AN ANALYSIS OF INTERFERON-GAMMA, IL-4, IL-5 AND IL-10 PRODUCTION BY ELISPOT AND QUANTITATIVE REVERSE-TRANSCRIPTASE PCR IN HUMAN PEYERS-PATCHES

The cytokine profiles of mononuclear cells freshly isolated from Peyer 's patch (PPMC), adjacent ileal lamina propria lymphocytes (LPMC) and peripheral blood (PBMC) in children without histological evidence of g astrointestinal disease has been investigated by single-cell enzyme-li nked immunoabsorbent spot forming assay (ELISPOT) and reverse transcri ptase (RT)-PCR. In the blood, interferon gamma and IL-4 ELISPOTs were regularly detected albeit at low frequency (<50/10(5) cells). IL-5 and IL-10 ELISPOTs were not seen in most patients. In Peyer's patches and lamina propria there was a dramatic increase in cytokine secreting ce lls of all types compared to blood, reaching a very high frequency for interferon gamma in the lamina propria (1000-3000/10(5) cells). IL-4 and IL-5 ELISPOTs were 20-100-fold less common in both PP and LPL. At all sites, cytokine secretion depended on protein sythesis and enrichm ent for CD4(+) cells in PP increased the frequency of all cytokine-sec reting cells. Quantification of messenger RNA for cytokines using RT-P CR demonstrated that IL-4 and IL-10 transcripts were significantly gre ater than interferon gamma transcripts in PP and in lamina propria, IL -4, IL-10 and interferon gamma transcripts were equivalent. IL-5 trans cripts were not detected in most samples of PP and lamina propria. The se results clearly show that cells secreting interferon gamma predomin ate in human PP and LPL. However the high mRNA concentrations for IL-4 and IL-10 shows that although these cells are quantitatively few, the y are highly transcriptionally active. (C) 1998 Academic Press.