Fig. 6

In coculture with monocytes, Treg cells suppress TNF-α production following stimulation with poly-ICLC. In a, representative plots of TNF-α forming monocytes are shown for both ART naive HIV-1 infected and uninfected participants. The addition of poly-ICLC in the culture medium enhanced the production of TNF-α by monocytes compared to monocytes cultured alone, without significant difference (P > 0.05; b, c, d, e). Upon co-culture with autologous Treg cells, a significant reduction of TNF-α production was observed. This suppressive activity of Treg cells correlated positively with helper CD4⁺ T cell counts (r = 0.67, P < 0.0001; f, g) and negatively with HIV-1 plasmatic viral loads (r = − 0.5, p = 0.0042; h, i). In contrast to IL-6, no correlation was observed between the stimulation and the suppression index (P > 0.05; j). Horizontal bars represent the Median values that were compared using the Kruskal Wallis test followed by Dunn’s multiple comparisons post-test. Correlation coefficients and their significance were calculated using the Spearman test. The letters on horizontal bars identify which groups are significantly different from each other. The same letter implies there is no significant difference between the compared groups, while different letters indicate a significant difference between them