AUTHOR=Zhang Xiaoyu , Xiao Huijie , Zhang Huaiyu , Jiang Yang 

TITLE=Lactobacillus plantarum surface-displayed FomA (Fusobacterium nucleatum) protein generally stimulates protective immune responses in mice

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1228857

DOI=10.3389/fmicb.2023.1228857

ISSN=1664-302X

ABSTRACT=<p>A significant correlation is observed between <italic>Fusobacterium nucleatum</italic> (<italic>F. nucleatum</italic>) and the evolution of inflammatory bowel disease (IBD). Particularly, FomA, a critical pathogenic element of <italic>F. nucleatum</italic>, inflicts substantial detriment to human intestinal health. Our research focused on the development of recombinant <italic>Lactobacillus plantarum</italic> that expresses FomA protein, demonstrating its potential in protecting mice from severe IBD induced by <italic>F</italic>. <italic>nucleatum</italic>. To commence, two recombinant strains, namely <italic>L. plantarum</italic> NC8-pSIP409-pgsA'-FomA and NC8-pSIP409-FnBPA-pgsA'-FomA, were successfully developed. Validation of the results was achieved through flow cytometry, ELISA, and MTT assays. It was observed that recombinant <italic>L. plantarum</italic> instigated mouse-specific humoral immunity and elicited mucosal and T cell-mediated immune responses. Significantly, it amplified the immune reaction of B cells and CD4<sup>+</sup>T cells, facilitated the secretion of cytokines such as IgA, IL4, and IL10, and induced lymphocyte proliferation in response to FomA protein stimulation. Finally, we discovered that administering recombinant <italic>L. plantarum</italic> could protect mice from severe IBD triggered by <italic>F. nucleatum</italic>, subsequently reducing pathological alterations and inflammatory responses. These empirical findings further the study of an innovative oral recombinant <italic>Lactobacillus</italic> vaccine.</p>