Human MDMs specifically activate STAT1 on treatment with rNef.

(A) Western blot analysis of phosphotyrosine-STAT1, STAT1, and β-tubulin levels detected on total cell extracts assayed at different times after addition of 100 ng/mL rNef. (B) Phosphotyrosine-STAT1, STAT1, and β-tubulin amounts detected through Western blots performed on total cell extracts of MDMs treated for 2 hours with medium complemented with 100 ng/mL rNef or with the same medium after treatment with anti-Nef–specific antibodies or unspecific, species-matched antibodies, and clearing with protein A-G agarose. (C) Western blot analysis of phosphotyrosine-STAT1, STAT1, and β-tubulin levels detected on total cell extracts of human MDMs after treatment for 2 hours with different doses (ie, 0.1-100 ng/mL) of rNef or with 100 ng/mL rUvp-1. In all panels, analysis on control cell cultures was carried out on cells harvested concurrently with the later time points considered for treated cells. Specific signals are indicated on the left side; molecular size markers (in kilodaltons) are reported on the right.