Passive transfer of insulitis from the "BB" rat to the nude mouse.

The "BB" rat spontaneously develops insulitis, and an insulin-dependent diabetic syndrome like that in man. Lymphocytes were isolated from blood and spleen of newly-detected "BB" diabetic rats and injected intraperitoneally (IP) into athymic nude mice. Of 72 mice receiving single injections 37% showed insulitis, with 13% of islets examined being affected, and mean intensity of 1.9 +/- 0.3 (on a scale of 0 to 3). In 12 mice receiving 3 separate injections of pooled blood and spleen lymphocytes, 58% showed insulitis, with 17% of islets affected, and mean intensity 2.5 +/- 0.3. Of 45 control mice either untreated, injected IP with saline, or injected with cells from nondiabetic control rats, only one showed mild insulitis. No random or post IP glucose hyperglycemia was observed. Thus, 1) passive transfer of insulitis has been achieved; 2) insulitis may be present without glucoregulatory disturbances; 3) the pancreatic B cell need not display abnormal membrane structure for it to be susceptible to involvement in the cell-mediated immune process; and 4) detailed studies are required to define the relationship of administered lymphocytes to the observed pathology.