title: The role of BST2/tetherin in feline retrovirus infection.
abstract: Pathogenic retroviral infections of mammals have induced the evolution of cellular anti-viral restriction factors and have shaped their biological activities. This intrinsic immunity plays an important role in controlling viral replication and imposes a barrier to viral cross-species transmission. Well-studied examples of such host restriction factors are TRIM5α, an E3 ubiquitin ligase that binds incoming retroviral capsids in the cytoplasm via its C-terminal PRY/SPRY (B30.2) domain and targets them for proteasomal degradation, and APOBEC3 proteins, cytidine deaminases that induce hypermutation and impair viral reverse transcription. Tetherin (BST-2, CD317) is an interferon-inducible transmembrane protein that potently inhibits the release of nascent retrovirus particles in single-cycle replication assays. However, whether the primary biological activity of tetherin in vivo is that of a restriction factor remains uncertain as recent studies on human tetherin suggest that it is unable to prevent spreading infection of human immunodeficiency virus type 1 (HIV-1). The feline tetherin homologue resembles human tetherin in amino acid sequence, protein topology and anti-viral activity. Transiently expressed feline tetherin displays potent inhibition of feline immunodeficiency virus (FIV) and HIV-1 particle release. However, stable ectopic expression of feline tetherin in a range of feline cell lines has no inhibitory effect on the growth of either primary or cell culture-adapted strains of FIV. By comparing and contrasting the activities of the felid and primate tetherins against their respective immunodeficiency-causing lentiviruses we may gain insight into the contribution of tetherins to the control of lentiviral replication and the evolution of lentiviral virulence.
authors.affiliation: Retrovirus Research Laboratory, MRC - University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bearsden Road, Glasgow G611QH, United Kingdom. i.dietrich.1@research.gla.ac.uk
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dietrich
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: Hosie
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Willett
mesh_terms: D000818:Animals; D002415:Cats / Q000821:virology; D016181:Feline Acquired Immunodeficiency Syndrome / Q000276:immunology / Q000503:physiopathology / Q000821:virology*; D007113:Immunity, Innate / Q000502:physiology; D016089:Immunodeficiency Virus, Feline / Q000502:physiology*; D014779:Virus Replication / Q000502:physiology