title: Adult murine hematopoiesis can proceed without beta1 and beta7 integrins.
abstract: The function of alpha4beta1 and alpha4beta7 integrins in hematopoiesis is controversial. While some experimental evidence suggests a crucial role for these integrins in retention and expansion of progenitor cells and lymphopoiesis, others report a less important role in hematopoiesis. Using mice with a deletion of the beta1 and the beta7 integrin genes restricted to the hematopoietic system we show here that alpha4beta1 and alpha4beta7 integrins are not essential for differentiation of lymphocytes or myelocytes. However, beta1beta7 mutant mice displayed a transient increase of colony-forming unit (CFU-C) progenitors in the bone marrow and, after phenylhydrazine-induced anemia, a decreased number of splenic erythroid colony-forming units in culture (CFUe's). Array gene expression analysis of CD4(+)CD8(+) double-positive (DP) and CD4(-)CD8(-) double-negative (DN) thymocytes and CD19(+) and CD4(+) splenocytes did not provide any evidence for a compensatory mechanism explaining the mild phenotype. These data show that alpha4beta1 and alpha4beta7 are not required for blood cell differentiation, although in their absence alterations in numbers and distribution of progenitor cells were observed.
authors.affiliation: Max Planck Institute of Biochemistry, Department of Molecular Medicine, Am Klopferspitz 18, 82152 Martinsried, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Bungartz
authors.forename: Sebastian
authors.initials: S
authors.lastname: Stiller
authors.forename: Martina
authors.initials: M
authors.lastname: Bauer
authors.forename: Werner
authors.initials: W
authors.lastname: Müller
authors.forename: Angela
authors.initials: A
authors.lastname: Schippers
authors.forename: Norbert
authors.initials: N
authors.lastname: Wagner
authors.forename: Reinhard
authors.initials: R
authors.lastname: Fässler
authors.forename: Cord
authors.initials: C
authors.lastname: Brakebusch
mesh_terms: D000743:Anemia, Hemolytic / Q000097:blood / Q000473:pathology; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000502:physiology; D002465:Cell Movement; D003114:Colony-Forming Units Assay; D004920:Erythropoiesis; D015870:Gene Expression; D006410:Hematopoiesis / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology; D039641:Integrin beta Chains / Q000235:genetics / Q000502:physiology*; D019012:Integrin beta1 / Q000235:genetics / Q000502:physiology*; D038041:Lymphopoiesis; D051379:Mice; D018345:Mice, Knockout; D038042:Myelopoiesis; D013601:T-Lymphocytes / Q000166:cytology / Q000502:physiology
chemical_list: D039641:Integrin beta Chains; D019012:Integrin beta1; C091368:integrin beta7