Effect of four different alloantigen-stimulated cell lines on HIV-1 infection. PHA blasts were infected with HIV-1_BZ167 (172 TCID₅₀/10⁵ cells) and cultured in the absence (□) or the presence (•) of alloantigen-stimulated cell lines, derived from cells obtained from the same donor as the one used to generate the blasts, at a ratio of 1:1. The respective percentages of inhibition on days 3 and 6 of culture were: (A) 82% and 39%; (B) 100% and 87%; (C) 100% and 99%; and (D) 96% and 74%. The results represent means of triplicate cultures.