USE OF HUMAN LEUKOCYTE-SPECIFIC MONOCLONAL-ANTIBODIES FOR CLINICALLY IMMUNOPHENOTYPING LYMPHOCYTES OF RHESUS-MONKEYS

The rhesus monkey (Macaca mulatta) is an important experimental animal frequently utilized for studies of infectious diseases, immunity, hem atopoiesis, and transplantation. Since the structure of cell surface m olecules is phylogenetically conserved, monoclonal antibodies raised a gainst human leukocyte antigens can sometimes recognize the homologous determinant on monkey leukocytes. To facilitate better utilization of this animal model, we tested 89 commercially available monoclonal ant ibodies which define 27 human cell surface antigens for reactivity wit h rhesus monkey PBL. Certain antigens which delineate clinical useful lymphocyte subsets such as CD2, CD4, CD8, CD14, CD16, CD20, and MHC cl ass II are apparently well conserved since most human cell-specific an tibodies identified the homologous cell subset in monkeys. However, ot her antigens such as CD3, CD19, CD45, and CD56 were identified infrequ ently by human cell-specific antibodies. FITC-modification of antibodi es which had no effect on their binding to human cells occasionally in hibited antibody binding to monkey cells. Nevertheless, an adequate nu mber of cross-reactive monoclonal antibodies was identified to allow g ating of lymphocytes for accurate flow cytometric analysis and quantit ation of the major lymphocyte subsets of the rhesus monkey. The T lymp hocyte subset distribution in blood and lymphoid tissue of rhesus monk eys was similar to man. However, the B subset was significantly larger in monkeys. The daily variation in absolute PBL subset size was marke d and found to be due mainly to daily fluctuations in total lymphocyte number. (C) 1994 Wiley-Liss, Inc.