CBP/p300 lysine acetyltransferases inhibit HIV-1 expression in latently infected T cells

Figure 4

CBP/p300 inhibition induces HIV-1 expression in CD4⁺ cells ex vivo (A) Experimental design for RGH infection of primary CD4⁺ T cells. CD4⁺ T cells isolated from an uninfected participant were infected with the RGH dual reporter virus at a low MOI. 3 days, post-infection, cells were incubated with a vehicle control (DMSO), 10 μM A-485, or 10 μM iP300w for 24 h after which proviral expression was assessed by flow cytometry. (B) Representative flow cytometry scatterplots of primary CD4⁺ T cells treated as in (A). Latent infections are in Q1 (mCherry+), productively infected T cells are in Q2 (GFP+/mCherry+), noise generated by viral recombination is in Q3 (GFP+), and uninfected cells are in Q4. (C and D) Following treatment of primary CD4⁺ T cells as in (A), proviral transcription was determined by flow cytometry and is expressed as the percentage of productive infections (C) and the GFP mean fluorescence intensity (MFI) of infected cells (D) (n = 3, mean ± SD, one-way ANOVA with Dunnett’s multiple comparisons test). (E) Viability was determined for participant derived CD4⁺ T cells treated as in (A) (n = 3, mean ± SD, one-way ANOVA with Dunnett’s multiple comparisons test). (F and G) Primary CD4⁺ PBMCs isolated from people living with HIV-1 who are receiving ART were treated with a vehicle (DMSO), 10 μM A-485, or 10 μM iP300w and were either left unstimulated or were treated with anti-CD3/anti-CD28. Following 24 h, intracellular RNA was extracted, and RT-PCR was preformed using oligos specific for multiply spliced Tat-Rev HIV-1 mRNA transcripts. HIV-1 mRNA expression is normalized to GAPDH (n = 3, mean ± SD, unpaired t test). (H) Primary CD4⁺ PBMCs treated as in (F) and (G) were assessed for cellular viability (n = 2, mean, unpaired t test). Statistical significance is indicated at ∗p < 0.05, ∗∗p < 0.01, or ∗∗∗p < 0.001, with n.s. denoting non-significant p ≥ 0.05.