title: Defective T cell responsiveness in chronic lymphocytic leukemia: analysis of activation events.
abstract: Chronic lymphocytic leukemia (CLL) is a B cell disorder in which major T cell proliferative defects are present. We investigated the nature of this deficit by studying several parameters known to be crucial in normal T cell proliferative response to mitogen. Purified peripheral blood T cells from B-CLL patients were analyzed for the presence of T3 antigen. We observed that CLL T cells have a direct correlation between levels of T3 membrane antigen and proliferative response to mitogen. The appearance of activation antigens (transferrin, HLA-DR, and interleukin 2 [IL 2] receptor) was normal in CLL T cells post-mitogen exposure. Despite the normal presentation of IL 2 receptor on CLL T cell membrane, there was decreased production of IL 2 by CLL patients (v controls) (39.6 +/- 10.2 cells per milliliter v 64.6 +/- 11.0 cells per milliliter). Finally, we were able partially, but not fully, to reconstitute CLL T proliferative response to mitogen by adding purified exogenous IL 2. These findings suggest that CLL T cells have multiple defects that may impact on their proliferative potential. Further insight into these deficits may result in strategies that will facilitate immunologic restoration in T cells of these patients.
authors.forename: N E
authors.initials: NE
authors.lastname: Kay
authors.forename: M E
authors.initials: ME
authors.lastname: Kaplan
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D007945:Leukemia, Lymphoid / Q000276:immunology*; D008213:Lymphocyte Activation; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D007376:Interleukin-2; D010835:Phytohemagglutinins