title: Sphingosine-1-phosphate and lymphocyte egress from lymphoid organs.
abstract: Much has been learned about how cells enter lymphoid tissues. But how do they leave? Sphingosine-1-phosphate (S1P) has emerged over the past decade as a central mediator of lymphocyte egress. In this review, we summarize the current understanding of how S1P promotes exit from the secondary lymphoid organs and thymus. We review what is known about additional requirements for emigration and summarize the mostly distinct requirements for exit from the bone marrow. Egress from lymphoid organs is limited during immune responses, and we examine how this regulation works. There is accumulating evidence for roles of S1P in directing immune cell behavior within lymphoid tissues. How such actions can fit together with the egress-promoting role of S1P is discussed. Finally, we examine current understanding of how FTY720, a drug that targets S1P receptors and is approved for the treatment of multiple sclerosis, causes immune suppression.
authors.affiliation: Howard Hughes Medical Institute and Department of Microbiology and Immunology, University of California, San Francisco, California 94143-0414, USA. Jason.Cyster@ucsf.edu
authors.forename: Jason G
authors.initials: JG
authors.lastname: Cyster
authors.forename: Susan R
authors.initials: SR
authors.lastname: Schwab
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D000068876:Fingolimod Hydrochloride; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008198:Lymph Nodes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D008221:Lymphoid Tissue / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D008246:Lysophospholipids / Q000276:immunology / Q000378:metabolism*; D008954:Models, Biological; D011409:Propylene Glycols / Q000494:pharmacology; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D013950:Thymus Gland / Q000187:drug effects / Q000276:immunology / Q000378:metabolism
chemical_list: D007166:Immunosuppressive Agents; D008246:Lysophospholipids; D011409:Propylene Glycols; C060506:sphingosine 1-phosphate; D000068876:Fingolimod Hydrochloride; D013110:Sphingosine