A novel C1qDC (PoC1qDC) with a collagen domain in Paralichthys olivaceus mediates complement activation and against bacterial infection.
A novel C1qDC (PoC1qDC) with a collagen domain in Paralichthys olivaceus mediates complement activation and against bacterial infection.
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DOI：
10.1016/j.fsi.2022.108472
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发表时间：
2022-12
影响因子：
4.7
通讯作者：
Mo-fei Li;Hong-qiang Zhang;Jin-sheng Sun
中科院分区：
文献类型：
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作者：
Mo-fei Li;Hong-qiang Zhang;Jin-sheng Sun
补体C1 q结构域蛋白（C1 qDC）是一种重要的识别分子，在免疫中起重要作用。C1 qDCs在鱼类中具有调理活性，但其在补体激活中的作用机制尚不清楚。本研究探讨了一种来自日本比目鱼（Paralichthys olivaceus）的C1 qDC（PoC 1 qDC）的免疫学特性。PoC 1 qDC由296个氨基酸残基组成，具有胶原结构域和C1 q结构域。根据我们的结果，PoC 1 qDC在9个不同的组织样品中表达，并在细菌攻击后显示上调。重组PoC 1 qDC（rPoC 1 qDC）通过与牙鲆IgM相互作用激活正常血清的杀菌和溶血活性，但不增强C3-去补体血清的补体活性。rPoC 1 qDC能与多种细菌结合，对杀鱼爱德华氏菌（Edwardsiella piscicida）和海豚链球菌（Streptococcus iniae）具有明显的凝集活性，并能与外周血白细胞直接结合，同时增强吞噬和趋化活性。当PoC 1 qDC在E.杀鱼素感染后，细菌在鱼组织中的复制被显著抑制。因此，当日本比目鱼中PoC 1 qDC的表达被敲低时，细菌的复制显著增强。上述研究结果首次表明，在硬骨鱼PoC 1 qDC介导的补体激活的作用，通过与IgM相互作用，这可以积极影响细菌感染。
Complement C1q domain containing protein (C1qDC) is a vital recognition molecule and has an important effect on immunity. The C1qDCs exhibit opsonic activity in fish, while the mechanisms of C1qDCs in activation complement still remain unclear. This study explored immunological characteristics of a C1qDC from Japanese flounder (Paralichthys olivaceus) (PoC1qDC). PoC1qDC consists of 296 amino acid residues, possessing a collagen domain and a C1q domain. According to our results, PoC1qDC was expressed in 9 diverse tissue samples and showed up-regulation after bacterial challenge. Recombinant PoC1qDC (rPoC1qDC) activated normal serum bactericidal and hemolytic activities by interaction with Japanese flounder IgM, but not enhanced the complement activity of C3-depeleted serum. rPoC1qDC was significantly bound to various bacterial species and agglutination activity againstEdwardsiella piscicidaandStreptococcus iniae.Furthermore, rPoC1qDC showed direct interaction with peripheral blood leucocytes while enhancing phagocytic and chemotactic activity. When PoC1qDC was overexpressed in Japanese flounder beforeE. piscicidainfection, bacterial replication was significantly inhibited in fish tissues. Consistently, when PoC1qDC expression in Japanese flounder was knocked down, bacterial replication was significantly enhanced. The above findings first suggested the role of PoC1qDC in teleost in mediating complement activation by interaction with IgM, which can positively influence bacterial infection.