NKp46 O-glycan sequences that are involved in the interaction with hemagglutinin type 1 of influenza virus.
Natural killer (NK) cells serve as a crucial first-line defense against tumors and virus-infected cells. We previously showed that lysis of influenza virus (IV)-infected cells is mediated by the interaction between the NK receptor, NKp46, and the IV hemagglutinin (HA) type 1 expressed by the infected cells. This interaction requires the presence of sialyl groups on the NKp46-T225 O-glycoforms. In the current study, we analyzed the O-glycan sequences that are imperative for the interaction between recombinant NKp46 (rNKp46) and IV H1N1 strains. We first showed that rNKp46 binding to IV H1N1 is not mediated by a glycoform unique to the Thr225 site. We then characterized the O-glycan sequences that mediate the interaction of rNKp46 and IV H1N1; we employed rNKp46s with dissimilar glycosylation patterns and IV H1N1 strains with different sialic acid alpha2,3 and alpha2,6 linkage preferences. The branched alpha2,3-sialylated O-glycoform Neu5NAcalpha2,3-Galbeta1,4-GlcNAcbeta1,6[Neu5NAcalpha2,3-Galbeta1,3]GalNAc competently mediated the interaction of rNKp46 with IV H1N1, manifesting a preference for alpha2,3 linkage. In contrast, the linear alpha2,3-sialylated O-glycoform Neu5NAcalpha2,3-Galbeta1,3-GalNAc was not correlated with enhanced interaction between rNKp46 and IV H1N1 or a preference for alpha2,3 linkage. The branched alpha2,3- and alpha2,6-sialylated O-glycoform Neu5NAcalpha2,3-Galbeta1,3[Neu5NAcalpha2,6]GalNAc competently mediated the interaction of rNKp46 with IV H1N1, manifesting a preference for alpha2,6 linkage. Previous viral HA-binding-specificity studies were performed with glycopolymer conjugates, free synthetic sialyl oligosaccharides, and sialidase-treated cells. This study shed light on the O-glycan sequences involved in the interaction of glycoprotein and viral hemagglutinins and may help in the design of agents inhibitory to hemagglutinin for influenza treatment.
Department of Microbiology and Immunology and the National Institute for Biotechnology in the Negev, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
Michal
M
Mendelson
Yoram
Y
Tekoah
Alon
A
Zilka
Orly
O
Gershoni-Yahalom
Roi
R
Gazit
Hagit
H
Achdout
Nicolai V
NV
Bovin
Tal
T
Meningher
Michal
M
Mandelboim
Ofer
O
Mandelboim
Ayelet
A
David
Angel
A
Porgador
D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000378:metabolism*; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D055627:Natural Cytotoxicity Triggering Receptor 1 / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs
D019267:Hemagglutinin Glycoproteins, Influenza Virus; C112260:NCR1 protein, human; D055627:Natural Cytotoxicity Triggering Receptor 1; D011134:Polysaccharides; C483468:hemagglutinin, human influenza A virus