title: Escherichia coli and Pseudomonas aeruginosa induce expansion of V delta 2 cells in adult peripheral blood, but of V delta 1 cells in cord blood.
abstract: Human peripheral blood T cells proliferate in response to Escherichia coli and Pseudomonas aeruginosa. We observed that during the first few days after stimulation a large percentage of the responding PBMC were gamma delta T cells. In our study we characterized the early T cell responses of freshly isolated adult and newborn PBMC to soluble preparations of heat-killed E. coli and P. aeruginosa. Specimens from all healthy adults tested showed intense proliferation in response to both bacterial preparations; at 6 days, the responding cells were mainly T cell blasts, of which high percentages (up to 80%) were gamma delta T cells, most expressing V delta 2/V gamma 9. All newborn blood specimens tested also showed T cell proliferative responses, which included a marked expansion of gamma delta T cells, mainly of the V delta 1 subset. Populations of purified V delta 1 and V delta 2 T cells were obtained from adult PBMC following stimulation with E. coli; both subsets proliferated upon rechallenge with the bacterial preparations. Protease treatment of the bacterial preparations did not appreciably affect their ability to induce expansion of gamma delta T cells in either adult or cord blood, indicating that the stimulatory components were not proteins. The response of gamma delta T cells from newborns indicates that prior exposure to bacterial products is not necessary and suggests that gamma delta T cells are important elements in natural immunity to these extracellular organisms.
authors: Department of Pathology, Harvard Medical School, Massachusetts General Hospital, Charlestown 02129, USA.
authors: C M
authors: CM
authors: Kersten
authors: R T
authors: RT
authors: McCluskey
authors: L A
authors: LA
authors: Boyle
authors: J T
authors: JT
authors: Kurnick
mesh_terms: D000328:Adult; D000375:Aging / Q000097:blood / Q000276:immunology*; D001769:Blood / Q000276:immunology*; D019286:Endopeptidase K; D004926:Escherichia coli / Q000276:immunology*; D005312:Fetal Blood / Q000276:immunology*; D016694:Gene Rearrangement, delta-Chain T-Cell Antigen Receptor; D006801:Humans; D007113:Immunity, Innate; D016130:Immunophenotyping; D007231:Infant, Newborn; D008213:Lymphocyte Activation; D011550:Pseudomonas aeruginosa / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics*; D012697:Serine Endopeptidases / Q000494:pharmacology; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta; D012697:Serine Endopeptidases; D019286:Endopeptidase K