L3T4 effector cells in multiple organ-localized autoimmune disease in nude mice grafted with embryonic rat thymus

Rat thymic grafts reconstituted T cell functions of BALB/c nude (nu/nu) mice to a considerable degree, but multiple organ-localized autoimmune diseases such as oophoritis and thyroiditis generally developed. The effector cell population in this autoimmune model was studied by adoptive transfer of the lesions into syngeneic nude mice. The transfer activity was not diminished when spleen cells were incubated with antiserum against rat cell antigen and C, but the activity was completely vanished by incubation with anti-Thy-1.2 plus C, indicating that the effector cells are T cells of mouse origin. Elimination of the L3T4+ subset virtually abolished the transfer activity, whereas that of the Lyt-2+ subset did not, indicating that the effector cells are L3T4+. Positive selection experiments by FACS also demonstrated that L3T4+ cells, but not Lyt-2+ cells, were capable of inducing the lesion, confirming the results with depletion experiments described above.