OmpW expressed by recombinant Lactobacillus casei elicits protective immunity against Aeromonas veronii in common carp. (August 2019)

• Record Type: Journal Article
• Authors: Zhang, Lei; Li, Zhenxing; Li, Ying; Tian, Jiaxin; Jia, Kaixiang; Zhang, Dongxing; Song, Mingfang; Abbas Raza, Sayed Haidar; Garcia, Matthew; Kang, Yuanhuan; Zheng, Wei; Qian, Aidong; Shan, Xiaofeng; Xu, Yang
• Is Part Of: Microbial pathogenesis. Volume 133(2019)
• Publication Date: 2019-08
• Subjects: Aeromonas veronii -- OmpW -- Lactobacillus casei -- Immune protection; Pathogenic microorganisms -- Periodicals; Pathology, Molecular -- Periodicals; Communicable Diseases -- microbiology -- Periodicals; Communicable Diseases -- parasitology -- Periodicals; Micro-organismes pathogènes -- Périodiques; Pathologie moléculaire -- Périodiques; Electronic journals; 616.9041
• DOI: 10.1016/j.micpath.2019.103552
• Languages: English
• ISSNs: 0882-4010

Abstract

Abstract: Aeromonas veronii is an opportunistic pathogen that is capable of infecting both aquatic livestock and mammals. Natural infection in fishes results in irreparable damage to the aquaculture industry. In this study, we sought to investigate whether recombinant Lactobacillus casei expressing the outer membrane protein W (OmpW) of A.veronii could elicit protective immunity against A.veronii infections. We generated two recombinant Lactobacillus casei (L.casei) strains expressing the OmpW of A.veronii (surface-displayed or secreted) and evaluated the effect on immune responses in a fish model. A 600-bp gene fragment was subcloned into the L.casei expression plasmids pPG-1 (surface-displayed) and pPG-2 (secreted). Expression of the recombinant OmpW protein was also confirmed by Western blot and immunofluorescence assays. Common carp immunized with Lc-pPG-1- OmpW and Lc-pPG-2- OmpW via oral administration elicited high serum specific antibody titers and high LZM, ACP, and SOD activities. High levels of the IL-10, IL-β, IFN-γ, and TNF-α genes in different organs indicated that the inflammatory response and cell immune response were triggered. Additionally, when immunized fish were challenged with A.veronii, Lc-pPG1-OmpW and Lc-pPG2-OmpW demonstrated 40% and 50% protective efficacy. These data indicate that the combination of OmpW delivery and the lactic acid bacteria (LAB) approach may be a promising mucosal therapeutic strategy for treatment of A.veronii . Highlights: Two recombinant Lactobacillus casei expressing the OmpW of A.veronii were developed and evaluated in carps. The vaccines elicited strong inflammatory response and cell immune response. The vaccines demonstrated 40% and 50% protective efficacy against A.veronii.