scholarly journals Breaking the Convention: Sialoglycan Variants, Coreceptors, and Alternative Receptors for Influenza A Virus Entry

2019 ◽  
Vol 94 (4) ◽  
Author(s):  
Umut Karakus ◽  
Marie O. Pohl ◽  
Silke Stertz

ABSTRACT The influenza A virus (IAV) envelope protein hemagglutinin binds α2,6- or α2,3-linked sialic acid as a host cell receptor. Bat IAV subtypes H17N10 and H18N11 form an exception to this rule and do not bind sialic acid but enter cells via major histocompatibility complex (MHC) class II. Here, we review current knowledge on IAV receptors with a focus on sialoglycan variants, protein coreceptors, and alternative receptors that impact IAV attachment and internalization beyond the well-described sialic acid binding.

1992 ◽  
Vol 51 (3) ◽  
pp. 230-236 ◽  
Author(s):  
Kevan L. Hartshorn ◽  
David E. Daigneault ◽  
Mitchell R. White ◽  
Alfred I. Tauber

2019 ◽  
Vol 15 (6) ◽  
pp. e1007860 ◽  
Author(s):  
Wenjuan Du ◽  
Hongbo Guo ◽  
Vera S. Nijman ◽  
Jennifer Doedt ◽  
Erhard van der Vries ◽  
...  

2017 ◽  
Vol 91 (9) ◽  
Author(s):  
Meiling Dai ◽  
Ryan McBride ◽  
Jos C. F. M. Dortmans ◽  
Wenjie Peng ◽  
Mark J. G. Bakkers ◽  
...  

ABSTRACT The emergence of the novel influenza A virus (IAV) H7N9 since 2013 has caused concerns about the ability of the virus to spread between humans. Analysis of the receptor-binding properties of the H7 protein of a human isolate revealed modestly increased binding to α2,6 sialosides and reduced, but still dominant, binding to α2,3-linked sialic acids (SIAs) compared to a closely related avian H7N9 virus from 2008. Here, we show that the corresponding N9 neuraminidases (NAs) display equal enzymatic activities on a soluble monovalent substrate and similar substrate specificities on a glycan array. In contrast, solid-phase activity and binding assays demonstrated reduced specific activity and decreased binding of the novel N9 protein. Mutational analysis showed that these differences resulted from substitution T401A in the 2nd SIA-binding site, indicating that substrate binding via this site enhances NA catalytic activity. Substitution T401A in the novel N9 protein appears to functionally mimic the substitutions that are found in the 2nd SIA-binding site of NA proteins of avian-derived IAVs that became human pandemic viruses. Our phylogenetic analyses show that substitution T401A occurred prior to substitutions in hemagglutinin (HA), causing the altered receptor-binding properties mentioned above. Hence, in contrast to the widespread assumption that such changes in NA are obtained only after acquisition of functional changes in HA, our data indicate that mutations in the 2nd SIA-binding site may have enabled and even driven the acquisition of altered HA receptor-binding properties and may have contributed to the spread of the novel H7N9 viruses. IMPORTANCE Novel H7N9 IAVs continue to cause human infections and pose an ongoing public health threat. Here, we show that their N9 proteins display reduced binding to and lower enzymatic activity against multivalent substrates, resulting from mutation of the 2nd sialic acid-binding site. This mutation preceded and may have driven the selection of substitutions in H7 that modify H7 receptor-binding properties. Of note, all animal IAVs that managed to cross the host species barrier and became human viruses carry mutated 2nd sialic acid-binding sites. Screening of animal IAVs to monitor their potential to cross the host species barrier should therefore focus not only on the HA protein, but also on the functional properties of NA.


2021 ◽  
Vol 478 (2) ◽  
pp. 423-441
Author(s):  
Stefano Elli ◽  
Nicola Gambacorta ◽  
Timothy R. Rudd ◽  
Mikhail Matrosovich ◽  
Marco Guerrini

The neuraminidases (NAs) of avian influenza viruses (IAVs) contain a second sialic acid-binding site (2SBS), historically known as the hemadsorption site, which is separated from the sialyl-hydrolase catalytic site and serves to facilitate NA catalytic activity towards multivalent sialyl-capped glycoconjugates. Transmission and adaptation of avian IAVs to humans decreases hemadsorption and catalytic activities of the NA. Here, we report the molecular recognition features of the NA 2SBS of two pandemic H1N1 IAVs, A/Brevig Mission /1/1918 (BM18) and A/California/04/2009 (CA09), differing by their 2SBS activity. Using explicit solvent MD simulation, molecular mechanics, and glycosidic conformation analysis we initially analyzed the interactions of BM18 2SBS with two sialyllacto-N-tetraose pentasaccharides, 3′SLN-LC and 6′SLN-LC, which are models for the glycan receptors of IAVs in birds and humans, respectively. These studies characterize the binding specificity of BM18 2SBS towards human-type and avian-type receptors and identifies the key amino acids that affects binding. We next compared the interactions of the 2SBSs of BM18 and CA09 with 6′SLN-LC, revealing the critical effect of amino acid 372 on binding. Our results expand the current knowledge of the molecular features of NA 2SBSs and its alteration during the adaptation of avian IAVs to humans.


2020 ◽  
Vol 16 (8) ◽  
pp. e1008816 ◽  
Author(s):  
Wenjuan Du ◽  
Margreet A. Wolfert ◽  
Ben Peeters ◽  
Frank J. M. van Kuppeveld ◽  
Geert-Jan Boons ◽  
...  

FEBS Journal ◽  
2020 ◽  
Author(s):  
Wenjuan Du ◽  
Erik de Vries ◽  
Frank J. M. van Kuppeveld ◽  
Mikhail Matrosovich ◽  
Cornelis A. M. de Haan

2012 ◽  
Vol 86 (19) ◽  
pp. 10704-10713 ◽  
Author(s):  
H. S. Y. Leung ◽  
O. T. W. Li ◽  
R. W. Y. Chan ◽  
M. C. W. Chan ◽  
J. M. Nicholls ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu-Jen Chang ◽  
Cheng-Yun Yeh ◽  
Ju-Chien Cheng ◽  
Yu-Qi Huang ◽  
Kai-Cheng Hsu ◽  
...  

AbstractEradicating influenza A virus (IAV) is difficult, due to its genetic drift and reassortment ability. As the infectious cycle is initiated by the influenza glycoprotein, hemagglutinin (HA), which mediates the binding of virions to terminal sialic acids moieties, HA is a tempting target of anti-influenza inhibitors. However, the complexity of the HA structure has prevented delineation of the structural characterization of the HA protein–ligand complex. Our computational strategy efficiently analyzed > 200,000 records of compounds held in the United States National Cancer Institute (NCI) database and identified potential HA inhibitors, by modeling the sialic acid (SA) receptor binding site (RBS) for the HA structure. Our modeling revealed that compound NSC85561 showed significant antiviral activity against the IAV H1N1 strain with EC50 values ranging from 2.31 to 2.53 µM and negligible cytotoxicity (CC50 > 700 µM). Using the NSC85561 compound as the template to generate 12 derivatives, robust bioassay results revealed the strongest antiviral efficacies with NSC47715 and NSC7223. Virtual screening clearly identified three SA receptor binding site inhibitors that were successfully validated in experimental data. Thus, our computational strategy has identified SA receptor binding site inhibitors against HA that show IAV-associated antiviral activity.


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