Functional study of a role of N-terminal HA stem region of swine influenza A virus in virus replication

Zhao Wang, Jieshi Yu, Zizhang Sheng, Ben M. Hause, Feng Li, Radhey S. Kaushik, Dan Wang

Research output: Contribution to journalArticlepeer-review


Swine influenza A virus (SIV) is both a pathogen of economic significance to the swine industry and a potential zoonotic organism that may be transmitted to humans. We described here the detailed characterization of a role of N-terminal B-loop and CD helix of HA2 in swine influenza A virus replication. Results of our experiments demonstrated that Hemagglutinin (HA) protein of swine influenza virus could tolerate some mutations in functionally conserved B-loop and CD helix. These mutations, however, have substantially attenuated influenza virus replication in both cell lines and porcine primary tracheal epithelial cells. Significantly, we found that some B-loop or CD helix mutations generated virus mutants that replicated in MDCK and ST cell lines but failed to replicate in primary tracheal epithelial cells, thereby suggesting that swine HA protein may function as a viral virulence and pathogenesis factor. The described mutations may be further explored as attenuated vaccine candidates that can effectively prevent or eliminate the spread of influenza virus within and between swine herds.

Original languageEnglish
Article number109132
JournalVeterinary Microbiology
StatePublished - Jul 2021

Bibliographical note

Funding Information:
We thank our lab members for carefully proof-reading the manuscript. The work was in part supported by SDSU Agricultural Experiment Station (F. Li and R. Kaushik).

Publisher Copyright:
© 2021


  • B loop
  • CD helix
  • Hemagglutinin
  • Swine influenza A virus
  • Virus replication

ASJC Scopus subject areas

  • Microbiology
  • Veterinary (all)


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