Tetherins From Equine,Donkey,Human And Rhesus Inhibit Equine Infectious Anemia Virus Release

Host restriction factors are components of the innate immune response and interfere with different stages of thevirus life cycle. There are four main classes of restriction factors that are effective against retroviruses:cytidinedeaminases such as APOBEC3G (apolipoprotein B mRNAediting enzyme3G), which induces lethalhypermutations in the retroviral genome; TRIM5α (tripartite motif protein5α) proteins, which restrict the incomingretroviral capsid; and Tetherin (also known as BST-2, CD317, or HM1.24), SAMHD1（sterile α motif domain andHD domain-containing protein1）. Restriction factors comprise an important layer of host defense to fight againstviral infection, they can help to control virus spread and to prevent crossspecies transmission of viral pathogens.Thehost restriction factor Tetherin was recently discovered to block the release of enveloped viruses from the cell surface,which is regarded as a novel antiviral mechanism induced by interferon. This study focuses on host restriction factorsTetherin and EIAV,To identify the biologic function of Tetherin,Tetherin gene was inserted into eukaryoticexpression vector pEF4/myc-His B to construct recombinant plasmid of pHF-eq.Tetherin, pHF-don.Tetherin,pHF-hu.Tetherin, pHF-mac.Tetherin. The four plasmids of Tetherin were co-transfected with infectious clone ofequine infectious anemia virus (EIAV) into293T cell and Hela cell, the results showed Tetherin protein was able tosignificantly block the release of EIAV VLPs on cell surface.Tetherin is a cell surface membrane protein with anunusual topology, consisting of a short N-terminal cytoplasmic tail (CT), a transmembrane domain (TM), anextracellular coiled-coil and a glycophosphatidyl inositol anchor(GPI) at the C-terminusThe CT and GPI anchor arethe reason why Tetherin can retain viral particles on the cell surface.Equine Infectious Anemia Virus (EIAV) related with human immunodeficiency virus,is an RNA virus, amember of the Retroviridae family and of the lentivirus genus. This study focuses on host restriction factors Tetherinand EIAV, it’s important not only for the research of innate immune of equine research, but also provide somereference value for HIV research.Through comparing the function of Tetherin of four species(horse, donkey, hunman and rhesus)between each other,it is found that Tetherin protein broadly inhibits release of retrovirus by tethering the virus particles on plasma mem-brane. This study enriched equine limiting factor research and provided evidence for Tetherin block the release ofenveloped viruses from the cell surface.