Figure 6.

OMPs-specific cell-mediated immune response in OMPs-F-PNPs orally inoculated and Salmonella-challenged chickens.

Notes: (A) Flow cytometry analyses of CD8⁺/CD4⁺ cell ratio. Splenocytes were immunostained with fluorochrome-labeled mouse anti-chicken CD4 and mouse anti-chicken CD8α antibody. The frequency of CD4⁺ and CD8⁺ lymphocytes in the spleen was examined, and the result was expressed as CD8⁺/CD4⁺ cell ratio. (B) Serum IFN-γ levels estimated by ELISA. (C) OMPs-specific lymphocytes’ proliferation was measured as stimulation index values in PBMCs by using a calorimetric assay. Each bar is the mean ± SEM of 8–10 chickens, and the data were analyzed by nonparametric Kruskal–Wallis test followed by P-value differences in between the groups determined by Mann–Whitney test. Asterisk refers to statistical difference between two indicated groups (^*P<0.05). OMPs-F-PNPs, OMPs and F-protein-entrapped and surface F-protein-coated PNPs.

Abbreviations: Ch, challenge; F, flagellar; OMPs, outer membrane proteins; IFN-γ, interferon gamma; PBMCs, peripheral blood mononuclear cells; PNPs, polyanhydride nanoparticles; SEM, standard error of the mean.