HIV-1 Tat-protein-induced TNF-α and IL-10 is TLR4-dependent. A-B) Monocytes were pretreated or not with increasing amounts of blocking antibodies against TLR4 or TLR2 or isotype control for 1h before stimulation by GST-Tat 1–101. C) Mab anti-TLR4 (1 μg/ml) were incubated for 1 h with 106 human monocytes before stimulation with 1, 10 or 100 nM of Tat or with, D) 100 nM of GST-Tat 1–101, GST-Tat 1–45, or GST-Tat 30–72. GST was used as a control. After 24 h, TNF-α and IL-10 in the supernatant (SN) were measured by ELISA. After 24 h, TNF-α and IL-10 were measured in the SN. The values are representative of three independent experiments. E) Monocytes were treated with LPS (1 ng/ml) or GST-Tat1-101 (10 nM) in the presence or not of LPS-RS (1 μg/ml). After 24 h, TNF-α and IL-10 were quantified in the culture supernatant by ELISA. Data represent means +/− SD.