Figure 4. Activation of caspase-1 is mediated by the NLRP3 inflammasome during chronic HIV-1 infection.

Peripheral blood CD4⁺ T cells of HCs (n = 6), VIR patients (n = 22), ART patients (n = 11), and ECs (n = 3) were enriched by magnetic cell sorting. (A) Heatmap showing inflammasome-related gene expression. (B) Heatmap of pairwise correlation of inflammasome-related gene expression with FLICA–caspase-1⁺ CD4⁺ T cell frequency, viral load, and CD4⁺ T cell counts. (C) Correlations of FLICA–caspase-1⁺ CD4⁺ T cell frequency with inflammasome-related gene expression. (D) PBMCs from VIR patients (n = 5) were cultured with vehicle control or MCC-950 (1 μM) for 6 hours. FLICA–caspase-1⁺ CD4⁺ T cell frequencies, IL-1β secretion, and lactate dehydrogenase (LDH) release were determined. (E) Left: Representative NLRP3 expression in CD4⁺ T cells of HCs (red) and VIR patients (blue). Right: MFI of NLRP3 expression in CD4⁺ T cells from HCs (n = 5) and VIR patients (n = 5). FMO, fluorescence minus one. (F) PBMCs from HCs (n = 4) and VIR patients (n = 4) were stimulated with 10 μM nigericin, 5 mM ATP, or HIV-1 viral particles (Bal-GFP, R5-tropic), respectively. FLICA–caspase-1⁺ CD4⁺ T cell frequencies were determined by flow cytometry, and supernatant IL-1β levels were detected by ELISA. (G) PBMCs from HCs (n = 4) were treated with conditioned medium (CM) for 48 hours; then HIV-1 viral particles (Bal-GFP, R5-tropic) were added and incubated for an additional 24 hours. (H) MFI of NLRP3 in CD4⁺ T cells (left) and FLICA–caspase-1⁺ CD4⁺ T cell frequencies (right). (I) Left: Representative MitoSOX (Thermo Fisher Scientific) signal of VIR patients (n = 10). Right: MFI of MitoSOX signals. (J) PBMCs from VIR patients (n = 5) were cultured in the presence of 1 mM N-acetylcysteine (NAC) or 20 μM MitoTEMPO. Frequency of FLICA–caspase-1⁺ CD4⁺ T cells determined by flow cytometry. Mann-Whitney U test (E); Wilcoxon’s signed-rank test (D, F, H, I, and J); *P < 0.05, **P < 0.01, ***P < 0.001.