A short peptidoglycan recognition protein protects Boleophthalmus pectinirostris against bacterial infection via inhibiting bacterial activity

• Published in: Fish & shellfish immunology 2022-08, Vol.127, p.119-128
• Main Authors: Luo, Sheng, Wang, Li-Cong, Shuai, Zhi-Han, Yang, Guan-Jun, Lu, Jian-Fei, Chen, Jiong
• Format: Article
• Language: English
• Subjects: Aeromonas veronii; Antibacterial activity; Boleophthalmus pectinirostris; BpPGRP5
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2022.06.019

Peptidoglycan recognition proteins (PGRPs) belong to a member of pattern-recognition receptors (PRRs), which proposed as antibacterial protein. The present study investigated the antibacterial effect of BpPGRP5 in great blue-spotted mudskipper (Boleophthalmus pectinirostris). BpPGRP5 transcript was detected in all tested tissues with the highest expression level in spleen, and its expression was significantly upregulated in spleen, intestine, and kidney following Aeromonas veronii infection. rBpPGRP5 was found to interact with several polysaccharides and bacteria, including Gram-negative bacteria (Escherichia coli and A. veronii) and Gram-positive bacteria (Listeria monocytogenes and Staphylococcus aureus). rBpPGRP5 inhibited the proliferation of E. coli, S. aureus, L. monocytogenes, and A. veronii in a Zn2+-dependent manner. Furthermore, in vivo studies revealed that intraperitoneal injection of rBpPGRP5 improved the survival rate of A. veronii-infected B. pectinirostris, accompanied by decreased bacterial load in the blood, kidney, intestine, and spleen. Taken together, our results indicated that BpPGRP5 is an antimicrobial protein that protects B. pectinirostris against bacterial infection. •BpPGRP5 transcripts were altered in B.pectinirostris after A.veronii infection.•RBpPGRP5 bound to Lys-PGN, Dap-PGN, LTA, β-Glucan, Mannan, E.coli, A. veronii, L.monocytogenes, and S.aureus.•RBpPGRP5 administration improved the outcomes of A. veronii infected B. pectinirostris.