Interdisciplinary Graduate School of Agriculture and Engineering, University of Miyazaki, 1-1, Gakuen Kibanadai-nishi, 889-2192 Miyazaki, Japan.
Fish Shellfish Immunol. 2010 Apr;28(4):571-8. doi: 10.1016/j.fsi.2009.12.020. Epub 2010 Jan 1.
A tumor necrosis factor (TNF) gene has been isolated and characterized in kuruma shrimp, Marsupenaeus japonicus, providing the first conclusive evidence for the existence of the TNF ligand in shrimp. The kuruma shrimp TNF (MjTNF) cDNA was composed of 1868 bp with a 262 bp 5'-untranslated region (UTR) and a 220 bp 3'-UTR, which was translated into a protein of 462 amino acid residues that included a predicted transmembrane domain of 23 amino acid residues (Trp20-Val42) and the TNF family signature (Pro321-Leu448). Homology analysis of MjTNF showed 30.7% and 26.7% identities with fruit fly (Drosophila melanogaster) Eiger and human (Homo sapiens) ectodysplasin A, respectively. The MjTNF gene was constitutively expressed in unstimulated organs of shrimp such as the muscle, stomach, brain and gill. In lymphoid organ cells, an enhanced expression of the MjTNF gene was observed following stimulation with peptidoglycan and polycytidylic acid. A high expression level of MjTNF was observed in vivo 2 h and 4 h after stimulation with lipopolysaccharide and Vibrio penaeicida, respectively. These observations suggest that MjTNF plays a role in the innate immune defense in kuruma shrimp. The discovery of shrimp TNF will allow a more complete and concrete understanding of shrimp inflammatory responses.
肿瘤坏死因子 (TNF) 基因已在日本对虾中被分离并鉴定，这为虾类 TNF 配体的存在提供了第一个确凿的证据。日本对虾 TNF（MjTNF）cDNA 由 1868bp 组成，具有 262bp 的 5'-非翻译区（UTR）和 220bp 的 3'-UTR，可翻译成 462 个氨基酸残基的蛋白质，其中包括 23 个氨基酸残基的预测跨膜结构域（Trp20-Val42）和 TNF 家族特征（Pro321-Leu448）。MjTNF 的同源性分析显示，与果蝇（Drosophila melanogaster）Eiger 和人类（Homo sapiens）ectodysplasin A 的同源性分别为 30.7%和 26.7%。MjTNF 基因在虾的未刺激器官中持续表达，如肌肉、胃、脑和鳃。在淋巴器官细胞中，在肽聚糖和多聚胞嘧啶核苷酸刺激后，MjTNF 基因的表达增强。在受到脂多糖和副溶血弧菌刺激后 2 小时和 4 小时，体内观察到 MjTNF 的高表达水平。这些观察结果表明，MjTNF 在日本对虾的先天免疫防御中发挥作用。虾 TNF 的发现将使人们更全面、更具体地了解虾类的炎症反应。
