Figure 1. TGF-β inhibits HIV-1 latency reactivation in vitro.

(A–E) U1 and ACH-2 cells were treated with TGF-β1 (10 ng/mL) or galunisertib (GAL) (1 μM) or both or were mock treated in presence versus absence of PMA (100 ng/mL) for 18 hours and stained for intracellular p24. (A) An example of p24 detection in 1 experiment with U1 cells. (B and C) Raw p24 data from 1 representative experiment with U1 (B) or ACH-2 (C) cells (black circles: mock; blue squares: TGF-β1; green triangles: TGF-β1 + gal; pink triangles: galunisertib only). (D and E) Summary fold increase in the frequency of p24⁺ cells over the mock condition (box plot with median line and min/max whiskers) shown from 5 similar experiments (U1 on the left; ACH-2 on the right). (F and G) For this primary CD4⁺ T cell model of latency, CD4⁺ T cells were isolated from PBMCs, activated, infected by spinoculation, and incubated for 2 days in the presence of T20. PMA (100 ng/mL) was used for reactivation of latently infected cells for 18 hours in the presence of TGF-β1 (10 ng/mL) or galunisertib (1 μM), both, or mock treatment. A schematic of the experiment is shown in F. (G) Summary data (fold increase over the unstimulated condition) from 5 experiments with cells from different donors run in triplicate. (H) Data from a model of DC-driven HIV reactivation from U1 cells are shown. Fold difference in the frequency of p24⁺ U1 cells in absence versus presence of moDCs or TGF-β DCs shown for 5 different experiments in triplicate (box plot with median and min/max whiskers). (A–H) Conditions were compared by Kruskal-Wallis ANOVA test followed by the Dunn’s test corrected for multiple comparisons. Significant P values of α < 0.05 (*), α < 0.01 (**), and α < 0.001 (***) are indicated. All other comparisons were nonsignificant. Box-and-whisker plots represent median, 25th and 75th percentile, with whiskers going from min to max.