Identification of PVR (CD155) and Nectin-2 (CD112) as cell surface ligands for the human DNAM-1 (CD226) activating molecule

Cristina Bottino, Roberta Castriconi, Daniela Pende, Paola Rivera, Marina Nanni, Barbara Carnemolla, Claudia Cantoni, Jessica Grassi, Stefania Marcenaro, Nicolas Reymond, Massimo Vitale, Lorenzo Moretta, Marc Lopez, Alessandro Moretta

Research output: Contribution to journalArticle

Abstract

Human natural killer (NK) cells express a series of activating receptors and coreceptors that are involved in recognition and killing of target cells. In this study, in an attempt to identify the cellular ligands for such triggering surface molecules, mice were immunized with NK-susceptible target cells. On the basis of a functional screening, four mAbs were selected that induced a partial down-regulation of the NK-mediated cytotoxicity against the immunizing target cells. As revealed by biochemical analysis, three of such mAbs recognized molecules of ∼70 kD. The other mAb reacted with two distinct molecules of ∼65 and 60 kD, respectively. Protein purification followed by tryptic digestion and mass spectra analysis, allowed the identification of the 70 kD and the 65/60 kD molecules as PVR (CD155) and Nectin-2 δ/α (CD112), respectively. PVR-Fc and Nectin-2-Fc soluble hybrid molecules brightly stained COS-7 cells transfected with the DNAM-1 (CD226) construct, thus providing direct evidence that both PVR and Nectin-2 represent specific ligands for the DNAM-1 triggering receptor. Finally, the surface expression of PVR or Nectin-2 in cell transfectants resulted in DNAM-1-dependent enhancement of NK-mediated lysis of these target cells. This lysis was inhibited or even virtually abrogated upon mAb-mediated masking of DNAM-1 (on NK cells) or PVR or Nectin-2 ligands (on cell transfectants).

Original languageEnglish
Pages (from-to)557-567
Number of pages11
JournalJournal of Experimental Medicine
Volume198
Issue number4
DOIs
Publication statusPublished - Aug 18 2003

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Keywords

  • Activating receptors
  • Cellular ligands
  • Natural killer cells
  • Protein sequencing
  • Tumors

ASJC Scopus subject areas

  • Immunology

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