title: The immunologic functions of the neonatal Fc receptor for IgG.
abstract: Careful regulation of the body's immunoglobulin G (IgG) and albumin concentrations is necessitated by the importance of their respective functions. As such, the neonatal Fc receptor (FcRn), as a single receptor, is capable of regulating both of these molecules and has become an important focus of investigation. In addition to these essential protection functions, FcRn possesses a number of other functions that are equally as critical and are increasingly coming to attention. During the very first stages of life, FcRn mediates the passive transfer of IgG from mother to offspring both before and after birth. In the adult, FcRn regulates the persistence of both IgG and albumin in the serum as well as the movement of IgG, and any bound cargo, between different compartments of the body via transcytosis across polarized cells. FcRn is also expressed by hematopoietic cells; consistent with this, FcRn regulates MHC class II presentation and MHC class I cross-presentation by dendritic cells. As such, FcRn plays an important role in immune surveillance throughout adult life. The increasing appreciation for FcRn in both homeostatic and pathological conditions is generating an intense interest in the potential for therapeutic modulation of FcRn binding to IgG and albumin.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
authors.forename: Timo
authors.initials: T
authors.lastname: Rath
authors.forename: Timothy T
authors.initials: TT
authors.lastname: Kuo
authors.forename: Kristi
authors.initials: K
authors.lastname: Baker
authors.forename: Shuo-Wang
authors.initials: SW
authors.lastname: Qiao
authors.forename: Kanna
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Masaru
authors.initials: M
authors.lastname: Yoshida
authors.forename: Derry
authors.initials: D
authors.lastname: Roopenian
authors.forename: Edda
authors.initials: E
authors.lastname: Fiebiger
authors.forename: Wayne I
authors.initials: WI
authors.lastname: Lencer
authors.forename: Richard S
authors.initials: RS
authors.lastname: Blumberg
mesh_terms: D000418:Albumins / Q000378:metabolism; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D000941:Antigens / Q000276:immunology / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology* / Q000378:metabolism*; D009154:Mutation; D011485:Protein Binding; D015202:Protein Engineering; D021381:Protein Transport / Q000276:immunology; D011961:Receptors, Fc / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D017452:Receptors, IgG / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
chemical_list: D000418:Albumins; D000941:Antigens; D015395:Histocompatibility Antigens Class I; D007074:Immunoglobulin G; D011961:Receptors, Fc; D017452:Receptors, IgG; C100688:Fc receptor, neonatal