title: The classical and regulatory functions of C1q in immunity and autoimmunity.
abstract: A classical function of C1q is to bind immune complexes and initiate complement activation producing membrane lytic complexes, opsonins and anaphylatoxins. This classical pathway of complement activation is also elicited when C1q binds some other ligands. Besides complement activation, C1q also regulates cell differentiation, adhesion, migration, activation and survival. C1q deficiency is associated with autoimmunity as well as increased susceptibility to infections. In this article, we discuss the basic properties of C1q, its expression, and classical and regulatory functions.
authors.affiliation: Department of Microbiology, Yong Loo Lin School of Medicine and 2NUS Immunology Program, National University of Singapore, Blk MD4, 5 Science Drive 2, Singapore 117597. miclujh@nus.edu.sg
authors.forename: Jin Hua
authors.initials: JH
authors.lastname: Lu
authors.forename: Boon King
authors.initials: BK
authors.lastname: Teh
authors.forename: Lin da
authors.initials: Ld
authors.lastname: Wang
authors.forename: Yi Nan
authors.initials: YN
authors.lastname: Wang
authors.forename: Yen Seah
authors.initials: YS
authors.lastname: Tan
authors.forename: Min Chern
authors.initials: MC
authors.lastname: Lai
authors.forename: Kenneth B M
authors.initials: KB
authors.lastname: Reid
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D000936:Antigen-Antibody Complex / Q000378:metabolism; D017209:Apoptosis; D015551:Autoimmunity; D002097:C-Reactive Protein / Q000276:immunology / Q000378:metabolism; D002454:Cell Differentiation; D003167:Complement Activation; D015922:Complement C1q / Q000172:deficiency / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D003171:Complement Pathway, Classical; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007107:Immune System / Q000166:cytology / Q000276:immunology; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D010587:Phagocytosis; D011951:Receptors, Complement / Q000276:immunology / Q000378:metabolism
chemical_list: D000936:Antigen-Antibody Complex; D011951:Receptors, Complement; D015922:Complement C1q; D002097:C-Reactive Protein