Tweet
Sci Adv
. 2025 Aug 22;11(34):eady8610.
doi: 10.1126/sciadv.ady8610. Epub 2025 Aug 22. Characterization of the glycoproteins of fish and amphibian influenza B-like viruses
Gagandeep Singh 1 2 , Jiachen Huang 3 , Disha Bhavsar 1 2 , Kirill Vasilev 1 2 , James A Ferguson 3 , Geert-Jan Boons 4 5 , Viviana Simon 1 2 6 7 8 , Robert P de Vries 4 , Julianna Han 3 , Andrew Ward 3 , Florian Krammer 1 2 6 9
Affiliations
Influenza-like virus sequences previously identified in fish and amphibians cluster as a sister clade of influenza B viruses but remain largely uncharacterized. We demonstrate that salamander influenza-like virus (SILV) hemagglutinin (HA) is functionally divergent from influenza B virus HA and does not bind to α2,3- and α2,6-linked sialic acids. However, the HAs of Siamese algae-eater influenza-like virus (SAEILV) and chum salmon influenza-like virus (CSILV) bind to α2,3-linked sialic acid. Furthermore, SAEILV HA binds to sialyated Lewis X, is activated by human airway enzymes, and is fusogenic over a broad pH range. SAEILV neuraminidase (NA) has a highly conserved active site and a similar structure to other known NAs. We also determined the cryo-electron microscopy structure of the HA of a previously described virus from the same sister clade, the Wuhan spiny eel influenza virus (WSEIV). No cross-reactive antibodies against these HAs or NAs were found in human serum, suggesting that humans are immunologically naïve to these viruses.
. 2025 Aug 22;11(34):eady8610.
doi: 10.1126/sciadv.ady8610. Epub 2025 Aug 22. Characterization of the glycoproteins of fish and amphibian influenza B-like viruses
Gagandeep Singh 1 2 , Jiachen Huang 3 , Disha Bhavsar 1 2 , Kirill Vasilev 1 2 , James A Ferguson 3 , Geert-Jan Boons 4 5 , Viviana Simon 1 2 6 7 8 , Robert P de Vries 4 , Julianna Han 3 , Andrew Ward 3 , Florian Krammer 1 2 6 9
Affiliations
- PMID: 40845102
- DOI: 10.1126/sciadv.ady8610
Influenza-like virus sequences previously identified in fish and amphibians cluster as a sister clade of influenza B viruses but remain largely uncharacterized. We demonstrate that salamander influenza-like virus (SILV) hemagglutinin (HA) is functionally divergent from influenza B virus HA and does not bind to α2,3- and α2,6-linked sialic acids. However, the HAs of Siamese algae-eater influenza-like virus (SAEILV) and chum salmon influenza-like virus (CSILV) bind to α2,3-linked sialic acid. Furthermore, SAEILV HA binds to sialyated Lewis X, is activated by human airway enzymes, and is fusogenic over a broad pH range. SAEILV neuraminidase (NA) has a highly conserved active site and a similar structure to other known NAs. We also determined the cryo-electron microscopy structure of the HA of a previously described virus from the same sister clade, the Wuhan spiny eel influenza virus (WSEIV). No cross-reactive antibodies against these HAs or NAs were found in human serum, suggesting that humans are immunologically naïve to these viruses.