title: NK cytotoxicity against CD4+ T cells during HIV-1 infection: a gp41 peptide induces the expression of an NKp44 ligand.
abstract: HIV infection leads to a state of chronic immune activation and progressive deterioration in immune function, manifested most recognizably by the progressive depletion of CD4+ T cells. A substantial percentage of natural killer (NK) cells from patients with HIV infection are activated and express the natural cytotoxicity receptor (NCR) NKp44. Here we show that a cellular ligand for NKp44 (NKp44L) is expressed during HIV-1 infection and is correlated with both the progression of CD4+ T cell depletion and the increase of viral load. CD4+ T cells expressing this ligand are highly sensitive to the NK lysis activity mediated by NKp44+ NK cells. The expression of NKp44L is induced by the linear motif NH2-SWSNKS-COOH of the HIV-1 envelope gp41 protein. This highly conserved motif appears critical to the sharp increase in NK lysis of CD4+ T cells from HIV-infected patients. These studies strongly suggest that induction of NKp44L plays a key role in the lysis of CD4+ T cells by activated NK cells in HIV infection and consequently provide a framework for considering how HIV-1 may use NK cell immune surveillance to trigger CD4+ T cells. Understanding this mechanism may help to develop future therapeutic strategies and vaccines against HIV-1 infection.
authors.affiliation: Laboratoire d'Immunologie Cellulaire et Tissulaire, Institut National de la Santé et de la Recherche Médicale U543, Hôpital Pitié-Salpétrière, 75013 Paris, France. vincent.vieillard@chups.jussieu.fr
authors.forename: Vincent
authors.initials: V
authors.lastname: Vieillard
authors.forename: Jack L
authors.initials: JL
authors.lastname: Strominger
authors.forename: Patrice
authors.initials: P
authors.lastname: Debré
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D015700:HIV Envelope Protein gp41 / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology*; D008024:Ligands; D051379:Mice; D055629:Natural Cytotoxicity Triggering Receptor 2; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D011971:Receptors, Immunologic / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D015700:HIV Envelope Protein gp41; D008024:Ligands; C112837:NCR2 protein, human; D055629:Natural Cytotoxicity Triggering Receptor 2; D010446:Peptide Fragments; D011971:Receptors, Immunologic