title: Glycan receptor binding of the influenza A virus H7N9 hemagglutinin.
abstract: The advent of H7N9 in early 2013 is of concern for a number of reasons, including its capability to infect humans, the lack of clarity in the etiology of infection, and because the human population does not have pre-existing immunity to the H7 subtype. Earlier sequence analyses of H7N9 hemagglutinin (HA) point to amino acid changes that predicted human receptor binding and impinge on the antigenic characteristics of the HA. Here, we report that the H7N9 HA shows limited binding to human receptors; however, should a single amino acid mutation occur, this would result in structural changes within the receptor binding site that allow for extensive binding to human receptors present in the upper respiratory tract. Furthermore, a subset of the H7N9 HA sequences demarcating coevolving amino acids appears to be in the antigenic regions of H7, which, in turn, could impact effectiveness of the current WHO-recommended prepandemic H7 vaccines.
authors.affiliation: Department of Biological Engineering, Koch Institute of Integrative Cancer Research, Infectious Diseases Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Kannan
authors.initials: K
authors.lastname: Tharakaraman
authors.forename: Akila
authors.initials: A
authors.lastname: Jayaraman
authors.forename: Rahul
authors.initials: R
authors.lastname: Raman
authors.forename: Karthik
authors.initials: K
authors.lastname: Viswanathan
authors.forename: Nathan W
authors.initials: NW
authors.lastname: Stebbins
authors.forename: David
authors.initials: D
authors.lastname: Johnson
authors.forename: Zachary
authors.initials: Z
authors.lastname: Shriver
authors.forename: V
authors.initials: V
authors.lastname: Sasisekharan
authors.forename: Ram
authors.initials: R
authors.lastname: Sasisekharan
mesh_terms: D000595:Amino Acid Sequence; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D058507:Host Specificity; D006801:Humans; D009980:Influenza A virus / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000502:physiology*; D007252:Influenza Vaccines / Q000276:immunology; D007251:Influenza, Human / Q000821:virology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D011134:Polysaccharides / Q000378:metabolism; D011991:Receptors, Virus / Q000737:chemistry / Q000378:metabolism*; D014132:Trachea / Q000821:virology
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D011134:Polysaccharides; D011991:Receptors, Virus; C109963:hemagglutinin, avian influenza A virus