title: Interleukin-7 activates intestinal lymphocytes.
abstract: Human intestinal lymphocytes, particularly intraepithelial lymphocytes, proliferate minimally to some agents, like mitogens and stimuli of the CD3 pathway. This in vitro finding may be due, in part, to a loss of factors found in vivo. Three T-cell growth factors, IL-7, IL-9, and IL-12, were tested for their ability to stimulate the proliferation of intestinal lymphocytes. Both intraepithelial lymphocytes and lamina propria lymphocytes proliferated more vigorously to IL-7 than to IL-9 or IL-12, and only IL-7 increased stimulation through the CD3 pathway. The IL-7-induced response was IL-2-dependent: IL-2 receptors appeared on both intestinal lymphocyte types, and antibody to the IL-2 receptor blocked IL-7-induced proliferation. Both CD4+ and CD8+ T-cell subsets responded to this cytokine as shown by phenotype-depletion experiments and constancy in the CD4/CD8 ratios after culture with IL-7. In addition, the T-cell receptor alpha beta and gamma delta subsets responded equally well to IL-7. This newly described selective proliferative response of intestinal lymphocytes to IL-7, but not to IL-9 or IL-12, requires no preactivation and may enhance growth in vivo.
authors.affiliation: Department of Medicine, UMDNJ-Robert Wood Johnson Medical School, New Brunswick 08903-0019, USA.
authors.forename: M
authors.initials: M
authors.lastname: Bilenker
authors.forename: A I
authors.initials: AI
authors.lastname: Roberts
authors.forename: R E
authors.initials: RE
authors.lastname: Brolin
authors.forename: E C
authors.initials: EC
authors.lastname: Ebert
mesh_terms: D000906:Antibodies / Q000494:pharmacology; D017252:CD3 Complex / Q000276:immunology; D016516:CD4-CD8 Ratio; D004847:Epithelial Cells; D004848:Epithelium / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D018664:Interleukin-12 / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D015851:Interleukin-7 / Q000494:pharmacology*; D016906:Interleukin-9 / Q000494:pharmacology; D007422:Intestines / Q000166:cytology* / Q000276:immunology; D008213:Lymphocyte Activation; D015375:Receptors, Interleukin-2 / Q000276:immunology
chemical_list: D000906:Antibodies; D017252:CD3 Complex; D007376:Interleukin-2; D015851:Interleukin-7; D016906:Interleukin-9; D015375:Receptors, Interleukin-2; D018664:Interleukin-12