Monocytes induce CD3⁺ T-cell apoptosis following Streptococcus pneumoniae challenge.

<p>Peripheral blood mononuclear cells (PBMC), plastic purified lymphocytes (Plastic purified) and highly purified CD3⁺ T-cells (CD3 enriched) were challenged for 6 h with either mock-infection (multiplicity of infection (MOI) = 0) or D39 <i>Streptococcus pneumoniae</i> (MOI = 50). A) Total Annexin V⁺ B) early apoptotic, Annexin V⁺/TO-PRO-3⁻ and C) late apoptotic/necrotic Annexin V⁺/TO-PRO-3⁺ events were recorded, n = 11. D) Hypodiploid DNA (Sub G0/1) was measured in CD3⁺ T-cells under the same conditions, n = 5. E) PBMC and CD3 enriched T-cells were challenged with D39 (D39+) MOI = 10 or mock-infected (D39−) for 16 h. CD3⁺ T-cells were purified from the PBMC and cytosolic and membrane fractions were obtained from the CD3⁺ T-cells from each sample prior to western blot analysis probing for cytochrome c, actin and Cox-4 and F) densitometry summarises the cytochrome c/actin ratio for cytosols under each experimental condition, from four experiments with separate donors.