Isolation of specific antigen-reactive T-cell clones from nude (nu/nu) mice infected with Mesocestoides corti.

Infection of nude mice with Mesocestoides corti results in spleen enlargement, with a decrease in percentage positive, but overall increase in Thy-1 positive cells. A low frequency of both parasite antigen-specific and alloantigen-reactive T-cell clones were isolated from the spleen, mesenteric lymph nodes, peritoneal exudate and Peyer's patches. The T-cell clones from spleen were found to express the antigens Thy-1, Lyt-1 and Lyt-2; furthermore, after stimulation with antigen in the absence of exogenous T cell growth factor (IL-2), they produced normal levels of haemopoietic growth factor (IL-3), bone marrow proliferation activity and eosinophil differentiation activity. A higher proportion produced IL-2 compared to clones from normal mice. The isolation of antigen-specific T-cell clones showing normal T-cell characteristics from young nude mice adds weight to suggestions that exposure to antigen results in significant extra-thymic T-cell maturation.