title: Intracellular antibody-mediated immunity and the role of TRIM21.
abstract: Protection against bacterial and viral pathogens by antibodies has always been thought to end at the cell surface. Once inside the cell, a pathogen was understood to be safe from humoral immunity. However, it has now been found that antibodies can routinely enter cells attached to viral particles and mediate an intracellular immune response. Antibody-coated virions are detected inside the cell by means of an intracellular antibody receptor, TRIM21, which directs their degradation by recruitment of the ubiquitin-proteasome system. In this article we assess how this discovery alters our view of the way in which antibodies neutralise viral infection. We also consider the antiviral function of TRIM21 in the context of its other reported roles in immune signalling and autoimmunity. Finally, we discuss the conceptual implications of intracellular antibody immunity and how it alters our view of the discrete separation of extracellular and intracellular environments.
authors: MRC Laboratory of Molecular Biology, PNAC Division, Cambridge, UK.
authors: William A
authors: WA
authors: McEwan
authors: Donna L
authors: DL
authors: Mallery
authors: David A
authors: DA
authors: Rhodes
authors: John
authors: J
authors: Trowsdale
authors: Leo C
authors: LC
authors: James
mesh_terms: D000256:Adenoviridae / Q000276:immunology; D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology*; D000936:Antigen-Antibody Complex / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D003600:Cytosol / Q000276:immunology / Q000821:virology; D006801:Humans; D056724:Immunity, Humoral; D051379:Mice; D046988:Proteasome Endopeptidase Complex / Q000276:immunology; D012261:Ribonucleoproteins / Q000276:immunology*; D015398:Signal Transduction; D054875:Ubiquitination; D053585:Virus Attachment; D053586:Virus Internalization; D000099207:SS-A Antigen
chemical_list: D057134:Antibodies, Neutralizing; D000936:Antigen-Antibody Complex; D001324:Autoantigens; D046988:Proteasome Endopeptidase Complex; D012261:Ribonucleoproteins; D000099207:SS-A Antigen