Enhancement of antigen-specific humoral immune responses and protein solubility through conjugation of bacterial flagellin, Vibrio vulnificus FlaB, to the N-terminus of porcine epidemic diarrhea virus surface protein antigen S0

Oh, Seo-ho; Kim Cho, Young-Saeng; Lee, Ho-Bin; Lee, Sang-Mok; Kim, Whee-Soo; Hong, Liang; Cho, Chong-Su; Choi, Yun-Jaie; Kang, Sang-Kee

In our study, we conjugated flagellin from Vibrio vulnificus, FlaB, to the C-or N-terminus of S0 to generate S0-F and F-S0, respectively. We tested the effect of flagellin conjugation to S0 on the enhancement of solubility. To further improve the solubility of each recombinant protein, trigger factor chaperone tig was used, and the solubility of each recombinant protein was assessed in the presence of tig. We also evaluated the ability of the conjugated flagellin to enhance the S0-specific humoral immune response in Balb/c mice and identified different outcomes depending on the direction of fusion. The underlying mechanisms of the consequent results were deduced through in vitro and in vivo experiments. These observations provide crucial information for the development of a novel PED vaccine and flagellin-based immunotherapeutics.