The kinetics and stimulant dependence of cytokine production by blood and bronchoalveolar lavage T cells evaluated at the single cell level

We have previously shown that bronchoalveolar lavage (BAL) T cells from hum an airways predominantly produce interferon gamma (IFN-gamma) and interleuk in 2 (IL-2) when stimulated es vivo. The kinetics of TH1 and TH2 cell cytok ine production by T cells from both blood and BAL were studied to establish the optimal time after stimulation either with pharbol myristate (PMA) and ionomycin or with the more physiological stimulus of anti-CD3 for intracel lular cytokine detection of IFN-gamma, IL-2, IL-3 and IL-5 in both blood an d BAL T cells. The optimal time for positive identification of IL-2 in both blood and BAL was 5 h after PMA/ionomycin stimulation, whereas the first p eak for IFN-gamma was found after 5 h in blood but after only 3 h in BAL. T cells from different biological compartments responded differently to each of the stimuli. Whilst anti-CD3 stimulation did not induce TH1 cytokine pr oduction in blood T cells, it readily induced both IFN-gamma and IL-2 produ ction in BAL T cells. The kinetics of cytokine production were found to be stimulus dependent. Whilst IL-2 production showed similar kinetics with bot h stimuli, the kinetics of IFN-gamma production differed between stimuli. We have also examined the effect of five different stimuli on cytokine prod uction by T cells to determine whether different forms of stimulation may s electively stimulate or inhibit different cytokines, Not surprisingly, PMA/ ionomycin induced a greater percentage of BAL T cells to produce TH1 cytoki nes. However, other than modest amounts of the TH[2 cytokines IL-4 and IL-5 were not induced by any of the five stimuli. (C) 1999 Academic Press.