title: CCR7 regulates lymphocyte egress and recirculation through body cavities.
abstract: T and B lymphocytes recirculate among blood, lymph, and extralymphoid tissues to ensure immune surveillance and the establishment of self-tolerance. The underlying mechanisms regulating homeostatic lymphocyte recirculation through body cavities are not fully understood. Here, we demonstrate that the homeostatic chemokine receptor CCR7 regulates homeostatic recirculation of lymphocytes through body cavities. CCR7 deficiency results in massive accumulation of CD4(+) and CD8(+) T cells and B-2 B cells in the peritoneal and pleural cavities. The increase in B-2 B and T lymphocytes is not associated with an altered maturation and/or activation status of these cells. Mechanistically, an increase in peritoneal lymphocyte numbers is caused by impaired egress of CCR7-deficient lymphocytes from body cavities. These results establish that CCR7 plays a crucial role in lymphocyte exit from the PerC.
authors.affiliation: Department of Tumor Genetics and Immunogenetics, Max-Delbrück-Center for Molecular Medicine, MDC, Berlin, Germany. uhoepken@mdc-berlin.de
authors.forename: Uta E
authors.initials: UE
authors.lastname: Höpken
authors.forename: Susann
authors.initials: S
authors.lastname: Winter
authors.forename: Ariel H
authors.initials: AH
authors.lastname: Achtman
authors.forename: Kerstin
authors.initials: K
authors.lastname: Krüger
authors.forename: Martin
authors.initials: M
authors.lastname: Lipp
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002465:Cell Movement / Q000276:immunology*; D006706:Homeostasis / Q000502:physiology; D007157:Immunologic Surveillance / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D010529:Peritoneal Cavity; D054400:Receptors, CCR7 / Q000235:genetics / Q000276:immunology*; D017634:Self Tolerance / Q000502:physiology
chemical_list: C515371:Ccr7 protein, mouse; D054400:Receptors, CCR7