aviremic HIV-infected participants.

(A) PBMCs of aviremic RV254 participants (n = 5) were stimulated with anti-CD3/CD28 and cultured in IL-2–containing medium to induce latent HIV activation and CD4⁺ T cell expansion. Cells were treated with ART alone, ART+ZL0580 (2.5 μM), or were mock treated (NC). HIV release in supernatants was quantified by the 2-step nested qPCR. Following full HIV suppression, treatments were stopped and viral RNA copies were continuously monitored every 3 days. Data are shown as HIV copies (log₁₀) per 10⁶ PBMCs. (B and C) Quantitative analysis of the effect of ZL0580 on promoting HIV suppression during ART (B) and on viral rebound following ART cessation (C). Comparison of length of time (days) and AUC prior to treatment cessation (B) and after treatment cessation up until first viral rebound (C) between ART and ART+ZL0580 for the 5 PBMCs. AUC for each PBMC was quantified using Prism. (D) HIV production by unactivated RV254 PBMCs (n = 6). PBMCs were directly treated with ZL0580 (2.0 μM) or not treated (NC) on days 0, 3, and 6 (treatment stopped on day 9). HIV production in supernatants was measured once every 3 days as indicated. (E) After day 18, PBMCs were stimulated with PHA to reactivate latent HIV. HIV transcriptional reactivation was measured by quantifying Gag RNA in cells. The data are shown as fold change of ZL0580 treatment relative to NC for each PBMC. (A, D, and E) PCR was conducted in duplicate, and error bars show PCR replicate SD. *P < 0.05; **P < 0.005, (B, C, and E), paired Student’s t test.