The CDE region of feline Calicivirus VP1 protein is a potential candidate subunit vaccine

作者：Lisha Li, Zirui Liu, Jiale Shi, Mengfang Yang, Yuanyuan Yan, Yanan Fu, Zhou Shen, Guiqing Peng · 发表于：BMC Veterinary Research · 年份：2024 · DOI：10.1186/s12917-024-03914-2 · 被引用次数：11 · 研究领域：Viral gastroenteritis research and epidemiology、Respiratory viral infections research、Viral Infections and Immunology Research

BACKGROUND: Feline calicivirus (FCV) infection causes severe upper respiratory disease in cats, but there are no effective vaccines available for preventing FCV infection. Subunit vaccines have the advantages of safety, low cost and excellent immunogenicity, but no FCV subunit vaccine is currently available. The CDE protein is the dominant neutralizing epitope region of the main antigenic structural protein of FCV, VP1. Therefore, this study evaluated the effectiveness of the CDE region as a truncated FCV VP1 protein in preventing FCV infection to provide a strategy for developing potential FCV subunit vaccines. RESULTS: Through the prediction of FCV VP1 epitopes, we found that the E region is the dominant neutralizing epitope region. By analysing the spatial structure of VP1 protein, 13 amino acid sites in the CD and E regions were found to form hydrogen bonding interactions. The results show the presence of these interaction forces supports the E region, helping improve the stability and expression level of the soluble E protein. Therefore, we selected the CDE protein as the immunogen for the immunization of felines. After immunization with the CDE protein, we found significant stimulation of IgG, IgA and neutralizing antibody production in serum and swab samples, and the cytokine TNF-α levels and the numbers of CD4+ T lymphocytes were increased. Moreover, a viral challenge trial indicated that the protection generated by the CDE subunit vaccine significantly reduced the in...