Fig. 2. Cytokine responses following vaccination with the individual vaccine strain or a cocktail of all 4 vaccine strains. Splenocytes (1 × 106/mL, n = 5) isolated from BALB/c mice at day 14 post-vaccination were stimulated with their respective vaccine antigen for 24 h, and subsequently analyzed for induction of IL-4 and IFN-γ mRNA transcription levels by quantitative real time polymerase chain reaction assay. (A) IL-4 and IFN-γ induction levels in splenocytes of mice vaccinated by the individual vaccine strains. (B) IL-4 and IFN-γ induction levels in splenocytes of mice vaccinated with a cocktail of all 4 strains. Results are expressed as relative fold change in mRNA transcription levels of stimulated splenocytes from vaccinated mice compared to the Salmonella vector control group. Gene expressions are normalized to glyceraldehyde 3-phosphate dehydrogenase, and mRNA levels of naive stimulated cells are used as the calibrator.
Data presented are mean ± standard deviation of 5 mice per group. The significance of the data was examined using 1-way analysis of variance with Tukey's multiple comparison test.
mRNA, messenger RNA; NS, not significant; IL, interleukin; IFN, interferon; LfliC, Lawsonia flagellin; Lhly, Lawsonia hemolysin.
*p < 0.05.