Immunological Potential of the in vitro Mixed Skin Cell-Leukocyte Reaction

THE mixed skin cell-leukocyte reaction (MSLR) is an in vitro reaction between dissociated skin cells and allogeneic peripheral blood leukocytes. It is similar in its immunological implications to the reaction between allogeneic leukocytes, commonly known as the mixed leukocyte reaction (MLR) or the mixed lymphocyte interaction (MLI). In the latter, immunological recognition between lymphocytes from genetically disparate donors can be detected and measured either by blastoid transformation, enhanced mitotic rate or induction of DNA synthesis^1–4. This system has been useful in the study of the transfer of transplantation immunity in vivo by lymphocytes sensitized in vitro⁵ and also in the identification of tissue incompatibility between donor and recipient^{6, 7}. In studies with inbred strains of rats the proliferative phase of the MLR has been shown to possess characteristics required for an immunological response; that is, selectivity and specificity^{8, 9}. Furthermore, mouse peripheral lymphocytes sensitized in mixed culture with allogeneic lymphocytes have been shown to engender immunospecific destruction of target cells¹⁰, an event which is directly associated with allograft rejection.