TY - JOUR
T1 - Identification of PVR (CD155) and Nectin-2 (CD112) as cell surface ligands for the human DNAM-1 (CD226) activating molecule
AU - Bottino, Cristina
AU - Castriconi, Roberta
AU - Pende, Daniela
AU - Rivera, Paola
AU - Nanni, Marina
AU - Carnemolla, Barbara
AU - Cantoni, Claudia
AU - Grassi, Jessica
AU - Marcenaro, Stefania
AU - Reymond, Nicolas
AU - Vitale, Massimo
AU - Moretta, Lorenzo
AU - Lopez, Marc
AU - Moretta, Alessandro
PY - 2003/8/18
Y1 - 2003/8/18
N2 - 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).
AB - 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).
KW - Activating receptors
KW - Cellular ligands
KW - Natural killer cells
KW - Protein sequencing
KW - Tumors
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U2 - 10.1084/jem.20030788
DO - 10.1084/jem.20030788
M3 - Article
C2 - 12913096
AN - SCOPUS:0042922822
VL - 198
SP - 557
EP - 567
JO - Journal of Experimental Medicine
JF - Journal of Experimental Medicine
SN - 0022-1007
IS - 4
ER -