Abstract
Influenza D virus (IDV) utilizes bovines as a primary reservoir with periodical spillover to other hosts. We have previously demonstrated that IDV binds both 9-O-acetylated N-acetylneuraminic acid (Neu5,9Ac2) and 9-O-acetylated N-glycolylneuraminic acid (Neu5Gc9Ac). Bovines produce both Neu5,9Ac2 and Neu5Gc9Ac, while humans are genetically unable to synthesize Neu5Gc9Ac. 9-O-Acetylation of sialic acids is catalyzed by CASD1 via a covalent acetyl-enzyme intermediate. To characterize the role of Neu5,9Ac2 and Neu5Gc9Ac in IDV infection and determine which form of 9-O-acetylated sialic acids drives IDV entry, we took advantage of a CASD1 knockout (KO) MDCK cell line and carried out feeding experiments using synthetic 9-O-acetyl sialic acids in combination with the single-round and multi-round IDV infection assays. The data from our studies show that (i) CASD1 KO cells are resistant to IDV infection and lack of IDV binding to the cell surface is responsible for the failure of IDV replication; (ii) feeding CASD1 KO cells with Neu5,9Ac2 or Neu5Gc9Ac resulted in a dose-dependent rescue of IDV infectivity; and (iii) diverse IDVs replicated robustly in CASD1 KO cells fed with either Neu5,9Ac2 or Neu5Gc9Ac at a level similar to that in wild-type cells with a functional CASD1. These data demonstrate that IDV can utilize Neu5,9Ac2- or non-human Neu5Gc9Ac-containing glycan receptor for infection.
Original language | English |
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Journal | Journal of Virology |
Volume | 98 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2024 |
Bibliographical note
Publisher Copyright:Copyright © 2024 American Society for Microbiology. All Rights Reserved.
Funding
We acknowledge Dr. Ajit Varki (UCSD) and his group for valuable insights regarding the sialic acid feeding experiment. We also thank Dr. Brian Wasik (Cornell University) for his help in data interpretation concerning the CMAH functionality among different animal species. This study was supported by NIH R01AI141889. The authors also thank the support provided by the William Robert Mills Chair Endowment Fund and Agricultural Experiment Station of the University of Kentucky. The members of the Wang-Li lab are particularly appreciated for their great help in the proofreading of the manuscript and suggestions for experiments described in this study. HHS | National Institutes of Health (NIH) R01AI141889 This study was supported by NIH R01AI141889. The authors also thank the support provided by the William Robert Mills Chair Endowment Fund and Agricultural Experiment Station of the University of Kentucky.
Funders | Funder number |
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University of Kentucky | |
National Institutes of Health (NIH) | R01AI141889 |
National Institutes of Health (NIH) |
Keywords
- 9Ac
- CASD1
- Neu5
- Neu5Gc9Ac
- influenza D
- receptor
ASJC Scopus subject areas
- Microbiology
- Immunology
- Insect Science
- Virology