AUTHOR=Xue Ying , Zhang Bo , Wang Nan , Huang Hai-Bin , Quan Yu , Lu Hui-Nan , Zhu Zhi-Yu , Li Jun-Yi , Pan Tian-Xu , Tang Yue , Jiang Yan-Long , Shi Chun-Wei , Yang Gui-Lian , Wang Chun-Feng 

TITLE=Oral Vaccination of Mice With Trichinella spiralis Putative Serine Protease and Murine Interleukin-4 DNA Delivered by Invasive Lactiplantibacillus plantarum Elicits Protective Immunity

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.859243

DOI=10.3389/fmicb.2022.859243

ISSN=1664-302X

ABSTRACT=<p>Trichinellosis is a serious zoonotic parasitic disease caused by <italic>Trichinella spiralis</italic> (<italic>T. spiralis</italic>) that causes considerable economic losses for the global pig breeding and food industries. As such, there is an urgent need for a vaccine that can prevent <italic>T. spiralis</italic> infection. Previous studies have reported that recombinant invasive <italic>Lactococcus lactis</italic> (LL) expressing <italic>Staphylococcus aureus</italic> fibronectin binding protein A (LL-FnBPA+) can transfer DNA vaccines directly to dendritic cells (DCs) across an epithelial cell monolayer, leading to significantly higher amounts of heterologous protein expression compared to non-invasive <italic>Lactococcus lactis</italic>. In this study, the invasive bacterium <italic>Lactiplantibacillus plantarum</italic> (<italic>L. plantarum</italic>) expressing FnBPA was used as a carrier to deliver a novel oral DNA vaccine consisting of <italic>T. spiralis</italic> adult putative serine protease (Ts-ADpsp) and murine interleukin (IL)-4 DNA to mouse intestinal epithelial cells. Experimental mice were orally immunized 3 times at 10-day intervals. At 10 days after the last vaccination, mice were challenged with 350 <italic>T. spiralis</italic> infective larvae by oral inoculation. Immunization with invasive <italic>L. plantarum</italic> harboring pValac-Ts-ADpsp/pSIP409-FnBPA induced the production of anti-Ts-ADpsp-specific IgG of serum, type 1 and 2 helper T cell cytokines of mesenteric lymph node (MLN) and spleen, secreted (s) IgA of intestinal lavage, and decreased <italic>T. spiralis</italic> burden and intestinal damage compared to immunization with non-invasive <italic>L. plantarum</italic> expressing Ts-ADpsp (pValac-Ts-ADpsp/pSIP409). Thus, invasive <italic>L. plantarum</italic> expressing FnBPA and IL-4 stimulates both mucosal and cellular immune response to protect against <italic>T. spiralis</italic> infection, highlighting its therapeutic potential as an effective DNA vaccine for trichinellosis.</p>