title: Impaired phagocytosis in caveolin-1 deficient macrophages.
abstract: Caveolae are plasma membrane invaginations that function as important regulators of numerous cellular processes, including signal transduction, cholesterol trafficking, and endocytosis. Caveolin-1 (Cav-1) constitutes the main structural protein of caveolae membranes. Here, we report an in vivo increase in the number of apoptotic cells in the thymus and spleen of Cav-1 deficient mice, following whole-body gamma-irradiation. We demonstrate that this increase in apoptotic cells is not due to increased apoptosis in lymphocytes per se, which normally do not express Cav-1, but rather to the decreased phagocytic clearance of apoptotic cells by macrophages, which do express Cav-1. Utilizing in vitro phagocytosis assays of both apoptotic thymocytes and Escherichia coli K-12 BioParticles, we demonstrate that the loss of Cav-1 decreases the phagocytic ability of thioglycollate-elicited peritoneal macrophages. We suggest that impaired macrophage phagocytosis in Cav-1 knockout mice could have implications for altered innate immunity against pathogens, the regulation of inflammatory responses, and the development of autoimmune disease.
authors.affiliation: Department of Molecular Pharmacology & Medicine, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
authors.forename: Jiangwei
authors.initials: J
authors.lastname: Li
authors.forename: Alexis
authors.initials: A
authors.lastname: Scherl
authors.forename: Freddy
authors.initials: F
authors.lastname: Medina
authors.forename: Philippe G
authors.initials: PG
authors.lastname: Frank
authors.forename: Richard N
authors.initials: RN
authors.lastname: Kitsis
authors.forename: Herbert B
authors.initials: HB
authors.lastname: Tanowitz
authors.forename: Federica
authors.initials: F
authors.lastname: Sotgia
authors.forename: Michael P
authors.initials: MP
authors.lastname: Lisanti
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics / Q000276:immunology; D001327:Autoimmune Diseases / Q000235:genetics / Q000473:pathology; D051242:Caveolin 1 / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics*; D002478:Cells, Cultured; D007113:Immunity, Innate / Q000235:genetics; D007249:Inflammation / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D008264:Macrophages / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010587:Phagocytosis / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology / Q000382:microbiology / Q000473:pathology
chemical_list: D051242:Caveolin 1