title: Receptors for the third complement component on a proportion of large granular lymphocytes from human peripheral blood.
abstract: Large granular lymphocytes (LGL) are nonadherent cells with cytoplasmic azurophilic granules, avid receptors for the Fc portion of IgG, and a paranuclear localization of alpha-naphthyl acid esterase or acid phosphatase. LGL constitute the bulk of TG cells (cells with receptors for sheep erythrocytes and for IgG molecules) and null cells (non-T, non-B cells). In the present study we demonstrate that 20-33% of the circulating human LGL express receptors for the third complement component (C3R). When TG cell or null cell fractions from normal individuals or non-T cells from a patient with infantile agammaglobulinaemia (which contained almost exclusively LGL) were rosetted with erythrocytes coated with antibody and complement, a variable number of C3R-bearing cells were detected. Such cells were isolated and analysed further; the great majority of them displayed the cytochemical and ultrastructural features of LGL.
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000361:Agammaglobulinemia / Q000276:immunology; D002469:Cell Separation; D003176:Complement C3 / Q000378:metabolism*; D003594:Cytoplasmic Granules / Q000145:classification* / Q000648:ultrastructure; D006801:Humans; D008214:Lymphocytes / Q000145:classification / Q000378:metabolism* / Q000648:ultrastructure; D008215:Lymphocytes, Null / Q000378:metabolism; D009283:Naphthol AS D Esterase / Q000378:metabolism; D011951:Receptors, Complement; D013601:T-Lymphocytes / Q000145:classification / Q000378:metabolism
chemical_list: D003176:Complement C3; D011951:Receptors, Complement; D009283:Naphthol AS D Esterase; D000135:Acid Phosphatase