title: Host cell-derived complement control proteins CD55 and CD59 are incorporated into the virions of two unrelated enveloped viruses. Human T cell leukemia/lymphoma virus type I (HTLV-I) and human cytomegalovirus (HCMV).
abstract: The current study was undertaken to determine whether the human T cell leukemia/lymphoma oncovirus type I (HTLV-I) and the herpesvirus human cytomegalovirus (HCM) incorporate host cell-derived C regulatory proteins. Our experiments showed that both CD59 and CD55 were associated with the external membrane of HTLV-I derived from MT2 cells, since virus could be captured by mAbs to these proteins, and antisera to CD55 and CD59 induced C-mediated lysis of HTLV-I virions. Additionally, both CD55 and CD59 were detected by immunoblot analysis of purified HTLV-I. Purified HCMV produced in human foreskin fibroblasts (HFF) also contained both CD55 and CD59, as detected by immunoblot analysis. However, treatment with anti-CD55, but not anti-CD59, reduced the HCMV infectious titer in the presence of C. Additional studies determined whether HTLV-I-associated CD55 and CD59 participated in the resistance of the virus to C-mediated lysis. Treatment of virus with phosphatidylinositol-specific phospholipase C (PI-PLC), which removes glycosylphosphatidylinositol-anchored CD55 and CD59, increased the sensitivity of HTLV-I to C-mediated destruction in the presence of anti-HTLV-I Abs. Reconstitution of PI-PLC-treated virus with purified CD55 and CD59 restored resistance to C. These experiments show that HTLV-I and HCMV acquire C control proteins from host cells. Together with our previous experiments showing that both CD55 and CD59 are present on HIV-1, these studies demonstrate a mechanism by which a variety of enveloped viruses may acquire resistance to C-mediated destruction.
authors.affiliation: Department of Immunology/Microbiology, Rush Presbyterian-St. Luke's Medical Center, Chicago, IL 60612, USA.
authors.forename: G T
authors.initials: GT
authors.lastname: Spear
authors.forename: N S
authors.initials: NS
authors.lastname: Lurain
authors.forename: C J
authors.initials: CJ
authors.lastname: Parker
authors.forename: M
authors.initials: M
authors.lastname: Ghassemi
authors.forename: G H
authors.initials: GH
authors.lastname: Payne
authors.forename: M
authors.initials: M
authors.lastname: Saifuddin
mesh_terms: D018958:CD55 Antigens / Q000032:analysis / Q000378:metabolism* / Q000502:physiology; D018957:CD59 Antigens / Q000032:analysis / Q000378:metabolism* / Q000502:physiology; D002460:Cell Line; D003169:Complement Inactivator Proteins / Q000032:analysis / Q000276:immunology* / Q000378:metabolism; D003587:Cytomegalovirus / Q000276:immunology* / Q000378:metabolism; D015368:Human T-lymphotropic virus 1 / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D014759:Viral Envelope Proteins / Q000032:analysis / Q000276:immunology* / Q000378:metabolism; D014771:Virion / Q000276:immunology / Q000378:metabolism*
chemical_list: D018958:CD55 Antigens; D018957:CD59 Antigens; D003169:Complement Inactivator Proteins; D014759:Viral Envelope Proteins