title: A role for S1P and S1P1 in immature-B cell egress from mouse bone marrow.
abstract: B lymphocyte egress from secondary lymphoid organs requires sphingosine-1-phosphate (S1P) and S1P receptor-1 (S1P1). However, whether S1P contributes to immature-B cell egress from the bone marrow (BM) has not been fully assessed. Here we report that in S1P- and S1P1-conditionally deficient mice, the number of immature-B cells in the BM parenchyma increased, while it decreased in the blood. Moreover, a slower rate of bromodeoxyuridine incorporation suggested immature-B cells spent longer in the BM of mice in which S1P1-S1P signaling was genetically or pharmacologically impaired. Transgenic expression of S1P1 in developing B cells was sufficient to mobilize pro- and pre-B cells from the BM. We conclude that the S1P1-S1P pathway contributes to egress of immature-B cells from BM, and that this mechanism is partially redundant with other undefined pathways.
authors.affiliation: Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California, United States of America. Joao.Pereira@ucsf.edu
authors.forename: João Pedro
authors.initials: JP
authors.lastname: Pereira
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Jason G
authors.initials: JG
authors.lastname: Cyster
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D001853:Bone Marrow / Q000378:metabolism*; D001973:Bromodeoxyuridine / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects; D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D005260:Female; D000068876:Fingolimod Hydrochloride; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008246:Lysophospholipids / Q000378:metabolism / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D018345:Mice, Knockout; D008822:Mice, Transgenic; D054448:Precursor Cells, B-Lymphoid / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D011409:Propylene Glycols / Q000494:pharmacology; D049349:Receptors, Lysosphingolipid / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology
chemical_list: D007166:Immunosuppressive Agents; D008246:Lysophospholipids; D011409:Propylene Glycols; D049349:Receptors, Lysosphingolipid; C060506:sphingosine 1-phosphate; D001973:Bromodeoxyuridine; D000068876:Fingolimod Hydrochloride; D013110:Sphingosine