CD154-CD40 Interactions Are Essential for Thymus-Dependent Antibody Production in Zebrafish: Insights into the Origin of Costimulatory Pathway in Helper T Cell-Regulated Adaptive Immunity in Early Vertebrates
CD154-CD40 Interactions Are Essential for Thymus-Dependent Antibody Production in Zebrafish: Insights into the Origin of Costimulatory Pathway in Helper T Cell-Regulated Adaptive Immunity in Early Vertebrates
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CD154-CD40 相互作用对于斑马鱼胸腺依赖性抗体产生至关重要：深入了解早期脊椎动物辅助 T 细胞调节的适应性免疫中共刺激途径的起源
DOI：
10.4049/jimmunol.0804370
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发表时间：
2009-06-15
影响因子：
4.4
通讯作者：
Shao, Jian-Zhong
中科院分区：
文献类型：
--
作者：
Gong, Yong-Feng;Xiang, Li-Xin;Shao, Jian-Zhong
CD 154-CD 40介导的共刺激通路在哺乳动物胸腺依赖性免疫应答中对T-B细胞合作至关重要。然而，很少有人知道它的存在和发生在低等脊椎动物。在这里，我们报告的CD 154和CD 40同源物从斑马鱼（Danio rerio）模型的识别和功能特性。斑马鱼CD 154是一种II型膜结合蛋白，在其胞外C-末端区域具有TNF同源结构域，其三级结构是包含具有“果冻卷”拓扑结构的两个堆叠片的三明治，就像人TNF成员一样。斑马鱼CD 40是一种I型膜结合蛋白，在其胞外N-末端区域具有四个富含半胱氨酸的结构域的序列模式。在哺乳动物CD 40中的共有TNFR相关因子（TRAF）2-和TRAF 6-结合基序在斑马鱼CD 40的胞质尾中发现，这表明与高等脊椎动物相似的信号转导机制。斑马鱼CD 154和CD 40广泛分布，可被胸腺依赖性Ag上调。抗CD 154或可溶性CD 40可显著降低IgM的产生，而可溶性CD 154或编码CD 154的质粒可增强IgM的产生。胸腺依赖性Ag诱导的CD 154表达被环孢菌素A抑制，表明CD 154与T细胞功能相关。免疫荧光双标显示，CD 40和膜IgM共定位于B细胞。CD 154-CD 40结合试验显示，CD 154以同源二聚体形式特异性结合CD 40。我们的研究结果提供了第一个证据的存在的功能性CD 154-CD 40介导的共刺激途径和辅助性T细胞调节机制的适应性免疫的鱼类物种。免疫学杂志，2009，182：7749-7762.
The CD154-CD40-mediated costimulatory pathway is critical for T-B cell cooperation in thymus-dependent (TD) immune response in mammals. However, little is known about its existence and occurrence in lower vertebrates. Here, we report on the identification and functional characterization of CD154 and CD40 homologs from the zebrafish (Danio rerio) model. Zebrafish CD154 is a type II membrane-bound protein with a TNF homology domain in its extracellular C-terminal region, whose tertiary structure is a sandwich containing two stacked sheets with "jelly roll" topology, just as the human TNF members do. The zebrafish CD40 is a type I membrane-bound protein with a sequence pattern of four cysteine-rich domains in its extracellular N-terminal region. The consensus TNFR-associated factor (TRAF)2- and TRAF6-binding motifs in mammalian CD40 are found in the cytoplasmic tail of zebrafish CD40, which indicates similar signal transduction mechanisms to higher vertebrates. Zebrafish CD154 and CD40 are widely distributed and can be up-regulated by thymus-dependent Ag. The production of IgM was dramatically decreased by anti-CD154 or soluble CD40, and it was enhanced by soluble CD154 or CD154-encoding plasmid in vivo. Thymus-dependent Ag-induced CD154 expression was inhibited by cyclosporin A, suggesting that CD154 functionally associates with T cells. Double immunofluorescence staining showed that CD40 and membrane IgM colocalized in B cells. CD154-CD40 binding assays showed that CD154 specifically binds to CD40 at homodimeric form. Our results provide the first evidence for the existence of the functional CD154-CD40-mediated costimulatory pathway and helper T cell regulatory mechanism underlying adaptive immunity in a fish species. The Journal of Immunology, 2009, 182: 7749-7762.