title: Unusual phenotype and function of an expanded subpopulation of T cells in patients with haemopoietic disorders.
abstract: We have studied two patients, one with red cell aplasia and the other with neutropenia. Both showed lymphocytosis. In both cases, 90-100% of E rosetting cells were T cells as defined by the monoclonal antibodies UCHT1 and OKT3. The majority of these cells also carried the OKT8 suppressor/cytotoxic marker and were HLA-DR- and Fc gamma R-positive. In spite of the similarity of this phenotype to that reported for suppressor cells, these cells failed to suppress pokeweed mitogen-induced polyclonal Ig synthesis. Cells from both patients also failed to respond significantly to Con A and PHA. They were, however, unable to suppress the Con A responses of normal donors although cells from one patient were able to suppress completely a normal PHA response. These results demonstrate the existence of a genuine subset of T cells with Fc gamma receptors but suggest that not all such cells have typical suppressor function.
mesh_terms: D000380:Agranulocytosis / Q000276:immunology*; D000741:Anemia, Aplastic / Q000276:immunology*; D000941:Antigens / Q000032:analysis; D005455:Fluorescent Antibody Technique; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D008934:Mitogens / Q000494:pharmacology; D009503:Neutropenia / Q000276:immunology*; D010641:Phenotype; D011961:Receptors, Fc / Q000032:analysis; D013601:T-Lymphocytes / Q000145:classification* / Q000276:immunology
chemical_list: D000941:Antigens; D007136:Immunoglobulins; D008934:Mitogens; D011961:Receptors, Fc