Fig 7. HIV-1 Tat induces SOCS1 expression.

(A) Human monocytes, dendritic cells or HEK-TLR4-CD14-MD2 cells (10⁶) were stimulated or not for 24 h with Tat (100 nM) and tested for SOCS1 expression. LPS (10 ng/mL) or LPS + IFN-γ (10 ng/mL) were used as positive control. Actin was used as a loading control. (B) HEK-Null used as control or HEK cell line expressing TLR4-CD14-MD2 were stimulated with GST-Tat 1–45 (100 nM), GST-Tat 30–72 (100 nM) or LPS (10 ng/mL) +/- IFN-γ (10 ng/ml). The specificity of the Tat effect was tested in the presence of anti-Tat antibodies at 1 μg/ml. Stimulation with GST or with anti-Tat alone was used as controls. Quantification of the band obtained from 3 independent experiments was performed using Image J Software. Asterisks represent P values: *, P ˂ 0.05; **, P ˂ 0.01; ***, P ˂ 0.001, ns non significant.