Interleukin-2 allows in vivo induction of anti-erythrocyte autoantibody production in nude mice associated with the injection of rat erythrocytes.

Mice injected with rat red blood cells developed anti-erythrocyte autoantibodies detectable by a direct Coombs' test. Nude mice injected with rat red blood cells did not develop a Coombs-positive state, but nude mice injected with rat red blood cells plus the T cell helper factor, interleukin-2, produced autoantibodies to autologous mouse erythrocytes. The simultaneous injection of rat red blood cells and allogeneic spleen cells induced an early and vigorous autoantibody response in athymic nude mice as well as in euthymic control mice. These results are interpreted as indicating the possibility of an interleukin-2-stimulated in vivo differentiation (or clonal expansion) of helper T cells in nude mice in response to heterologous erythrocytes which could mediate an autoimmune B cell response.