FIG. 3.

Apoptosis of nonpreactivated T cells induced by macrophages (MO) infected with C. trachomatis at an MOI of 5. After 6 days of coculture, the number of apoptotic cells was quantified by microscopic analysis of TUNEL assays (n = 3 experiments). Mean percentages of apoptotic cells ± standard deviations were as follows: for cultures of nonpreactivated T cells, 15% ± 3% (noninfected) and 35% ± 5% (C. trachomatis infected); for cultures of PHA-preactivated T cells, 28% ± 7% (non-infected) and 56% ± 11% (C. trachomatis infected). P values of the indicated comparisons were determined by one-way ANOVA accounting for multiple comparisons by using the Tamhane test. This analysis revealed that for both T-cell populations a highly significant increase in numbers of apoptotic cells occurred in the presence of C. trachomatis-infected macrophages (P = 0.001). Abbreviations: MO, macrophage; TC, T cell; Ctr., C. trachomatis.