Beijing Fisheries Research Institute & Beijing Key Laboratory of Fishery Biotechnology, Beijing, 100068, People's Republic of China; National Freshwater Fisheries Engineering Technology Research Center, Beijing, 100068, People's Republic of China.
Beijing Fisheries Research Institute & Beijing Key Laboratory of Fishery Biotechnology, Beijing, 100068, People's Republic of China; National Freshwater Fisheries Engineering Technology Research Center, Beijing, 100068, People's Republic of China.
Fish Shellfish Immunol. 2021 Nov;118:283-293. doi: 10.1016/j.fsi.2021.08.030. Epub 2021 Sep 16.
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, 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.
白细胞介素-1β 是一种关键的促炎细胞因子，可在启动针对细菌和病毒感染的炎症反应中发挥作用。在本研究中，从西伯利亚鲟（Acipenser baeri）中鉴定出一种假定的白细胞介素-1β 对应物，并将其命名为 AbIL-1β。Abil-1β cDNA 序列长 1130bp，开放阅读框（ORF）为 585bp，编码 194 个氨基酸（aa）的蛋白质。多个氨基酸序列比对表明，一个可能的成熟肽可能从亮氨酸开始，尽管西伯利亚鲟白细胞介素-1β中没有 ICE（白细胞介素-1β 转化酶）酶的切割位点。即使 AbIL-1β 与另一种来自达氏鲟的 II 型鲟鱼白细胞介素-1β基因的同源性相对较低（33.6%），它们在系统发育树中仍然聚类在一起。内源性 Abil-1β在健康西伯利亚鲟的大脑、血液、头肾和脾脏中高度表达，在受到嗜水气单胞菌（A.h）挑战后，头肾、脾脏和肝脏中的表达显著上调。一致地，使用热灭活的 A.h 和 LPS 进行体外刺激试验显著增加了原代脾脏细胞的 Abil-1β 转录物。为了研究 AbIL-1β 的杀菌能力，通过原核生物生成了重组 AbIL-1β（rAbIL-1β）。在 A.h 感染后，rAbIL-1β 的预先注射减少了鲟鱼脾脏中的细菌负荷。此外，rAbIL-1β 被用作饲料添加剂，并通过增加免疫相关基因（白细胞介素-1β、白细胞介素-6、白细胞介素-8、IgM 和 MHCIIβ）的表达水平、提高血清溶酶体、ACH50 和 MPO 的活性以及提高存活率来增强杂交鲟对 A.h 感染的抵抗力。总之，目前的结果表明，AbIL-1β 在免疫调节中发挥作用，并可以提高鲟鱼对细菌感染的抵抗力。
