Hu Ly-M3--a human leukocyte antigen.

A monoclonal antibody, 5-4.8, was produced against human peripheral blood lymphocytes and it appears to be leukocyte-specific in that it reacts with a common determinant (called Hu Ly-m3) present on the peripheral blood T, B and null lymphocytes of 40 individuals. The antibody also reacts with thymocytes, spleen cells, and bone marrow cells (30%) and weakly with granulocytes and platelets--but not with heart, liver, or kidney. Affinity to lentil-lectin and molecular weight analysis demonstrated that Hu Ly-m3 is a glycoprotein consisting of a single chain of 47,000 daltons which is not HLA because it is not present on all cells; because it is present on the surface of the phenotypically HLA- Daudi cell line; and because soluble HLA antigens did not inhibit the binding of the 5-4.8 antibody.