Murine lupus in the absence of αβ T cells

To investigate the possibility that non-αβ T cell-dependent mechanisms can induce systemic autoimmune disease, and to address the roles of αβ T cells in murine lupus, we analyzed lupus-prone MRL mice congenitally deficient in αβ T cells. Surprisingly, TCR-α(-/-) MRL mice developed several characteristics of human systemic lupus erythematosus, including hypergammaglobulinemia, autoantibodies against DNA and small nuclear ribonucleoproteins, and immune deposits in kidneys. These results, which contrast with past studies concluding that MRL autoimmunity requires CD4⁺ αβ T cells, demonstrate that non-αβ T cell-dependent mechanisms are capable of inducing lupus phenomena, and further suggest that MRL disease may consist of both αβ T cell-independent and αβ T cell-dependent mechanisms.