Effect of Th1 and Th2 cytokines on morphologic features of apoptosis in monocyte culture. Ultraviolet fluorescence microscopic analysis of monocytes (1 × 105 cells/mL) cultured for 48 hours in poly–L-lysine coated plates in the presence of medium alone (A) or either IL-2 (200 IU/mL; B), IFN-γ (10,000 IU/mL; C), IL-12 (400 ng/mL; D), IL-4 (400 ng/mL; E), IL-10 (400 ng/mL; F ), or a mixture of IL-4 (400 ng/mL) and IL-10 (400 ng/mL; G). After the 2-day culture, cells were treated with two fluorescent nuclear dyes, YOPRO-1 (10 μmol/L, for 5 minutes), which stains apoptotic cells in green, and Hoechst 33342, which stains in blue nuclei from both living and apoptotic cells (original magnification × 250); percentages of apoptotic cells were 18% (A), 17% (B), 32% (C), 16% (D), 30% (E), 38% (F ), and 55% (G). Two hundred cells were counted in each field, and results are mean from analyses of three fields for each experimental condition. These results are from one representative experiment out of three.
