title: Differential requirements for alpha4 integrins during fetal and adult hematopoiesis.
abstract: Mice chimeric for the expression of alpha4 integrins were used to dissect the roles of these receptors in development and traffic of lymphoid and myeloid cells. During fetal life, T cell development is alpha4 independent, but after birth further production of T cells becomes alpha4 dependent. Precursors for both T and B cells require alpha4 integrins for normal development within the bone marrow. In contrast, monocytes and natural killer cells can develop normally without alpha4 integrins. Thus, there are lymphocyte-specific, developmentally regulated requirements for alpha4 integrins in hematopoiesis in the bone marrow. We also show that alpha4 integrins are essential for T cell homing to Peyer's patches, but not to other secondary lymphoid organs, including spleen, lymph nodes, and intestinal epithelium.
authors.affiliation: Howard Hughes Medical Institute, Cambridge, Massachusetts 02139, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Arroyo
authors.forename: J T
authors.initials: JT
authors.lastname: Yang
authors.forename: H
authors.initials: H
authors.lastname: Rayburn
authors.forename: R O
authors.initials: RO
authors.lastname: Hynes
mesh_terms: D000367:Age Factors; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology*; D001402:B-Lymphocytes / Q000737:chemistry / Q000166:cytology / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002465:Cell Movement / Q000276:immunology*; D002678:Chimera; D005333:Fetus / Q000502:physiology; D005434:Flow Cytometry; D015870:Gene Expression / Q000276:immunology; D006410:Hematopoiesis / Q000276:immunology*; D039441:Integrin alpha4; D016023:Integrins / Q000235:genetics / Q000276:immunology*; D007694:Killer Cells, Natural / Q000737:chemistry / Q000166:cytology / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009000:Monocytes / Q000737:chemistry / Q000166:cytology / Q000276:immunology; D009154:Mutation / Q000276:immunology; D010581:Peyer's Patches / Q000166:cytology; D016133:Polymerase Chain Reaction; D013234:Stem Cells / Q000737:chemistry / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000737:chemistry / Q000166:cytology* / Q000276:immunology
chemical_list: D015703:Antigens, CD; D016023:Integrins; D039441:Integrin alpha4