The avian coronavirus spike protein

Area of Science:

• Veterinary Virology
• Molecular Biology
• Immunology

Background:

• Avian infectious bronchitis virus (IBV), a Gammacoronavirus, causes significant disease in chickens, impacting respiratory, reproductive, and urogenital systems.
• Control of IBV is challenging due to extensive strain diversity, linked to variations in the spike protein's S1 domain, which affects serotype specificity and cross-protection.
• The viral spike protein is crucial for various stages of the IBV life cycle, including cell binding and entry.

Purpose of the Study:

• To review the current literature on avian coronavirus spike proteins, focusing on their role in host and tissue tropism.
• To summarize recent findings on the binding of recombinant soluble spike protein to chicken tissues.
• To elucidate the spike protein's contribution to pathogenesis and its potential as a target for therapeutic and protective strategies.

Main Methods:

• Literature review of avian coronavirus spike protein research.
• Analysis of amino acid variations in the S1 domain of the spike protein.
• Studies using recombinant soluble spike protein to investigate binding to chicken tissues.
• Development of models to study viral binding, cell entry, tropism, and pathogenesis.

Main Results:

• Amino acid variation in the S1 domain of the spike protein is associated with IBV serotype diversity and limited cross-protection.
• The spike protein plays a critical role in viral attachment to host cells and subsequent entry.
• Experimental models have successfully elucidated the spike protein's contribution to in vivo tropism and pathogenesis.
• Recent studies demonstrate the binding of recombinant soluble spike protein to specific chicken tissues.

Conclusions:

• The avian coronavirus spike protein is a major determinant of host and tissue predilection for IBV.
• Understanding spike protein function is essential for developing strategies to combat IBV.
• Further research into the spike protein's role in pathogenesis and immunity could lead to improved vaccines and therapeutics against infectious bronchitis.