Inhibition by Trypanosoma cruzi of interferon-gamma production by mitogen-stimulated mouse spleen cells.
Infection by Trypanosoma cruzi is accompanied by severe immunosuppression during the acute period. As part of our studies, to define the alterations caused by Trypanosoma cruzi in lymphocyte function, we examined in this work the interferon-gamma (IFN-gamma)-producing capacity of mitogen-stimulated mouse spleen and human peripheral blood mononuclear cells in the presence or absence of blood forms of the parasite. Co-culture of phytohaemagglutinin- or concanavalin A-stimulated spleen cells from normal mice with T. cruzi significantly decreased the levels of IFN-gamma activity found in the supernatants at 48 or 72 h. In contrast, human peripheral blood mononuclear cells, though suppressed by T. cruzi in their capacity to proliferate upon mitogenic stimulation, showed no significant decrease in IFN-gamma production. The addition of exogenous IFN-gamma did not reverse the suppressive effect of T. cruzi on either mouse or human cells. These results revealed, for the first time, the ability of T. cruzi to impair IFN-gamma production by activated mouse lymphocytes. The lack of restoration by exogenous IFN-gamma suggested that the reduced levels of this lymphokine were not, at least by themselves, the causative factor of reduced lymphoproliferation.
Beltz
L A
LA
Sonnenfeld
G
G
Kierszenbaum
F
F
D000818:Animals; D002478:Cells, Cultured; D007371:Interferon-gamma / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D013154:Spleen / Q000276:immunology*; D014349:Trypanosoma cruzi / Q000276:immunology*
D007371:Interferon-gamma