Schistosoma mekongi infection in man: cellular immune responses and modulating mechanisms
Barral-Netto, M.; Hofstetter, M.; Gustavo dos Santos, J.; Cheever, A.W.; Ottesen, E.A.
Clinical and Experimental Immunology 47(1): 65-73
1982
ISSN/ISBN: 0009-9104 PMID: 6212174 Document Number: 188036
Cell-mediated immune responses (CMI), as assessed by lymphocyte proliferation in vitro, were evaluated in 11 Laotian patients harbouring asymptomatic chronic infections by Schistosoma mekongi, a schistosome closely related to S. japonicum. When the mononuclear cells of these patients were cultured in autologous plasma, lymphocyte responses to schistosome antigens were essentially nil, not differing from those of unexposed North American controls. Specific lymphocyte proliferation, however, was seen both after the removal of mononuclear cells that were nylon-wool-adherent and after substitution of the autologous serum in the culture with normal AB serum. Our data suggest that the CMI responses of humans with chronic S. mekongi infections are 'modulated' by adherent suppressor cells and serum-suppressive factors, and that modulation of CMI supports the stable host-parasite relationship in a similar fashion to that described for chronic human Schistosoma mansoni infection.