Sheep red cell binding to human lymphocytes treated with neuraminidase; enhancement of T cell binding and identification of a subpopulation of B cells.

Neuraminidase treatment of normal human lymphocytes enhances their capacity to form SRBC rosettes; more red cells are bound and the rosettes are more stable. Under these conditions approximately 90% of peripheral blood lymphocytes form rosettes. In addition to the effects on T cells, another population of lymphocytes which possess surface immunoglobulin and have the Fc receptor acquire the rosette-forming property after neuraminidase. This subpopulation of 'B' cells represents approximately half of the lymphocytes with surface immunoglobulin but is not found among the leukemic lymphocytes of patients with chronic lymphocytic leukemia. Electron microscope observations indicate close approximation and intimate association of the red cell and lymphocyte membranes after neuraminidase.