VALUE OF THE MIXED LYMPHOCYTE-REACTION IN DOGS AS A GENETIC ASSAY

For optimal use of the mixed lymphocyte reaction (MLR) for genetical and transplantation research in dogs, insight into the kinetics of the test is required. Therefore, cell-dose response curves were determined for various genetically defined cell mixtures. The optimal cell concentration was variable. No relation between genetic disparity and optimal cell concentration or responder/stimulator cell ratios was found. In time-course kinetics studies, earlier peak reactivity was observed with combinations from unrelated dogs than with those from related dogs. No difference was found when comparing related dogs with one haplotype difference with those with two haplotype differences. These results can be explained by the assumption that, in those combinations which differ for the major histocompatibility complex (MHC), non-MHC gene products can influence the outcome of the MLR. For a semiquantitative evaluation, a shorter culture period than that used for the determination of MLR negativity is preferred. Apparently, the combined use of different modifications of the test procedure for a single cell combination may increase the value of the test as a genetic tool. It remains to be seen whether such modifications will be sufficient for a complete evaluation of the complex genetic control of the MLR and its relevance to homotransplantation. © 1979 Springer-Verlag New York Inc.