LEUKOCYTES OF PATIENTS WITH SCHISTOSOMA-MANSONI RESPOND WITH A TH2 PATTERN OF CYTOKINE PRODUCTION TO MITOGEN OR EGG ANTIGENS BUT WITH A TH0PATTERN TO WORM ANTIGENS

Cytokine responses of peripheral blood mononuclear cells from humans i nfected with Schistosoma mansoni were assessed. By ELISA and ELISPOT, persons with acute and hepatosplenic infections produced higher levels of interleukin (IL)-4 and IL-5 and higher frequencies of IL-4-produci ng cells in response to mitogen than did uninfected persons. In contra st, mitogen-induced production of the Th1 cytokine interferon-gamma (I FN-gamma) did not differ from that of uninfected controls. Upon stimul ation with egg antigens, many patients responded with elevated IL-4 mR NA levels but displayed no appreciable increases in Th1 (i.e., IFN-gam ma and IL-2) cytokine transcripts. Nevertheless, in cells stimulated w ith adult worm antigen, a more mixed Th0-type response was observed wi th production of both Th1 and Th2 cytokines. These results support pre vious findings in laboratory mice that schistosome infection results i n increased production of Th2 cytokines. Unlike mice, infected humans do not display a generalized down-modulation in Th1 responses but inst ead show a selective deficiency in IFN-gamma and usually IL-2 response s to egg antigens.