Surface Display of porcine circovirus type 2 antigen protein cap on the spores of bacillus subtilis 168: An effective mucosal vaccine candidate

Abstract

The oral mucosal vaccine has great potential in preventing a series of diseases caused by porcine circovirus type 2 (PCV2) infection. This study constructed a recombinant Bacillus subtilis RB with PCV2 Capsid protein (Cap) on its spore surface and cotB as a fusion partner. The immune properties of the recombinant strain were evaluated in a mouse model. IgA in intestinal contents and IgG in serum were detected by enzyme-linked immunosorbent assay (ELISA). The results demonstrated that recombinant spores could activate strong specific mucosal and humoral immune responses. In addition, spores showed good mucosal immune adjuvant function, promoting the proliferation of CD3+, CD4+ and CD8+ T cells and other immune cells. We also found that the relative expression of inflammatory cytokines such as IL-1b, IL-6, IL-10, TNF-a and IFN in the small intestinal mucosa was significantly up-regulated under the stimulation of recombinant bacteriophage. These effects are important for the balance of Th1/Th2-like responses. In summary, our results suggest that recombinant B. subtilis RB as a feed additive provides a new strategy for the development of novel and safe PCV2 mucosal subunit vaccines.

Evaluation of the Immunity Responses in Mice to Recombinant Bacillus subtilis Displaying Newcastle Disease Virus HN Protein Truncations

“…Recombinant probiotics displaying the HN protein can elicit specific immune responses when used as mucosal vaccines, offering substantial potential in research and application areas. Our laboratory has successfully constructed several recombinant B. subtilis strains that display heterologous proteins, including Salmonella OmpC [ 52 ], Rotavirus VP8 [ 33 ], and Porcine circovirus type 2 Cap proteins [ 53 ]. In the current study, we excised a portion of the antigenic region from the HN protein and spliced it into smaller fragments following Chen’s methodology [ 32 ].…”

Bacillus subtilis vector based oral rabies vaccines induced potent immune response and protective efficacy in mice

“…So, B. subtilis was selected as the oral vaccine delivery carrier in this study. B. subtilis has strong stress resistance, can resist the erosion of gastric acid in the gastrointestinal tract, and can effectively survive in the low-acid environment in the stomach and complex intestinal conditions ( Zhou et al, 2008a , b ; Li et al, 2022 ). B. subtilis exerts immune adjuvant activity and is effective against most oral antigens ( Tanasienko et al, 2005 ).…”

A Trim-RBD-GEM vaccine candidate protects mice from SARS-CoV-2

“…The GEM-PA surface display system has been applied to animal models, and the results show that it can block viruses, bacteria, parasites, etc. ( Heine et al, 2015 ; Li et al, 2016 , 2022 ; Nganou-Makamdop et al, 2012 ; Rigter et al, 2013 ). Non-transgenic, non-living GEM has little recombinant DNA, reducing the risk of transmission to the environment ( Li et al, 2019 ).…”