Cross-reacting anti-monkey lymphocyte antisera: A simplified immunofluorescence approach for detecting human T and B lymphocytes

A new method for detecting human T and B cells is described. This approach utilizes a direct immunofluorescence assay and heterologous antisera prepared against purified populations of monkey T cells and B cells. These anti-monkey lymphocyte reagents reacted specifically with human T cells and B cells, respectively, after relatively few absorptions. The distribution of human T and B cells in thymus, spleen, lymph node, and blood was similar to that previously described for mice and rats. In addition, these antisera identified certain lymphocyte subpopulations not previously detected using conventional assays. These have tentatively been characterized as a nonrosetting T-cell population in bone marrow and a population of neoplastic B lymphocytes in certain leukemic patients that express little or no membrane surface immunoglobulin. Further definition of lymphocyte subpopulations detected by these heteroantisera may delineate new information about their function and maturation and may lead to the development of clinically useful diagnostic reagents.