title: TCR usage and functional capabilities of human gamma delta T cells at birth.
abstract: Little is known about the gamma delta T cells in human neonatal umbilical cord blood. To compare neonatal cord blood and adult blood gamma delta T cells, we studied the V gamma and V delta gene segment usage in these populations by flow cytometry, and we derived cord blood gamma delta T cell clones to determine their functional capabilities. Unlike adult blood gamma delta T cells that predominantly express V gamma 2V delta 2 TCRs, neonatal cord blood gamma delta T cells expressed diverse V gamma and V delta gene segments paired in a variety of combinations rarely observed in adults. gamma delta T cell clones derived from neonatal cord blood similarly expressed a diverse array of TCRs. These cord blood-derived gamma delta T cell clones had weak cytolytic activity when assayed for K562 tumor cell killing, lectin-mediated cytolysis, and redirected cytolysis. They also expressed lower levels of the CD2, LFA-1, and CD45RO cell surface receptors as compared with strongly cytolytic adult gamma delta T cell clones. These properties of the cord blood-derived gamma delta T cell clones, weak cytotoxic activity and low adhesion molecule expression, were similar to the properties of the CD4+ subset of adult gamma delta T cells. Thus, neonatal gamma delta T cells are functionally different from the majority of adult gamma delta T cells and display a distinct TCR repertoire and accessory molecule profile.
authors.affiliation: Department of Rheumatology and Immunology, Brigham and Women's Hospital, Boston, MA 02115.
authors.forename: C T
authors.initials: CT
authors.lastname: Morita
authors.forename: C M
authors.initials: CM
authors.lastname: Parker
authors.forename: M B
authors.initials: MB
authors.lastname: Brenner
authors.forename: H
authors.initials: H
authors.lastname: Band
mesh_terms: D000328:Adult; D000942:Antigens, Bacterial / Q000276:immunology; D018801:CD2 Antigens / Q000096:biosynthesis; D002460:Cell Line; D002999:Clone Cells; D003601:Cytotoxicity Tests, Immunologic; D005312:Fetal Blood / Q000166:cytology* / Q000276:immunology; D006801:Humans; D007231:Infant, Newborn / Q000276:immunology*; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1 / Q000096:biosynthesis; D009161:Mycobacterium / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D018801:CD2 Antigens; D016169:Lymphocyte Function-Associated Antigen-1; D016692:Receptors, Antigen, T-Cell, gamma-delta; D017493:Leukocyte Common Antigens