title: A large subpopulation of lymphocytes with T helper phenotype (Leu-3/T4+) exhibits the property of binding to NK cell targets and granular lymphocyte morphology.
abstract: A discrete subpopulation of lymphocytes sharing several phenotypic characteristics with natural killer (NK) cells was identified within the circulating pool of human lymphocytes that bear the T helper marker Leu-3. This Leu-3+ subpopulation of cells formed cell conjugates with the NK target cell lines K562 and MOLT-4, but did not bind to mouse myeloma and hybridoma cell lines that are insensitive to NK cells. The Leu-3+ lymphocytes binding to NK cell targets contained cytoplasmic granules similar in ultrastructure and cytochemistry to those previously defined in granular lymphocytes with NK function, except that the granules in Leu-3+ cells were smaller and fewer in number. Unlike classical NK cells, however, the granular Leu-3+ cells did not kill the target cells to which they bound, even after treatment with interferon. The proportion of granular Leu-3+ cells with the capacity to bind to NK cell targets was approximately 7% at birth and increased to approximately 21% of the Leu-3+ cells in adults. These observations suggest the possibility of a lineal relationship between the granular Leu-3+ cells and granular Leu-3- cells with NK capability.
authors.forename: A
authors.initials: A
authors.lastname: Velardi
authors.forename: C E
authors.initials: CE
authors.lastname: Grossi
authors.forename: M D
authors.initials: MD
authors.lastname: Cooper
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis; D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000032:analysis*; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins; D005455:Fluorescent Antibody Technique; D005456:Fluorescent Dyes; D005819:Genetic Markers; D006801:Humans; D007124:Immunoenzyme Techniques; D007694:Killer Cells, Natural / Q000276:immunology*; D015470:Leukemia, Myeloid, Acute; D008214:Lymphocytes / Q000276:immunology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008875:Middle Aged; D010641:Phenotype; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D013861:Thiocyanates
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D005452:Fluoresceins; D005456:Fluorescent Dyes; D005819:Genetic Markers; D013861:Thiocyanates; D000135:Acid Phosphatase; D016650:Fluorescein-5-isothiocyanate