title: New antigenic determinant (Sa) on human lymphocytes and phagocytes.
abstract: Presence of antigenic determinants reacting with homogeneous IgM/kappa cold agglutinin (CA) of a new specificity, tentatively called Sa, was investigated by bithermic cytotoxicity assay and by immunofluorescence. CA Sa killed on average 38% allogeneic peripheral blood lymphocytes (PBL) and up to 74% of autologous PBL. There was preferential kill of B-PBL compared to T-PBL. Some preference toward B cells was also noted using tonsillary B and T lymphocytes. Cytotoxic activity of CA Sa against chronic lymphocytic leukemia cells of B-type was almost equal to that of potent anti-I CA and much stronger than anti-i CA. Presence of additional B-cytotoxic factor in the serum was excluded by the use of red blood cell eluate composed solely of homogeneous CA. Thymocytes and helper-type T cells from a patient with T cell chronic lymphocytic leukemia were very susceptible to the cytotoxic action of Sa. CA Sa killed 39% of monocytes, but there was almost no kill of polymorphonuclear leukocytes. Lymphocytotoxicity of CA Sa was abolished by sialyllactose and was not influenced by I-active glycoproteins. Comparison of CA Sa to CA of other specificities showed marked differences, supporting the view that Sa has new, previously unrecognized specificity.
mesh_terms: D000368:Aged; D001402:B-Lymphocytes; D000939:Epitopes / Q000032:analysis*; D006801:Humans; D007945:Leukemia, Lymphoid / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D010586:Phagocytes / Q000276:immunology*; D013601:T-Lymphocytes
chemical_list: D000939:Epitopes