title: Malignant clonal expansion of large granular lymphocytes with a Leu-11+, Leu-7- surface phenotype: in vitro responsiveness of malignant cells to recombinant human interleukin 2.
abstract: A 14-year-old Japanese female with neutropenia showed malignant proliferation of the large granular lymphocytes (LGLs). These LGLs were E rosette+ and Fc(IgG) receptor+ and therefore are referred to as T gamma lymphocytes. They were also Leu-11+ and OKT11+; however, they were clearly negative for Leu-7, OKT3, OKT8, OKM1, and HNK-1 antigens as well as for terminal deoxynucleotidyl transferase activity. Karyotype analysis revealed 47, XXX. The LGLs showed no rearrangement of T cell receptor C beta genes. The natural killer (NK) cell activity against K562 target cells was low, but was significantly augmented after stimulation by recombinant human interleukin 2 (IL 2) in contrast to minimal NK boosting by recombinant human gamma-interferon (gamma-IFN). Such a unique responsive ability to lymphokines was quite similar to that noted in fetal and cord blood cells. These LGLs also demonstrated a considerable increase in antibody-dependent cell-mediated cytotoxicity (ADCC) and lymphokine-activated killer (LAK) activity after a short incubation with IL 2. Although in a resting stage they showed no IL 2 receptor expression as examined by anti-Tac antibody, Tac antigen appeared after IL 2 treatment followed by a marked increase in 3H-thymidine incorporation and a remarkable production of gamma-IFN. To investigate the mechanism of neutropenia, in vitro IL 2-stimulated coculture studies of these cells with normal bone marrow cells were performed. Colony formation of myeloid progenitors (CFU-C) was significantly suppressed. In addition, the conditioned medium from IL 2-stimulated LGLs indicated a remarkable suppression of CFU-C. These results suggest that these LGLs with a Leu-11+, Leu-7- surface phenotype might belong to a unique subset of pre-NK cells that are functionally and phenotypically similar to those represented at any early stage of human ontogeny and that they strongly express Tac antigen under the influence of IL 2 administration, followed by remarkable cell proliferation and gamma-IFN production.
mesh_terms: D000293:Adolescent; D000920:Antibody-Dependent Cell Cytotoxicity; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D002454:Cell Differentiation; D003114:Colony-Forming Units Assay; D003602:Cytotoxicity, Immunologic; D005260:Female; D006410:Hematopoiesis; D006801:Humans; D007108:Immune Tolerance; D007113:Immunity, Innate; D007371:Interferon-gamma / Q000276:immunology; D007376:Interleukin-2 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000145:classification / Q000276:immunology / Q000473:pathology*; D007938:Leukemia / Q000473:pathology*; D008214:Lymphocytes / Q000145:classification / Q000276:immunology / Q000473:pathology*; D009503:Neutropenia / Q000276:immunology; D011961:Receptors, Fc / Q000032:analysis; D017452:Receptors, IgG; D011971:Receptors, Immunologic / Q000032:analysis; D015375:Receptors, Interleukin-2
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D007376:Interleukin-2; D011961:Receptors, Fc; D017452:Receptors, IgG; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D007371:Interferon-gamma