title: Identification of a novel CD56- lymphokine-activated killer cell precursor in cancer patients receiving recombinant interleukin 2.
abstract: Circulating lymphokine-activated killer (LAK) cell activity in cancer patients receiving recombinant interleukin 2 (rIL-2) therapy is confined to cells expressing the CD56- surface marker. However, CD56- cells from these patients but not normal individuals have been reported to exhibit LAK cytotoxicity only following in vitro activation with rIL-2. Studies were performed to document the existence of CD56- LAK precursor cells and to phenotypically characterize this population in patients receiving rIL-2 therapy using fluorescence-activated cell sorter-purified CD56- cell subsets. Initial studies confirmed that CD56- cells exhibit NK activity [20 +/- 7 (SE) LU/10(6) cells] but not LAK activity (0 +/- 0 LU/10(6) cells) when evaluated directly from peripheral blood of patients receiving rIL-2. CD56- cells from patients but not normal individuals developed significant LAK cytolytic activity against NK-resistant COLO 205 targets (16 +/- 3 LU/10(6) cells) when cultured for 3 days with 1500 units/ml rIL-2. The CD56- LAK precursor activity was confined to cells expressing a CD56-CD16+ phenotype and a large granular lymphocyte morphology; little or no NK or LAK precursor activity was detectable in CD56-CD5+ T-cells from patients. Phenotypic characterization of CD16+CD56- cells revealed that this population is uniformly CD11a+,CD18+, and CD38+ and is heterogeneous in its expression of CD11b, CD11c, and CD16/Leu 11c. These results indicate that rIL-2 administration induces enhanced LAK precursor activity in a novel population of CD5-CD16+CD56- cells.
authors.affiliation: Section of Hematology/Oncology, Loyola University Stritch School of Medicine, Maywood, Illinois 60153.
authors.forename: R S
authors.initials: RS
authors.lastname: McKenzie
authors.forename: P E
authors.initials: PE
authors.lastname: Simms
authors.forename: B A
authors.initials: BA
authors.lastname: Helfrich
authors.forename: R I
authors.initials: RI
authors.lastname: Fisher
authors.forename: T M
authors.initials: TM
authors.lastname: Ellis
mesh_terms: D015703:Antigens, CD / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D019002:CD56 Antigen; D002292:Carcinoma, Renal Cell / Q000097:blood* / Q000188:drug therapy; D002469:Cell Separation; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D006801:Humans; D007376:Interleukin-2 / Q000627:therapeutic use*; D007680:Kidney Neoplasms / Q000097:blood* / Q000188:drug therapy; D015979:Killer Cells, Lymphokine-Activated / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D016131:Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D008545:Melanoma / Q000097:blood* / Q000188:drug therapy; D010641:Phenotype; D017452:Receptors, IgG / Q000276:immunology; D011994:Recombinant Proteins / Q000627:therapeutic use
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D019002:CD56 Antigen; D007376:Interleukin-2; D017452:Receptors, IgG; D011994:Recombinant Proteins