Alterations in receptor binding properties of recent human influenza H3N2 viruses are associated with reduced natural killer cell lysis of infected cells.
Natural killer (NK) cell recognition of influenza virus-infected cells involves hemagglutinin (HA) binding to sialic acid (SA) on activating NK receptors. SA also acts as a receptor for the binding of influenza virus to its target host cells. The SA binding properties of H3N2 influenza viruses have been observed to change during circulation in humans: recent isolates are unable to agglutinate chicken red blood cells and show reduced affinity for synthetic glycopolymers representing SA-alpha-2,3-lactose (3'SL-PAA) and SA-alpha-2,6-N-acetyl lactosamine (6'SLN-PAA) carbohydrates. Here, NK lysis of cells infected with human H3N2 influenza viruses isolated between 1969 and 2003 was analyzed. Cells infected with recent isolates (1999 to 2003) were found to be lysed less effectively than cells infected with older isolates (1969 to 1996). This change occurred concurrently with the acquisition of two new potential glycosylation site motifs in HA. Deletion of the potential glycosylation site motif at 133 to 135 in HA1 from a recent isolate partially restored the agglutination phenotype to a recombinant virus, indicating that the HA-SA interaction is inhibited by the glycosylation modification. Deletion of either of the recently acquired potential glycosylation sites from HA led to increased NK lysis of cells infected with recombinant viruses carrying modified HA. These results indicate that alterations in HA glycosylation may affect NK cell recognition of influenza virus-infected cells in addition to virus binding to host cells.
Imperial College London, Department of Virology, Division of Investigative Science, Faculty of Medicine, St. Mary's Campus, Norfolk Place, London W2 1PG, United Kingdom. w.barclay@imperial.ac.uk.
Rachel E
RE
Owen
Eriko
E
Yamada
Catherine I
CI
Thompson
Louisa J
LJ
Phillipson
Clare
C
Thompson
Elizabeth
E
Taylor
Maria
M
Zambon
Helen M I
HM
Osborn
Wendy S
WS
Barclay
Persephone
P
Borrow
D001665:Binding Sites; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic; D006031:Glycosylation; D006388:Hemagglutinins; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000502:physiology*; D007251:Influenza, Human / Q000821:virology*; D007694:Killer Cells, Natural / Q000276:immunology*; D011991:Receptors, Virus / Q000737:chemistry*; D053585:Virus Attachment
D006388:Hemagglutinins; D011991:Receptors, Virus