Modification of T-cell proliferation and interleukin 2 production in mice infected with Trypanosoma cruzi.

Acute infection of mice with Trypanosoma cruzi results in severe immunodepression and the appearance of autoimmune symptoms. In vitro, concanavalin A-stimulated T cells from spleens of infected animals could neither produce nor respond to interleukin 2. Interleukin 2 production was not restored by addition of exogenous interleukin 1, and proliferative response to concanavalin A was not restored by exogenous interleukin 2. A population of Thy-1-negative cells in the spleen of infected animals was shown to suppress the concanavalin A proliferative response and, to a lesser extent, the production of interleukin 2. These and other symptoms of T. cruzi-infected mice are similar to the immune dysfunction of autoimmune lpr/lpr mice. These findings are discussed in relationship to the pathology of Chagas disease.