Figure 1. Increased activation of caspase-1 and caspase-3 in CD4⁺ T cells during chronic HIV-1 infection.

(A) Representative flow cytometry plot shows FLICA–caspase-1 and active caspase-3 expression in CD4⁺ T cells in peripheral blood of healthy controls (HC), viremic patients (VIR), antiretroviral therapy–treated patients (ART), and elite controllers (EC). (B and C) The frequencies of FLICA–caspase-1⁺ CD4⁺ T cells (B) and active caspase-3⁺ CD4⁺ T cells (C) from HCs (n = 19), VIR patients (n = 80), ART patients (n = 27), and ECs (n = 7). (D and E) Association of the frequencies of FLICA–caspase-1⁺ CD4⁺ T cells (D) and active caspase-3⁺ CD4⁺ T cells (E) with the absolute CD4⁺ T cell counts in VIR patients. Each dot represents a single individual, and associations were evaluated using Spearman’s correlation test. P and Spearman’s ρ values are presented. (F) CD4⁺ T lymphocytes from 6 VIR patients were downsampled, concatenated, and mapped by t-SNE. Each point represents a single cell. Different light colors represent different subsets. The FLICA–caspase-1⁺ CD4⁺ T cells (blue) and active caspase-3⁺ CD4⁺ T cells (red) were overlaid onto the overall t-SNE map. (G) The proportion of naive T (Tn), Tcm, Ttm, Tem, and Ttd cells in the total, FLICA–caspase-1⁺, and active caspase-3⁺ CD4⁺ T cell population from VIR patients (n = 6). Different symbols represent different individuals. (H) The Tcm/Tem ratio was calculated. Mann-Whitney U test (B and C); Wilcoxon’s signed-rank test (G and H); *P < 0.05, **P < 0.01, ***P < 0.001. pos, positive.