Tat-induced MCP-1 secretion from HMVEC-Ls.

Serum-starved cells were stimulated with different doses of HIV-1 Tat protein (A) or with 50 ng/mL of Tat plus 10 U/mL of heparin or 10 U/mL heparin alone (0) for the indicated times (B). After stimulation, the levels of MCP-1 in the culture supernatants were titrated, as described in “Materials and methods.”