School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, Zhejiang, China; Department of Physiology, and Department of Hepatobiliary and Pancreatic Surgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, Zhejiang, China.
Hangzhou Medical College, Hangzhou, 310013, Zhejiang, China.
Dev Comp Immunol. 2023 Aug;145:104726. doi: 10.1016/j.dci.2023.104726. Epub 2023 May 5.
Piscidins participate in the innate immune response of fish, which aims to eliminate recognized foreign microbes and restore the homeostasis of immune system. We characterized two piscidin-like antimicrobial peptides (LjPL-3 and LjPL-2) isolated from Japanese sea bass (Lateolabrax japonicus). LjPL-3 and LjPL-2 showed different expression patterns in tissues. After Vibrio harveyi infection, the mRNA expression of LjPL-3 and LjPL-2 was upregulated in the liver, spleen, head kidney, and trunk kidney. The synthetic mature peptides LjPL-3 and LjPL-2 exhibited different antimicrobial spectra. Furthermore, LjPL-3 and LjPL-2 treatments decreased inflammatory cytokine production while promoting chemotaxis and phagocytosis in monocytes/macrophages (MO/MФ). LjPL-2, but not LjPL-3, displayed bacterial killing capability in MO/MФ. LjPL-3 and LjPL-2 administration increased Japanese sea bass survival after V. harveyi challenge, which was accompanied by a decline in bacterial burden. These data suggested that LjPL-3 and LjPL-2 participate in immune response through direct bacterial killing and MO/MФ activation.
鱼体内的抗菌肽参与先天免疫反应，旨在消除被识别的外来微生物并恢复免疫系统的体内平衡。我们从鲈鱼（Lateolabrax japonicus）中分离出两种抗菌肽样抗菌肽（LjPL-3 和 LjPL-2），并对其进行了表征。LjPL-3 和 LjPL-2 在组织中表现出不同的表达模式。在哈维弧菌感染后，肝、脾、头肾和体肾中 LjPL-3 和 LjPL-2 的 mRNA 表达上调。合成的成熟肽 LjPL-3 和 LjPL-2 表现出不同的抗菌谱。此外，LjPL-3 和 LjPL-2 处理可降低单核细胞/巨噬细胞（MO/MФ）中炎症细胞因子的产生，同时促进其趋化和吞噬作用。LjPL-2 而非 LjPL-3 在 MO/MФ 中具有杀菌能力。LjPL-3 和 LjPL-2 的给药可增加鲈鱼在哈维弧菌攻毒后的存活率，同时降低细菌负荷。这些数据表明，LjPL-3 和 LjPL-2 通过直接杀菌和 MO/MФ 激活参与免疫反应。
