Classification of human lymphocytes and monocytes with the OK series of monoclonal antibodies.

Membrane antigens expressed by either peripheral blood B cells, monocytes, or activated T cells have been identified by monoclonal antisera. OKB1, OKB2, OKB4, and OKB7 react with all or most circulating Smlg+ cells and have differential effects on the generation of plaque forming cells in the reverse hemolytic plaque assay. Of the new monocyte antibodies, OKM5 displays more restricted specificity for monocytes than the previously described OKM1, whereas OKM3 and OKM6 define monocyte subsets. In addition, several new T-cell "activation" antigens have been identified that differ in their expression depending on the nature of the triggering stimulus. These reagents should be of diagnostic and perhaps therapeutic utility.