title: A role for CCR9 in T lymphocyte development and migration.
abstract: CCR9 mediates chemotaxis in response to CCL25/thymus-expressed chemokine and is selectively expressed on T cells in the thymus and small intestine. To investigate the role of CCR9 in T cell development, the CCR9 gene was disrupted by homologous recombination. B cell development, thymic alphabeta-T cell development, and thymocyte selection appeared unimpaired in adult CCR9-deficient (CCR9(-/-)) mice. However, competitive transplantation experiments revealed that bone marrow from CCR9(-/-) mice was less efficient at repopulating the thymus of lethally irradiated Rag-1(-/-) mice than bone marrow from littermate CCR9(+/+) mice. CCR9(-/-) mice had increased numbers of peripheral gammadelta-T cells but reduced numbers of gammadeltaTCR(+) and CD8alphabeta(+)alphabetaTCR(+) intraepithelial lymphocytes in the small intestine. Thus, CCR9 plays an important, although not indispensable, role in regulating the development and/or migration of both alphabeta(-) and gammadelta(-) T lymphocytes.
authors.affiliation: Laboratory of Mammalian Genes and Development, National Institute of Child Health and Human Development, and Laboratory of Clinical Investigation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
authors.forename: Shoji
authors.initials: S
authors.lastname: Uehara
authors.forename: Alexander
authors.initials: A
authors.lastname: Grinberg
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Farber
authors.forename: Paul E
authors.initials: PE
authors.lastname: Love
mesh_terms: D000375:Aging / Q000235:genetics / Q000276:immunology; D000818:Animals; D016175:B-Lymphocyte Subsets / Q000166:cytology; D001854:Bone Marrow Cells / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte / Q000235:genetics / Q000276:immunology*; D003433:Crosses, Genetic; D006410:Hematopoiesis / Q000276:immunology; D007413:Intestinal Mucosa / Q000276:immunology / Q000378:metabolism; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009928:Organ Specificity / Q000235:genetics / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000096:biosynthesis; D054388:Receptors, CCR; D019707:Receptors, Chemokine / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D013950:Thymus Gland / Q000276:immunology / Q000473:pathology
chemical_list: C119309:CC chemokine receptor 9; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D054388:Receptors, CCR; D019707:Receptors, Chemokine