TABLE 2.

Induction of T-cell death by supernatant and cell-cell contact of C. trachomatis-infected macrophages

Cultivation of PHA-activated T cells plus:	% of viable cellsa (Pb) after induction with:
	Supernatant	Cells
Noninfected macrophages	100	100
Macrophages infected with C. trachomatis at an MOI of:
1	87 ± 9 (0.005)	84 ± 12 (0.0001)
5	78 ± 8 (0.0001)	61 ± 9 (0.0001)

^aPercentages represent the viability of PI-stained cells under different culture conditions compared to the viability of noninfected cultures. Values are means ± standard deviations (six independent experiments, four performed in duplicate and two performed in triplicate). Supernatants were derived from macrophages after 6 days of culture prior to the addition of T cells. FACS analysis for PI-stained cells was performed after 6 days of culture. 

^bAll values were highly significantly different (P < 0.01) from value for preactivated T cells cocultivated with supernatant from uninfected macrophages or from value for preactivated T cells cocultivated with noninfected macrophages, as determined by one-way ANOVA.