Immunological Assays

A B S T R A C T Cell-mediated and humoral immilune responses of mutant diabetic db+/db+ mice were evaluated using in vivo and in vitro immunological assays. When compared to lean, nondiabetic db+/m+ or m+/m+ mice, db+/db+ mice demonstrated markedly altered in vivo immune responses characterized by a significantly diminished ability to reject allogeneic skin grafts, a markedly diminished capacity to generate cytotoxic cells after sensitization with allogeneic EL-4 lymphoma cells and a significantly enhanced plaque-forming cell response to sheep erythrocytes. In contrast, spleen cells from db+/db+ mice demonistrated only miniimal alterations in in vitro responses to mitogenis and allogeneic cells and no alteration in their capacity to generate an in vitro plaquie-forming cell response. The spleenis and thymuses of db+/db+ mice weighed significantly less thani organ.s friom db+/mn+ mice. In additioni, thymuses from db+/db+ mice demonistrated a marked deficiency in in vivo [1251] UdR uptake. These data suggest that the altered metabolic status of the diabetic host influiences immunie function in vivo possibly due to abnormiial funliction of lymphocyte subpopulations.