title: Proliferative and cytokine responses by human newborn T cells stimulated with staphylococcal enterotoxin B.
abstract: Staphylococcal enterotoxins are potentially valuable tools for investigating the development of T-cell responses because in experimental animals they can elicit either T-cell activation and proliferation or tolerance. Previous studies indicate that human T cells bearing the CD45RA phenotype (which account for the majority of newborn T cells) respond poorly to stimulation by staphylococcal enterotoxin B (SEB) compared with mature T cells from adult blood. The present studies show that the mean frequency of newborn T cells that proliferated in limiting dilution cultures stimulated by SEB was 1:3135, with a 1SD range of 3153-4191 compared with a mean of 1:493 and range of 120-1737 for adult T cells. Neither indomethacin nor the nitric oxide synthesis inhibitor, n-arginine methyl ester, increased SEB responses by newborn cells, arguing against down-regulation of the newborn response by prostaglandin or nitric oxide. Naive (CD45RA+) T cells from adult blood had a responder cell frequency to SEB similar to that of the newborn cells. IL-2 production by newborn cells was delayed compared with adult cells but was equivalent after 3 d of culture. Production of gamma-interferon and IL-4 was greater by adult than newborn cells. Our results indicate that a subset of CD45RA+ cells that is activated by SEB can mature to make IL-4 or gamma-interferon after 3-5 d. The limiting dilution assay results provide a quantitative basis for proliferation by naive T cells against which responses by T cells from healthy and premature newborns can be compared.
authors.affiliation: Department of Pediatrics, University of Colorado School of Medicine, Denver 80262.
authors.forename: A
authors.initials: A
authors.lastname: Hayward
authors.forename: M
authors.initials: M
authors.lastname: Cosyns
mesh_terms: D000328:Adult; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D016207:Cytokines / Q000096:biosynthesis*; D004768:Enterotoxins / Q000276:immunology*; D006801:Humans; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D007231:Infant, Newborn; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D017493:Leukocyte Common Antigens; D008213:Lymphocyte Activation / Q000187:drug effects; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors; D013211:Staphylococcus aureus; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology*
chemical_list: D016207:Cytokines; D004768:Enterotoxins; D007376:Interleukin-2; D015847:Interleukin-4; D009569:Nitric Oxide; C031818:enterotoxin B, staphylococcal; D007371:Interferon-gamma; D001120:Arginine; D017493:Leukocyte Common Antigens; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin