Aim: To investigate the effect of different stimuli and different culture conditions on the cytokine expression of CD4+ and CD8+ T cells.
Methods: PBMCs were isolated from normal human peripheral blood and cultured with three kinds of stimuli (PHA, anti-CD3 and anti-CD28 mAbs, PMA and ionomycin) under four different culture conditions (room temperature, 37 degrees C water bath, 37 degrees C incubator, 37 degrees C and 50 mL/L CO2 incubator) for 4.5 ~ 5 h and intracellular cytokines (IL-2, IFN-gamma and TNF-alpha) in T cells were assessed by flow cytometry (FCM).
Results: Cytokine expression of CD4+ and CD8+ T cells varied when treated with different stimuli under different conditions. PMA had the strongest stimulative effect on cytokine expression of PBMC, while the effect of anti-CD3 mAb was weaker, and that of PHA was the weakest. Different culture conditions did not greatly change the cytokine expression profile of T cells (P>0.05) except that there were very few cytokine producing cells when PBMCs were cultured at room temperature.
Conclusion: Anti-CD3 and anti-CD28 mAbs, PMA and ionomycin are recommended for the stimulation of PBMCs and detection of intracellular cytokine using FCM. Culture temperature but not the concentration of CO2 is the most important factor during the short term T cell stimulation.