In vitro proliferation and production of gamma interferon by murine CD4+ cells in response to Cryptosporidium parvum antigen.

Spleen cells from mice immunized with Cryptosporidium parvum were enriched for T cells by passage over an affinity chromatography column. The proliferative response of these cells was > 2-fold higher than the response of unenriched cells. T-enriched cells were enriched further for either CD4+ cells or CD8+ cells. The proliferative response of CD4-enriched cells was > 4-fold higher than the response by unenriched cells. CD8+ cells were essentially nonresponsive to C. parvum antigen. Culture supernatant fractions from these variously enriched splenocyte populations were assayed for cytokine production. Cultures containing CD4+ cells produced gamma interferon and interleukin-2 following incubation with C. parvum antigen. None of the cultures produced interleukin-4. Production of gamma interferon and interleukin-2, but not interleukin-4, is characteristic of the previously described Th1 helper cell subset. Our data indicate that a subset of murine lymphocytes consistent with the Th1 helper cell phenotype proliferates following in vitro stimulation with C. parvum antigen.