title: S100A9 protein is a novel ligand for the CD85j receptor and its interaction is implicated in the control of HIV-1 replication by NK cells.
abstract: BACKGROUND
  The reportedly broad expression of CD85j across different immune cell types suggests an importance for this molecule in the human immune system. Previous reports have shown that this receptor interacts with several HLA class-I molecules, as well as with some viral proteins. We have demonstrated that the subset of CD85j + Natural Killer (NK) cells efficiently controls human immunodeficiency virus type 1 (HIV-1) replication in monocyte-derived dendritic cells (MDDC) in vitro and this led us to hypothesize that the CD85j + NK cell-mediated anti-HIV activity in MDDC is specifically dependent on the interaction between the CD85j receptor and unknown non-HLA class-I ligand(s).
  
  
  RESULTS
  In this study, we focused our efforts on the identification of these non-described ligands for CD85j. We found that the CD85j receptor interacts with a calcium-binding proteins of the S100 family; namely, S100A9. We further demonstrated that HIV-1 infection of MDDC induces a modulation of S100A9 expression on surface of the MDDC, which potentially influences the anti-HIV-1 activity of human NK cells through a mechanism involving CD85j ligation. Additionally, we showed that stimulation of NK cells with exogenous S100A9 enhances the control of HIV-1 infection in CD4+ T cells.
  
  
  CONCLUSIONS
  Our data show that S100A9 protein, through ligation with CD85j, can stimulate the anti-HIV-1 activity of NK cells.
authors.forename: Vincent
authors.initials: V
authors.lastname: Arnold
authors.forename: Jean-Saville
authors.initials: JS
authors.lastname: Cummings
authors.forename: Uriel Y
authors.initials: UY
authors.lastname: Moreno-Nieves
authors.forename: Céline
authors.initials: C
authors.lastname: Didier
authors.forename: Adrien
authors.initials: A
authors.lastname: Gilbert
authors.forename: Françoise
authors.initials: F
authors.lastname: Barré-Sinoussi
authors.affiliation: Department of Virology, Unité de Régulation des Infections Rétrovirales, Institut Pasteur, 25 rue Dr Roux, Paris 75015, France. daniel.scott-algara@pasteur.fr.
authors.forename: Daniel
authors.initials: D
authors.lastname: Scott-Algara
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D040502:Calgranulin B / Q000378:metabolism*; D003713:Dendritic Cells / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000276:immunology* / Q000502:physiology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology* / Q000821:virology*; D000075362:Leukocyte Immunoglobulin-like Receptor B1; D011485:Protein Binding; D025941:Protein Interaction Mapping; D011971:Receptors, Immunologic / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D015703:Antigens, CD; D040502:Calgranulin B; C105299:LILRB1 protein, human; D000075362:Leukocyte Immunoglobulin-like Receptor B1; D011971:Receptors, Immunologic