title: Expression of selectin-binding epitopes and cytokines by CD4+ T cells repopulating scid mice with colitis.
abstract: Recruitment into the gut of CD4+ T cells and their activation in the colonic lamina propria (LP) are key events in the development of colitis in scid mice reconstituted with CD4+ T cells from immunocompetent, congenic donor mice. This study investigated the expression of cytokines and selectin-binding epitopes by CD4+ T cells repopulating different tissues of the adoptive scid host. Cells from the inflamed colonic LP of transplanted scid mice produced high amounts of IL-12, IFN-gamma and TNF-alpha but only low amounts IL-4 and IL-10. Intracellular cytokine staining confirmed the presence of large numbers of IFN-gamma- and TNF-alpha-producing effector CD4+ T cells in the colonic LP of scid mice with colitis but also in non-inflamed tissues [spleen (S), peritoneal cavity (PC) and mesenteric lymph nodes (mLN)] of the adoptive host. Cells from these tissues furthermore produced large amounts of IL-12. Ligands for endothelial selectins are involved in recruiting T cells into inflamed tissues. We have analyzed the expression of selectin-binding epitopes on CD4+ T cells repopulating different tissues of the adoptive scid host. We found that a large fraction of CD4+ T cells from inflamed colonic LP and from non-inflamed PC, mLN and S expressed high levels of P- and E-selectin-binding epitopes (P-Lhi) in transplanted scid mice, but not in congenic, immunocompetent control mice. Although P-Lhi CD4+ T cells were enriched in IFN-gamma-producing subsets from most (but not all) tissues, we also found large numbers of in vivo generated P-Llo CD4+ T cells producing pro-inflammatory cytokines. This was in contrast to in vitro generated Th1 CD4+ T blasts that were almost exclusively P-Lhi. In this mouse model, production of Th1-type pro-inflammatory cytokines and expression of surface epitopes binding endothelial selectins are hence strikingly up-regulated in CD4+ T cells residing in inflamed and non-inflamed tissues during the development of colitis.
authors.affiliation: Department of Medical Microbiology, University of Ulm, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Thoma
authors.forename: K
authors.initials: K
authors.lastname: Bonhagen
authors.forename: D
authors.initials: D
authors.lastname: Vestweber
authors.forename: A
authors.initials: A
authors.lastname: Hamann
authors.forename: J
authors.initials: J
authors.lastname: Reimann
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003092:Colitis / Q000276:immunology* / Q000473:pathology; D016207:Cytokines / Q000096:biosynthesis*; D004729:Endothelium, Lymphatic / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000096:biosynthesis*; D005260:Female; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000276:immunology; D008024:Ligands; D008213:Lymphocyte Activation; D008221:Lymphoid Tissue / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D019007:P-Selectin / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D015854:Up-Regulation
chemical_list: D016207:Cytokines; D018984:Epitopes, T-Lymphocyte; D008024:Ligands; D019007:P-Selectin; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma