Urinary bladder carcinogenesis in the dog: preliminary studies on cellular immunity.

The immunologic status of dogs undergoing bladder carcinogenesis with 4-amino-biphenyl and normal littermate controls is being evaluated. Studies using blastogenic transformation, nonimmune cytotoxic reactions, and rosette formation have revealed that dogs possess lymphocytes that have some properties similar to those of B and T cells of other species. Since tumors are now just appearing and hence are not yet available for specific immunologic determinations, the assessments had to be limited for the present to other types of antigens and mitogens (yeast, red blood cells and plant lectins). No major changes in reactions of cells from the carcinogenized animals have yet been observed during the preneoplastic phase as measured by phagocytosis, migration inhibition, or cytotoxicity tests, although a trend to lower blastogenic responses was noted. It yet remains to be seen whether lower lymphocyte responses to mitogens in carcinogenized dogs are of prognostic value for the early detection of tumors of the bladder.