An IL-1β homologue induced inflammation and antibacterial immune defense in Siberian sturgeon (Acipenser baeri). Issue 118 (November 2021)

• Record Type: Journal Article
• Authors: Wang, Xiaowen; Zhang, Rong; Liu, Lili; Ma, Guoqing; Zhu, Hua
• Is Part Of: Fish & shellfish immunology. Issue 118(2021)
• Page Start: 283
• Page End: 293
• Publication Date: 2021-11
• Subjects: Acipenser baeri -- Interleukin-1β -- Anti-bacterial ability -- Immunostimulant; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2021.08.030
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Interleukin-1β is a key pro-inflammatory cytokine functioning in initiation of inflammatory responses against bacterial- and viral-infections. In the present study, a putative IL-1β counterpart was identified from Siberian sturgeon ( Acipenser baeri ) and designated as AbIL-1β. The Abil-1β cDNA sequence consists of 1130 bp with an open reading frame (ORF) of 585 bp, which encodes a 194 amino acid (aa) protein. Multiple amino acid sequence alignment revealed that a possible mature peptide could start at Leu 18, although no cut site for ICE (IL-1β converting enzyme) enzyme was present in Siberian sturgeon IL-1β. Even if AbIL-1β shares a relative low identity (33.6%) with another sturgeon type II IL-1β gene from Acipenser dabryanus, they still clustered together in phylogenetic tree. Endogenous Abil-1β was highly expressed in brain, blood, head kidney and spleen of healthy Siberian sturgeon, and remarkably up regulated in head kidney, spleen, and liver upon Aeromonas hydrophila ( A.h ) challenge. Consistently, in vitro stimulation test using heat-killed A.h and LPS significantly increased Abil-1β transcripts of primary spleen cells. To investigate the bactericidal capability of AbIL-1β, recombinant AbIL-1β (rAbIL-1β) was generated by prokaryotes. Pre-injection of rAbIL-1β reduced the bacterial load in sturgeon spleen after A.h infection. Further, rAbIL-1β was served as feed additive and demonstrated to enhance hybrid sturgeon's defense against A.h infection by increased expressional levels of immune-related genes ( IL-1β, IL-6, IL-8, IgM and MHCIIβ ), elevated activities of serum lysosome, ACH50, and MPO, as well as higher percent survival. In summary, the current results suggested that AbIL-1β functions in immune regulation and could improve sturgeon's resistance to bacterial infection. Highlights: A novel sturgeon Interleukin-1β homologue was characterized and prokaryotically expressed from Siberian sturgeon. Abil-1β was highly expressed in brain, blood, head kidney, spleen, and up-regulated by bacteria A. hydrophila infection. Abil-1β in spleen cells responded to in vitro inactivated A.h and LPS stimulants. Intraperitoneal injection of rAbIL-1β reduced the tissue bacterial loads of sturgeon from A.h infection. Dietary rAbIL-1β additive enhanced hybrid sturgeon's defense against A.h infection.