title: In vitro proliferation and cloning of CD3- CD16+ cells from human thymocyte precursors.
abstract: Purified CD3-4- thymocytes were obtained by depletion of CD3+ and CD4+ cells from fresh thymocyte suspensions. 5-15% of these cells were found to express CD16 antigen, while other natural killer (NK) cell markers were virtually absent. Double fluorescence analysis revealed that 20-40% of thymic CD16+ cells coexpressed CD1, while approximately half were cyCD3+. When cultured in the presence of peripheral blood lymphocytes and H9 leukemia cell line as a source of irradiated feeder cells and interleukin 2 (IL-2), CD3-4- thymocytes underwent extensive proliferation. In addition, after 1-2 wk of culture, 30-50% of these cells were found to express CD16 surface antigen. Cloning under limiting dilution conditions of either CD3-4- or CD3-4-16- thymocytes in the presence of irradiated H9 cells resulted in large proportions (approximately 50%) of CD16+ clones. On the basis of the expression of surface CD16 and/or cyCD3 antigen, clones could be grouped in the following subsets: CD16+ cyCD3+; CD16+ cyCD3-; CD16- cyCD3+; and CD16- cyCD3-. All clones expressed CD56 surface antigen, displayed a strong cytolytic activity against NK sensitive (K562) and NK-resistant (M14) target cells, and produced IFN-gamma and tumor necrosis factor, but not IL-2. Similar to peripheral NK cells, thymic CD16+ cells expressed transcripts for CD16 and for CD3 epsilon (Biassoni, R., S. Ferrini, I. Prigione, A. Moretta, and E.O. Long, 1988. J. Immunol. 140:1685.) and zeta chains (Anderson, P., M. Caligiuri, J. Ritz, and S.F. Schlossman. 1989. Nature [Lond.]. 341:159). Therefore, it appears that cells that are phenotypically and functionally similar to CD3- CD16+ NK cells may arise from immature thymocytes.
authors.affiliation: Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
authors.forename: M C
authors.initials: MC
authors.lastname: Mingari
authors.forename: A
authors.initials: A
authors.lastname: Poggi
authors.forename: R
authors.initials: R
authors.lastname: Biassoni
authors.forename: R
authors.initials: R
authors.lastname: Bellomo
authors.forename: E
authors.initials: E
authors.lastname: Ciccone
authors.forename: N
authors.initials: N
authors.lastname: Pella
authors.forename: L
authors.initials: L
authors.lastname: Morelli
authors.forename: S
authors.initials: S
authors.lastname: Verdiani
authors.forename: A
authors.initials: A
authors.lastname: Moretta
authors.forename: L
authors.initials: L
authors.lastname: Moretta
mesh_terms: D015703:Antigens, CD / Q000235:genetics*; D000943:Antigens, Differentiation / Q000032:analysis / Q000235:genetics*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis / Q000235:genetics*; D015152:Blotting, Northern; D017252:CD3 Complex; D002460:Cell Line; D002478:Cells, Cultured; D002999:Clone Cells; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D006801:Humans; D008213:Lymphocyte Activation; D008212:Lymphocyte Depletion; D010641:Phenotype; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D011948:Receptors, Antigen, T-Cell / Q000032:analysis / Q000235:genetics*; D011961:Receptors, Fc / Q000032:analysis / Q000235:genetics*; D017452:Receptors, IgG; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology*; D014158:Transcription, Genetic
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D011948:Receptors, Antigen, T-Cell; D011961:Receptors, Fc; D017452:Receptors, IgG; D012313:RNA