FIGURE 5.

Linked Fc and TPPPS adjuvant enhance the humoral and cell-mediated immune responses. Chickens in the four groups were, respectively, inoculated with ompA subunit vaccine, ompA–Fc subunit vaccine, TPPPS adjuvant ompA–Fc subunit vaccine, and PBS at 0, 7, and 14 dpv. The specific anti-ompA antibody titers (A) were determined by indirect ELISA as previously described, and the concentrations of IL-2 (B) and IL-4 (C) were determined by commercial ELISA kits; the percentages of CD4+ (D) and CD8+ (E) T lymphocytes and LTRs (F) were detected by flow cytometry and MTT assay, respectively. All values represent the means ± SD of three independent experiments.