Α-Enolase as a novel vaccine candidate against Streptococcus dysgalactiae infection in cobia (Rachycentron canadum L.). Issue 98 (March 2020)

• Record Type: Journal Article
• Authors: Thu Nguyen, Thuy Thi; Nguyen, Hai Trong; Wang, Yi-Ting; Wang, Pei-Chi; Chen, Shih-Chu
• Is Part Of: Fish & shellfish immunology. Issue 98(2020)
• Page Start: 899
• Page End: 907
• Publication Date: 2020-03
• Subjects: α-Enolase -- Streptococcus dysgalactiae -- Cobia -- ISA 763 AVG -- Subunit vaccine; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2019.11.050
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Streptococcus dysgalactiae is an important pathogenic bacterium that has caused economic loss for the cobia industry in Taiwan, ROC. This study presents a highly effective subunit vaccine composed of a moonlight protein, α-enolase, for the prevention of S. dysgalactiae infection. First, α-enolase was cloned, transformed, and expressed in E. coli for production of recombinant protein. Then, the protective efficacies of α-enolase recombinant protein were evaluated in combination with either a pro-inflammatory cytokine, TNF-α, or an oil adjuvant, ISA 763 AVG. The results showed that the combination of α-enolase and ISA 763 AVG was highly protective (RPS = 88.89%), while a negative effect was found in the group immunised with α-enolase adjuvanted with TNF-α (RPS = 22.22%). A further study was conducted with double dose of ISA 763 AVG, which led to an increased RPS value of 97.37%. Moreover, immunised cobia exhibited significantly greater lysozyme activity, antibody responses, and expression of certain immune-related genes post-challenge. Altogether, our results demonstrated that a combination of α-enolase recombinant protein with ISA 763 AVG adjuvant is a promising vaccine that can be employed for protection of cobia against S. dysgalactiae infection. Highlights: Recombinant α-enolase (rEnolase) derived from Streptococcus dysgalactiae was produced in Escherichia coli and formulated with ISA763 AVG adjuvant or cobia TNF-α. Vaccination of cobia with rEnolase and ISA763 AVG significantly induced greater serum antibody response, lysozyme activity and immune-related genes expression. Vaccinated fish was highly protected from a virulent Streptococcus dysgalactiae challenge with the relative percent survival of 97.37%.