Replication kinetics of SIV239, SIV316open, 316TMstop, and SIV239/Env251 virus clones in rhesus macrophage cultures. Rhesus monkey macrophages were obtained from bronchoalveolar lavage and were infected with viruses after being cultured for 48 h. The p27 content in the supernatant was measured using an antigen capture assay. (A and C) Macrophages from Mm 222-06 were infected with SIV239, SIV316open, SIV316TMstop, and SIV239/251a–j and p27 amounts graphed with (A) and without (C) SIV316open and SIV316TMstop. (B and D) Macrophages from Mm 280-06 were infected with SIV239, SIV316open, SIV316TMstop, and SIV239/251k-t and p27 amounts graphed with (B) and without (D) SIV316open and SIV316TMstop.