Alloantigens defined by cytotoxic isoantisera prepared against peripheral rabbit lymphocytes

Seven lymphocytotoxic antisera were produced in rabbits by means of isoimmunization with purified peripheral lymphocytes. The phenotypic profile of the defined lymphocyte antigens was determined in a panel of 97 rabbits. The results indicated the existence of at least two major antigenic determinants. Further typing and cross-absorptions were performed with several of the lymphocytotoxic antisera in order to demonstrate monospecificity. The anti-3 antiserum was used to determine the distribution of the respective antigens in various rabbit organs. The highest concentration of the alloantigen was contained in the spleen, followed in descending order by the lymph nodes, lung, skin, kidney, heart and liver. Fat and red blood cells (rbc) contained no detectable antigen. A two-stage physical adherence column method was used to separate T-derived from B-derived lymphocytes and each fraction was tested for the alloantigen. Alloantigen was detected on both cell types. The fact that the anti-3 antiserum never killed more than 30% of the cells suggests that it could define a subpopulation of lymphocytes.