Recombinant Lactobacillus casei Expressing Capsid Protein VP60 can Serve as Vaccine Against Rabbit Hemorrhagic Disease Virus in Rabbits

Wang, Li; Xia, Tian; Guo, Tiantian; Ru, Yi; Jiang, Yanping; Cui, Wen; Zhou, Han; Qiao, Xinyuan; Tang, Lijie; Xu, Yigang; Li, Yijing

The levels of anti-VP60(VP1)-specific IgG in the sera, and those of SigA in the feces, genital tract secretions, and intestinal mucusa, of the rabbits used in this study, were determined via ELISA. Briefly, polystyrene microtiter plates were coated with RHDV and incubated overnight at 4 • C. After washing thrice with PBST (PBS containing 1% Tween-20), the plates were blocked with 5% skimmed milk at 37 • C for 2 h. After washing thrice with PBST, the collected samples, prepared in triplicate, were diluted with PBS (sera diluted at 1:50; supernatants of feces, tears, vagina, and nasal cavity lavage diluted at 1:10), incubated at 37 • C for 1 h. Then, an HRP-conjugated goat anti-rabbit IgG or IgA antibody (Sigma, Ronkonkoma, NY, USA) was added to each well (at 1:2000), and incubated for 1 h at 37 • C. Color was developed using tetramethylbenzidine (TMB) (Sigma, Ronkonkoma, NY, USA) as a substrate, and absorbance was measured at OD 490.