IN-VITRO PROLIFERATION AND PRODUCTION OF GAMMA-INTERFERON BY MURINE CD4(-PARVUM ANTIGEN() CELLS IN RESPONSE TO CRYPTOSPORIDIUM)

Spleen cells from mice immunized with Cryptosporidium parvum were enri ched for T cells by passage over an affinity chromatography column. Th e proliferative response of these cells was >2-fold higher than the re sponse of unenriched cells. T-enriched cells were enriched further for either CD4(+) cells or CD8(+) cells. The proliferative response of CD 4-enriched cells was >4-fold higher than the response by unenriched ce lls. CD8(+) cells were essentially nonresponsive to C. parvum antigen. Culture supernatant fractions from these variously enriched splenocyt e populations were assayed for cytokine production. Cultures containin g CD4(+) cells produced gamma interferon and interleukin-2 following i ncubation with C. parvum antigen. None of the cultures produced interl eukin-4. Production of gamma interferon and interleukin-2, but not int erleukin-4, is characteristic of the previously described Th1 helper c ell subset. Our data indicate that a subset of murine lymphocytes cons istent with the Th1 helper cell phenotype proliferates following in vi tro stimulation with C. parvum antigen.