B-CLL cells express true endogenous E receptor after culture with T-cells and mitogens

Abstract

Culture studies of peripheral blood mononuclear cells from 7 typical cases of B-cell chronic lymphatic leukemia (CLL) [human] showed that, in the presence of PHA [phytohemagglutinin] or Con A [concanavalin A] and .gtoreq. 20% autologous or allogeneic T cells, CLL cells express true sheep erythrocyte (E) receptor after 2-5 d [days], but fail to stain with a panel of anti-T cell sera. In contrast to similarly cultured hairy cells (HC), the cultured CLL cells continue to express L chain-restricted surface immunoglobulin (SIg) and show no change in their morphology. The continued SIg positivity and staining with a panel of monoclonal antibodies indicated that the high proportion of E+ cells could not be attributed to the outgrowth of normal T cells or to mitogen-induced non-specific stickiness. Repeated addition of supernatants from cultured T cells caused no phenotypic changes and therefore excluded the possibility of shedding and passive acquisition of E receptor. The points of similarity and difference between the responses of CLL cells and HC cultured in a like manner are briefly considered in relation to the possible lineages of these 2 cell types.