Adu OF, Sempere Borau M, Früh SP, Karakus U, Weich. Cell binding, uptake, and infection of influenza A virus using recombinant antibody-based receptors. J Virol. 2025 Apr 10:e0227524
Human and avian influenza A viruses bind to sialic acid (Sia) receptors on cells as their primary receptors, and this results in endocytic uptake of the virus. While the role of Sia on glycoproteins and/or glycolipids for virus entry is crucial, the roles of the carrier proteins are still not well understood. Furthermore, it is still unclear how receptor binding leads to infection, including whether the receptor plays a structural or other roles beyond being a simple tether. To enable the investigation of the receptor binding and cell entry processes in a more controlled manner, we have designed a protein receptor for pandemic H1 influenza A viruses. The engineered receptor possesses the binding domains of an anti-HA antibody prepared as a single-chain variable fragment (scFv) fused with the stalk, transmembrane, and cytoplasmic sequences of the feline transferrin receptor type-1 (fTfR). When expressed in cells that lack efficient display of Sia due to a knockout of the Slc35A1 gene, which encodes for the solute carrier family 35 transporter (SLC35A1), the anti-H1 receptor was displayed on the cell surface, bound virus, or hemagglutinin proteins, and the virus was efficiently endocytosed into the cells. Infection occurred at similar levels to those seen after reintroducing Sia expression, and lower affinity receptor mutants displayed enhanced infections. Treatment with clathrin-mediated endocytosis (CME) inhibitors significantly reduced viral entry, indicating that virus rescue by the antibody-based receptor follows a similar internalization route as Sia-expressing cells.IMPORTANCEInfluenza A viruses primarily circulate among avian reservoir hosts but can also jump species, causing outbreaks in mammals, including humans. A key interaction of the viruses is with host cell sialic acids, which vary in chemical form, in their linkages within the oligosaccharide, and in their display on various surface glycoproteins or glycolipids with differing properties. Here, we report a new method for examining the processes of receptor binding and uptake into cells during influenza A virus infection, by use of an engineered HA-binding membrane glycoprotein, where antibody variable domains are used to bind the virus, and the transferrin receptor uptake structures mediate efficient entry. This will allow us to test and manipulate the processes of cell binding, entry, and infection.
See Also:
Latest articles in those days:
- [preprint]The mammalian-adaptive PB2-E627K substitution preserves viral fitness of clade 2.3.4.4b H5N1 HPAIV in birds 9 hours ago
- Mallard super-shedders of avian influenza exhibit distinct cloacal microbial abundance profiles 13 hours ago
- A digitally immune-optimized influenza vaccine broadly neutralizes swine and human H1N1 influenza viruses and protects from heterologous challenge 13 hours ago
- Associations between vaccine misinformation and influenza vaccine uptake: a population-based interrupted time-series study in China 14 hours ago
- Infection and transmission dynamics of bovine and human influenza A H5N1 viruses in mouse and hamster models 15 hours ago
[Go Top] [Close Window]


