Immunogenicity and protective efficacy of orally administered recombinant Lactobacillus plantarum expressing VP2 protein against IBDV in chicken

I Maqsood; W Shi; L Wang; X Wang; B Han; H Zhao; A M Nadeem; B S Moshin; K Saima; S S Jamal; M F Din; Y Xu; L Tang; Y Li

doi:10.1111/jam.14073

Immunogenicity and protective efficacy of orally administered recombinant Lactobacillus plantarum expressing VP2 protein against IBDV in chicken

J Appl Microbiol. 2018 Aug 17;125(6):1670-1681. doi: 10.1111/jam.14073. Online ahead of print.

Authors

I Maqsood¹, W Shi¹, L Wang¹, X Wang¹, B Han¹, H Zhao¹, A M Nadeem², B S Moshin¹, K Saima², S S Jamal³, M F Din⁴, Y Xu¹, L Tang¹, Y Li¹

Affiliations

¹ College of Veterinary Medicine, Northeast Agricultural University, Harbin, China.
² College of Life Sciences, Anhui Agricultural University, Hefei, China.
³ Department of Management, Harbin Institute of Technology, Harbin, China.
⁴ Department of Molecular Genetics, Chinese Academy of Science (CAS), University of Science and Technology (USTC), Hefei, China.

Abstract

Aim: To develop an effective oral vaccine against the very virulent infectious bursal disease virus (vvIBDV), we generated two recombinant Lactobacillus plantarum strains (pPG612-VP2/LP and pPG612-T7g10-VP2/LP, which carried the T7g10 translational enhancer) that displayed the VP2 protein on the surface, and compared the humoral and cellular immune responses against vvIBDV in chickens.

Methods and results: We genetically engineered the L. plantarum strains pPG612-VP2/LP and pPG612-T7g10-VP2/LP constitutively expressing the VP2 protein of vvIBDV. We found that the T7g10 enhancer efficiently upregulates VP2 expression in pPG612-T7g10-VP2/LP. Orally administered, pPG612-T7g10-VP2/LP exhibited significant levels of protection (87·5%) against vvIBDV in chickens, indicating improved immunogenicity. Chickens in the pPG612-T7g10-VP2/LP group produced higher levels of interferons (IFN-γ) and interleukins (IL-2 and IL-4) than those in the pPG612-VP2/LP group. CD8+ and CD4+ lymphocyte counts indicated greater stimulation in the pPG612-T7g10-VP2/LP group (13·3 and 21·0% respectively) than in the pPG612-VP2/LP group (10·4 and 14·0% respectively). Thus, pPG612-T7g10-VP2/LP could induce strong humoral and cellular immune responses against vvIBDV.

Conclusions: The recombinant L. plantarum that expresses pPG612-T7g10-VP2 is a promising candidate for oral vaccine development against vvIBDV.

Significance and impact of the study: The recombinant Lactobacillus delivery system provides a promising strategy for vaccine development against vvIBDV in chickens.

Keywords: Lactobacillus plantarum; VP2 protein; immune response; immunogenicity; infectious bursal disease virus; recombinant oral vaccine; translational enhancer.

Grants and funding

2015BAD12B01-4/The National Technology and Research Project of China