Construction of Recombinant Lactiplantibacillus plantarum NC8 Expressing ETEC FaeC and LngC and Preliminary Evaluation of Immune Responses in an ETEC-Challenged Piglet Model
TL;DR
It is indicated that both recombinant strains induce mucosal and systemic immunity and alleviate ETEC-induced diarrhea, providing a basis for developing oral probiotic vaccines to reduce economic losses in the swine industry.
Abstract
Simple Summary To address ETEC-induced diarrhea and mortality in piglets and the limited protection afforded by commercial vaccines, this study constructed recombinant Lactiplantibacillus plantarum NC8 strains expressing ETEC antigens FaeC and LngC and evaluated their immunoprotective effects. The recombinant strains correctly expressed the target proteins upon lactose induction and exhibited normal growth. After immunization and ETEC challenge, piglets in the recombinant groups showed faster body weight recovery, milder jejunal damage, decreased pro-inflammatory cytokines, increased IL-10 and sIgA levels, and enhanced T/B cell activation in MLNs, LPLs, and spleen. These findings indicate that both recombinant strains induce mucosal and systemic immunity and alleviate ETEC-induced diarrhea, providing a basis for developing oral probiotic vaccines to reduce economic losses in the swine industry.