Swain Banikalyan, Basu Madhubanti, Lenka Saswati S, Das Surajit, Jayasankar Pallipuram, Samanta Mrinal
1 Fish Health Management Division, Central Institute of Freshwater Aquaculture (CIFA) , Bhubaneswar, Odisha, India .
DNA Cell Biol. 2015 May;34(5):367-78. doi: 10.1089/dna.2014.2656. Epub 2015 Mar 10.
Interferon gamma (IFN-γ) is one of the key cytokines that plays a major role against viral and intracellular bacterial infection. In addition to the IFN-γ gene, teleost fish possess a second copy known as IFN-γ-related (IFN-γrel) gene. This report describes structural and functional properties of IFN-γrel gene in the Indian major carp, rohu (Labeo rohita), a commercially important freshwater fish species in the Indian subcontinent. The rohu IFN-γrel gene consisted of four exons with three intervening introns and phylogenetically closely related to grass carp. The full-length IFN-γrel cDNA comprised 927 bp nucleotides with a single open reading frame of 504 bp, encoding 167 amino acids (aa) polypeptide with a signal peptide of 24 aa. The mature rohu IFN-γrel protein was 143 aa with a predicted molecular weight of 16.85 kDa. Basal expression analysis of IFN-γrel showed its wide range of expression in all examined tissues: The highest was in the skin and the lowest was in the liver. In response to LPS, poly I:C, iE-DAP, muramyl dipeptide stimulations, and bacterial infections, IFN-γrel gene expression was significantly (p<0.05) induced in treated fish tissues as compared with their control. The IFN-γrel was expressed as recombinant protein (rIFN-γrel) and confirmed through western blot. Stimulation of peripheral blood leukocytes with rIFN-γrel protein resulted in the activation of IFN-γ receptor and marked induction of inducible nitric oxide synthase gene expression. These results together may suggest the important role of IFN-γrel as an antimicrobial cytokine in fish.
干扰素γ（IFN-γ）是对抗病毒和细胞内细菌感染起主要作用的关键细胞因子之一。除了IFN-γ基因外，硬骨鱼还拥有第二个拷贝，即IFN-γ相关（IFN-γrel）基因。本报告描述了印度主要鲤鱼——印度鲤（Labeo rohita）中IFN-γrel基因的结构和功能特性，印度鲤是印度次大陆一种具有重要商业价值的淡水鱼品种。印度鲤IFN-γrel基因由四个外显子和三个间隔内含子组成，在系统发育上与草鱼密切相关。全长IFN-γrel cDNA由927个碱基对组成，有一个504个碱基对的单一开放阅读框，编码一个含24个氨基酸信号肽的167个氨基酸多肽。成熟的印度鲤IFN-γrel蛋白有143个氨基酸，预测分子量为16.85 kDa。IFN-γrel的基础表达分析表明其在所有检测组织中广泛表达：最高表达于皮肤，最低表达于肝脏。在脂多糖、聚肌胞苷酸、iE-DAP、胞壁酰二肽刺激以及细菌感染后，与对照相比，处理后鱼组织中IFN-γrel基因表达显著（p<0.05）上调。IFN-γrel表达为重组蛋白（rIFN-γrel）并通过蛋白质免疫印迹法得以证实。用rIFN-γrel蛋白刺激外周血白细胞导致IFN-γ受体激活并显著诱导诱导型一氧化氮合酶基因表达。这些结果共同表明IFN-γrel作为鱼类中的一种抗菌细胞因子具有重要作用。
