title: The synthetic peptide derived from the NH2-terminal extracellular region of an orphan G protein-coupled receptor, GPR1, preferentially inhibits infection of X4 HIV-1.
abstract: Several G protein-coupled receptors (GPCRs) serve as co-receptors for entry of human immunodeficiency virus type 1 (HIV-1) into target cells. Here we report that a synthetic peptide derived from the NH2-terminal extracellular region of an orphan GPCR, GPR1 (GPR1ntP-(1-27); MEDLEETLFEEFENYSYDLDYYSLESC), inhibited infection of not only an HIV-1 variant that uses GPR1 as a co-receptor, but also X4, R5, and R5X4 viruses. Among these HIV-1 strains tested, viruses that can utilize CXCR4 as their co-receptors were preferentially inhibited. Inhibition of early steps in X4 virus replication was also detected in the primary human peripheral blood lymphocytes. GPR1ntP-(1-27) directly interacted with recombinant X4 envelope glycoprotein (rgp120). This interaction was neither inhibited nor enhanced by the soluble CD4 (sCD4) but inhibited by the anti-third variable (V3) loop-specific monoclonal antibody and heparin known to bind to the V3 loop. Although the conformational changes in gp120, including the V3 loop, have been reported to be required for its interaction with a co-receptor after binding of gp120 to CD4, it has also been reported that the V3 loop is already exposed on the surface of virions before interaction with CD4. We found that GPR1ntP-(1-27) blocked binding of virus to the cells, and this peptide equally bound to rgp120 in the presence or absence of sCD4. Because we detected the binding of GPR1ntP-(1-27) to the highly purified virions even in the absence of sCD4, GPR1ntP-(1-27) probably recognized the V3 loop exposed on the virions, and this interaction was responsible for the anti-HIV-1 activity of GPR1ntP-(1-27).
authors.affiliation: Department of Virology and Preventive Medicine, Gunma University Graduate School of Medicine, Showa-machi, Maebashi, Gunma 371-8511, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Jinno-Oue
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Shimizu
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Soda
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tanaka
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ohtsuki
authors.forename: Dai
authors.initials: D
authors.lastname: Kurosaki
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Hiroo
authors.initials: H
authors.lastname: Hoshino
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000378:metabolism; D015658:HIV Infections / Q000378:metabolism / Q000517:prevention & control; D015497:HIV-1 / Q000378:metabolism / Q000472:pathogenicity*; D006801:Humans; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology; D014771:Virion / Q000378:metabolism
chemical_list: C504821:GPR1 protein, human; D015699:HIV Envelope Protein gp120; D010455:Peptides; D043562:Receptors, G-Protein-Coupled