THE APPEARANCE OF UNUSUAL PHENOTYPIC CELLS (CD4(-1(+) CLASS-II+) IN THE LIVER OF (NZW-X-BXSB) F1-MICE IS POSSIBLY AN ANIMAL-MODEL FOR AUTOIMMUNE HEPATITIS() MAC)

The male (NZW x BXSB)F-1 (W/BF1) mouse, a murine model for autoimmune diseases, shows hepatosplenomegaly with lymphoid cell infiltration in the liver by 20 weeks of age. The majority of infiltrating cells are T cells, B cells and plasma cells, as seen in autoimmune hepatitis. Tog ether with the increase in serum glutamate pyruvate transaminase (GPT) levels, anti-dsDNA antibody (Ab) and circulating immune complex (CIC) levels increase with age. These findings are compatible with these of autoimmune hepatitis in humans. In addition, a unique finding in this mouse is the accumulation of CD4(+) Mac-1(+) Class II+ cells in the s inusoidal space. The cells have the capacity to proliferate and differ entiate into macrophages in vitro, indicating that they are the precur sors oi macrophages. This W/BF1, mouse provides a useful tool for not only analyzing the pathogenesis of autoimmune hepatitis but also estab lishing a new therapeutic strategy for it. In addition, we discuss the significance of the appearance of abnormal cells in autoimmune-prone mice.