Th17 signature dominates in an antigen recall assay. PBMCs were isolated from F4+ ETEC infected animals and stimulated with F4 fimbriae (5 μg/mL) or medium for 48 h. A The mRNA expression profile in PBMCs was analyzed by qPCR. The mRNA expression level was normalized to the reference genes and then to control PBMCs. * indicates significant differences as compared to the control group. B The secretion of IL-17A, IL-22, IFN-γ and IL-10 by PBMCs was determined by ELISA. Data are presented as mean ± SEM (n = 3 per group). NS: non-stimulated, * p < 0.05, ** p < 0.01 and *** p < 0.001.