Human lymphocytes bearing both receptors for complement components and SRBC

Abstract

Employing a mixed rosette method, the proportion of peripheral lymphocytes bearing both complement receptors and the capacity to bind to sheep erythrocytes (D-lymphocytes) was determined in relation to lymphocyte with easily detectable B- or T-cell markers in healthy persons and leukemic patients. A range of 0.5–8% D-lymphocytes was found to be present in peripheral blood of healthy persons. A reduced proportion of peripheral D-lymphocytes was observed in about 30% of 17 patients with lymphocytic leukemia. The surface markers of D-lymphocytes were investigated with preparations enriched with D-lymphocytes obtained with a BSA gradient centrifugation method. It was demonstrated with an immunofluorescent technique that normal D-lymphocytes lack detactable surface immunoglobulins. Another type of doubly-marked lymphocyte which possess both affinities for IgG and sheep erythrocytes may lack complement receptors, the relationship of these cells with D-lymphocytes remains to be further determined. Cells from a lymphosblastoid line possessing both receptors for complement and SRBC were found to have some common membrane markers of normal D-lymphocytes. Aside from the B- and T-populations, the doubly-marked lymphocytes may be important small subpopulations of human lymphocytes.