title: Inhibition of the Nef regulatory protein of HIV-1 by a single-domain antibody.
abstract: The Nef protein of HIV-1 is important for AIDS pathogenesis, but it is not targeted by current antiviral strategies. Here, we describe a single-domain antibody (sdAb) that binds to HIV-1 Nef with a high affinity (K(d) = 2 × 10(-9)M) and inhibited critical biologic activities of Nef both in vitro and in vivo. First, it interfered with the CD4 down-regulation activity of a broad panel of nef alleles through inhibition of the Nef effects on CD4 internalization from the cell surface. Second, it was able to interfere with the association of Nef with the cellular p21-activated kinase 2 as well as with the resulting inhibitory effect of Nef on actin remodeling. Third, it counteracted the Nef-dependent enhancement of virion infectivity and inhibited the positive effect of Nef on virus replication in peripheral blood mononuclear cells. Fourth, anti-Nef sdAb rescued Nef-mediated thymic CD4(+) T-cell maturation defects and peripheral CD4(+) T-cell activation in the CD4C/HIV-1(Nef) transgenic mouse model. Because all these Nef functions have been implicated in Nef effects on pathogenesis, this anti-Nef sdAb may represent an efficient tool to elucidate the molecular functions of Nef in the virus life cycle and could now help to develop new strategies for the control of AIDS.
authors.affiliation: Institut Cochin, CNRS UMR8104, Université Paris Descartes, 27 Rue du Faubourg Saint-Jacques,Paris, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Bouchet
authors.forename: Stéphane E
authors.initials: SE
authors.lastname: Basmaciogullari
authors.forename: Pavel
authors.initials: P
authors.lastname: Chrobak
authors.forename: Bettina
authors.initials: B
authors.lastname: Stolp
authors.forename: Nathalie
authors.initials: N
authors.lastname: Bouchard
authors.forename: Oliver T
authors.initials: OT
authors.lastname: Fackler
authors.forename: Patrick
authors.initials: P
authors.lastname: Chames
authors.forename: Paul
authors.initials: P
authors.lastname: Jolicoeur
authors.forename: Serge
authors.initials: S
authors.lastname: Benichou
authors.forename: Daniel
authors.initials: D
authors.lastname: Baty
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000628:therapy; D000818:Animals; D002161:Camelids, New World / Q000276:immunology; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D015483:HIV Antibodies / Q000737:chemistry / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D019169:Jurkat Cells; D051379:Mice; D008809:Mice, Inbred C3H; D008822:Mice, Transgenic; D058990:Molecular Targeted Therapy / Q000379:methods; D011485:Protein Binding; D017434:Protein Structure, Tertiary / Q000502:physiology; D057127:Single-Chain Antibodies / Q000737:chemistry / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology*; D054311:nef Gene Products, Human Immunodeficiency Virus / Q000037:antagonists & inhibitors* / Q000276:immunology* / Q000378:metabolism
chemical_list: D015483:HIV Antibodies; D057127:Single-Chain Antibodies; D054311:nef Gene Products, Human Immunodeficiency Virus; C514837:nef protein, Human immunodeficiency virus 1