Anti-red blood cell autoantibody transgenic mice: murine model of autoimmune hemolytic anemia.

We established an anti-red blood cell (RBC) autoantibody transgenic mouse line, in which almost all B cells were deleted in the periphery. A small number of B-1 cells, however, escaped from deletion, survived and expanded in the peritoneal cavity and the gut, because of the absence of RBC. The activation of B-1 cells by enteric bacteria induced autoimmune hemolytic anemia (AIHA). In turn, AIHA was cured by elimination of peritoneal B-1 cells. This Tg mouse line is useful for revealing the generation and activation of B-1 cells, and for clarifying the physiological and pathological roles of B-1 cells.