Rapid loss of tolerance induced in weanling NZB and B-W F1 mice.

Young adult mice (30 to 43 days old) of autoimmune NZB and BIW F(1) strains failed to develop immunologic tolerance when treated with ultracentrifuged bovine gamma globulin and then challenged 12 days later. By contrast, weanling NZB and B/ W F(1) mice (18 to 25 days) as well as weanling C3H mice (16 to 19 days) became tolerant and had no serum antibody 12 days after challenge. The C3H mice remained unresponsive, but NZB and B! W F(1) mice produced antibody between days 27 and 41. The rapid loss of previously established tolerance to foreign antigens could have its parallel in the loss of tolerance to autoantigens with subsequent development of lupus nephritis and Coombs' positive hemolytic anemia in these animals.