title: Inhibition of Human Metapneumovirus Binding to Heparan Sulfate Blocks Infection in Human Lung Cells and Airway Tissues.
abstract: Human metapneumovirus (HMPV), a recently discovered paramyxovirus, infects nearly 100% of the world population and causes severe respiratory disease in infants, the elderly, and immunocompromised patients. We previously showed that HMPV binds heparan sulfate proteoglycans (HSPGs) and that HMPV binding requires only the viral fusion (F) protein. To characterize the features of this interaction critical for HMPV binding and the role of this interaction in infection in relevant models, we utilized sulfated polysaccharides, heparan sulfate mimetics, and occluding compounds. Iota-carrageenan demonstrated potent anti-HMPV activity by inhibiting binding to lung cells mediated by the F protein. Furthermore, analysis of a minilibrary of variably sulfated derivatives of Escherichia coli K5 polysaccharide mimicking the HS structure revealed that the highly O-sulfated K5 polysaccharides inhibited HMPV infection, identifying a potential feature of HS critical for HMPV binding. The peptide dendrimer SB105-A10, which binds HS, reduced binding and infection in an F-dependent manner, suggesting that occlusion of HS at the target cell surface is sufficient to prevent infection. HMPV infection was also inhibited by these compounds during apical infection of polarized airway tissues, suggesting that these interactions take place during HMPV infection in a physiologically relevant model. These results reveal key features of the interaction between HMPV and HS, supporting the hypothesis that apical HS in the airway serves as a binding factor during infection, and HS modulating compounds may serve as a platform for potential antiviral development.
  
  
  
  Human metapneumovirus (HMPV) is a paramyxovirus that causes respiratory disease worldwide. It has been previously shown that HMPV requires binding to heparan sulfate on the surfaces of target cells for attachment and infection. In this study, we characterize the key features of this binding interaction using heparan sulfate mimetics, identify an important sulfate modification, and demonstrate that these interactions occur at the apical surface of polarized airway tissues. These findings provide insights into the initial binding step of HMPV infection that has potential for antiviral development.
authors.affiliation: Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, USA.
authors.forename: Edita M
authors.initials: EM
authors.lastname: Klimyte
authors.affiliation: Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, USA.
authors.forename: Stacy E
authors.initials: SE
authors.lastname: Smith
authors.affiliation: Glycores 2000 S.r.l., Milan, Italy.
authors.forename: Pasqua
authors.initials: P
authors.lastname: Oreste
authors.affiliation: Department of Clinical and Biological Sciences, University of Turin, S. Luigi Gonzaga Hospital, Orbassano, Turin, Italy.
authors.forename: David
authors.initials: D
authors.lastname: Lembo
authors.affiliation: Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, USA rdutc2@uky.edu.
authors.forename: Rebecca Ellis
authors.initials: RE
authors.lastname: Dutch
mesh_terms: D000072283:A549 Cells; D000998:Antiviral Agents / Q000494:pharmacology*; D016667:Bacterial Capsules / Q000378:metabolism; D002460:Cell Line; D045744:Cell Line, Tumor; D050091:Dendrimers / Q000378:metabolism / Q000494:pharmacology; D004926:Escherichia coli / Q000378:metabolism; D019812:Heparan Sulfate Proteoglycans / Q000378:metabolism; D006497:Heparan Sulfate / Q000378:metabolism*; D006801:Humans; D029121:Metapneumovirus / Q000187:drug effects*; D018184:Paramyxoviridae Infections / Q000188:drug therapy*; D010455:Peptides / Q000494:pharmacology; D012137:Respiratory System / Q000378:metabolism* / Q000821:virology*; D014760:Viral Fusion Proteins / Q000378:metabolism
chemical_list: D000998:Antiviral Agents; D050091:Dendrimers; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D010455:Peptides; D014760:Viral Fusion Proteins; C000590113:SB105-A10; C050673:capsular polysaccharide K5