Figure 7
Proliferative responses of PBMCs from chickens immunized with UV-inactivated EB in combination with different doses of VCG. Groups of chickens (8/group) were immunized IN with two doses of the vaccine formulations and controls, 2 weeks apart. Three weeks after the booster immunization, PBMCs obtained by Lymphoprep density gradient centrifugation were restimulated in vitro with 106 IFU of UV-irradiated C. psittaci EBs (C. psittaci antigen) for 24 h at 37℃ in 5% CO2. The antigen-specific proliferative response of PBMCs was determined using **the 5-Bromo-2’-deoxy-uridine (BrdU) cell proliferation assay kit (#K306; Abcam, Beijing, China); incorporation was detected by addition of TMB substrate and the optical density was read at 450 nm. Results are expressed as the stimulation index (SI), the ratio between absorbance values of stimulated and non-stimulated cells and the bars represent the mean and SD of three independent experiments. Significant differences between groups were evaluated by One-way ANOVA with Tukey’s post multiple comparison test at p*** < 0.001 and p** < 0.01. Abbreviations: − ve ctr negative controls; + ve ctr positive control.
