Targeting Inhibition of SmpB by Peptide Aptamer Attenuates the Virulence to Protect Zebrafish against Aeromonas veronii Infection

• Published in: Frontiers in microbiology Vol. 8; p. 1766
• Main Authors: Liu, Peng, Huang, Dongyi, Hu, Xinwen, Tang, Yanqiong, Ma, Xiang, Yan, Rihui, Han, Qian, Guo, Jianchun, Zhang, Yueling, Sun, Qun, Liu, Zhu
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 13.09.2017
• Subjects: Aeromonas veronii; bacterial two-hybrid system; live attenuated vaccines; Microbiology; selection of peptide aptamers library; SmpB; Aeromonas veronii; selection of peptide aptamers library; SmpB; bacterial two-hybrid system; live attenuated vaccines
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2017.01766

is an important pathogen of aquatic animals, wherein Small protein B (SmpB) is required for pathogenesis by functioning as both a component in stalled-ribosome rescue and a transcription factor in upregulation of virulence gene expression. Here a specific peptide aptamer PA-1 was selected from peptide aptamer library by bacterial two-hybrid system employing pBT-SmpB as bait. The binding affinity between SmpB and PA-1 was evaluated using enzyme-linked immunosorbent assay. The key amino acids of SmpB that interact with PA-1 were identified. After PA-1 was introduced into , the engineered strain designated as (pN-PA-1) was more sensitive and grew slower under salt stress in comparison with wild type, as the disruption of SmpB by PA-1 resulted in significant transcription reductions of virulence-related genes. Consistent with these observations, (pN-PA-1) was severely attenuated in model organism zebrafish, and vaccination of zebrafish with (pN-PA-1) induced a strong antibody response. The vaccinated zebrafish were well protected against subsequent lethal challenges with virulent parental strain. Collectively, we propose that targeting inhibition of SmpB by peptide aptamer PA-1 possesses the desired qualities for a live attenuated vaccine against pathogenic .