Fig. 2.

Apoptosis of CD4⁺ T cells after antigenic and mitogenic stimulation. Three replicate cultures of peripheral blood mononuclear cells were incubated with medium, PPD, Mycobacterium tuberculosis (MTB) and pokeweed mitogen (PWM) from 24 HIV⁻ PPD⁺ controls (□), 30 HIV⁻ PTB⁺ patients (hatched), 14 HIV⁺ PTB⁻ subjects (cross-hatched) and 16 HIV⁺ PTB⁺ (▪) patients. Apoptosis was assessed using the TUNEL test in combination with anti-CD4–PE. Results are expressed as percentage of TUNEL (+) CD4 T cells. Indicated in the figure are the statistical significant differences (paired t-test), between the non-stimulated and the stimulated cultures within each subject group.