Identification and Immunological Characterization of α-Enolase from Ctenopharyngodon idellus and the Effects on Intestinal Microflora

Fish is one of the eight most common allergenic foods. Enolase, a prevalent glycolytic enzyme in fish, includes α, β, and γ subtypes. While β-enolase is a known major allergen in aquatic products, the allergenicity of α-enolase remains less studied. Therefore, this study focused on grass carp α-enolase, which was cloned and expressed in prokaryotes. Multiple sequence alignment showed high evolutionary conservation among enolases. Using a BALB/c mouse model, α-enolase did not induce a pronounced allergic response but could elicit Th1 and Th2 immune responses. Furthermore, 16S rDNA sequencing revealed that both α- and β-enolases altered the gut microbiota composition in mice, but β-enolase caused more severe dysbiosis of beneficial intestinal bacteria. These findings provide preliminary research foundations and theoretical evidence for investigating the mechanisms of enolase action in various immune diseases, including food allergies.