Figure 3

Proinflammatory cytokine secretion mediated by TLR7/8 in monocytes varied based on HIV-infection status and correlated positively with CD4 ⁺ cell counts of peripheral blood in HIV-infected subjects. Ex vivo monocytes from uninfected (n = 10) and HIV-infected (n = 10) subjects were cultured in the presence of TLR 7/8 ligand R-848 or media alone for 24 h. Culture supernatants were assessed for cytokine levels using an ELISA assay. (A) R-848 stimulation produced significantly greater TNF-α production in monocytes of both HIV-infected and uninfected subjects compared with unstimulated samples (p < 0.0001); stimulated uninfected subjects produced more TNF-α than stimulated HIV-infected subjects (p = 0.0412). R-848 also induced significantly greater IL-12p40 production in monocytes of both HIV-infected (p < 0.0001) and uninfected subjects compared with unstimulated monocytes (p < 0.0001). No statistically significant increase in IL-12p40 was observed in HIV-infected versus uninfected subjects (P = 0.198). TNF-α levels were analyzed using the Mann-Whitney U two-tailed test. Independent t test were used to analyze IL-12p40 levels. The significant differences are represented as p value (* p < 0.0001 compared with unstimulated by R-848, # p = 0.0412 compared with uninfected subjects). All data are expressed as the mean ± SEM values from experiments performed in triplicate. (B) Levels of TNF-α and IL-12p40 secreted by monocytes via TLR7/8 were significantly correlated with CD4⁺ cell counts in the ten HIV-infected individuals. (C) TNF-α exhibited a significant positive correlation with IL-12p40 in HIV-infected individuals. Data was analyzed using a Pearson correlation. Experiments were repeated at least 2 times with similar results. (D) The level of TNF-α and IL-12p40 secretions of triggered monocytes derived from 31 subjects belonging to the four categories (7 subjects of SPs, 10 of HIV Chronic, 7 of AIDS and 7 of Negative) were described (*p < 0.05).