Fig 5.

CD14⁺ HIV-1 can trigger TLR4 signaling and NF-κB activation by delivering LPS to human monocytes. (A) Schematic describing how virions were “loaded” with LPS before overlaying onto TLR4-expressing cells. (B) NF-κB was proxied by measuring SEAP activity from TLR4-expressing (Tlr4^+/+) THP1-Dual cells induced after 24-h stimulation with samples. Bars are mean ± SD across four to five independent experiments, and where indicated, at least four different virus stocks were tested each time. Statistical significance was evaluated with one-way analysis of variance (ANOVA) (α = 0.05) and Tukey’s correction for multiple comparisons. From left to right: n = 21, n = 11, n = 12, n = 21, n = 16, n = 22, and n = 22. ns, non-significant; ****P < 0.0001. (C) Experiment as in (B) but done on TLR4-KO (Tlr4^-/-) THP1-Dual cells. Data are mean ± SD of two independent experiments using four different virus stocks. Statistical significance was evaluated as in (B). From left to right: n = 7, n = 6, n = 7, n = 4, n = 4, n = 6, and n = 8. ns, non-significant; **P = 0.0014; ****P < 0.0001. (D) Secreted TNF-α was measured by ELISA from stimulated (24 h) THP-1 cells. Data are mean ± SD across two independent experiments with four different virus stocks. Statistical significance was evaluated with one-way ANOVA (α = 0.05) and Tukey’s correction for multiple comparisons. From left to right: n = 8, n = 8, n = 8, n = 4, n = 4, n = 8, and n = 8. ns, non-significant; **P = 0.0052; ****P < 0.0001.