Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China.
International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 201306, China.
Cells. 2023 Sep 14;12(18):2276. doi: 10.3390/cells12182276.
Interleukin (IL) 21 is a pleiotropic cytokine that plays an important role in regulating innate and adaptive immune responses. In fish, the biological functions and cell source of IL-21 remain largely unknown. In this study, we performed qRT-PCR, Western blotting and immunofluorescent microscopy to examine the expression of IL-21 at the mRNA and protein levels. We found that expression was induced in the primary head kidney leukocytes of grass carp () by heat-inactivated () and LPS and in tissues after infection with . Recombinant IL-21 protein produced in the CHO-S cells was effective in elevating the expression of antibacterial genes, including and , and, interestingly, inhibited the NF-κB signaling pathway. Furthermore, we investigated the response of the IL-21 expressing cells to infection. Immunofluorescent assay showed that IL-21 protein was detected in the CD3γ/δ T cells and was markedly accumulated in the anterior, middle and posterior intestine. Collectively, the results indicate that IL-21 plays an important role in regulating the intestinal inflammation induced by bacterial infection in grass carp.
白细胞介素 (IL) 21 是一种多功能细胞因子，在调节先天和适应性免疫反应中发挥重要作用。在鱼类中，IL-21 的生物学功能和细胞来源在很大程度上仍不清楚。在这项研究中，我们通过 qRT-PCR、Western blot 和免疫荧光显微镜检查了草鱼（）主要头部肾脏白细胞中 IL-21 在 mRNA 和蛋白质水平上的表达。我们发现，热灭活的（）和 LPS 可诱导草鱼头部肾脏白细胞中 表达，感染后组织中也可诱导 表达。在 CHO-S 细胞中产生的重组 IL-21 蛋白可有效上调抗菌基因，包括 和 ，有趣的是，它还抑制了 NF-κB 信号通路。此外，我们研究了表达 IL-21 的细胞对 感染的反应。免疫荧光检测表明，在 CD3γ/δ T 细胞中检测到 IL-21 蛋白，并且在前、中、后肠中明显积累。综上所述，结果表明 IL-21 在调节草鱼细菌感染引起的肠道炎症中发挥重要作用。
