论文部分内容阅读
趋化因子(chemokine)是一类能够吸引白细胞移行到感染部位的低分子量(8-10ku)的蛋白质,在炎症反应、非特异性免疫反应中具有重要作用。实验克隆了剑尾鱼2个趋化因子基因(CCL4、CCL19)cDNA序列,运用荧光定量PCR技术检测其在健康组织和嗜水气单胞菌感染后肝、脾中的表达情况。结果显示,剑尾鱼CCL4和CCL19开放阅读框(Open Reading Frame,ORF)长度分别为294 bp和333 bp,分别编码97和110个氨基酸,推导氨基酸序列均含有趋化因子CC家族标志性的4个半胱氨酸残基,与其他物种尼罗罗非鱼、鼠、狗、人、鸡的氨基酸序列相似性比较,CCL4基因相似度分别为71.1%、33%、33%、31%、23.5%;CCL19基因相似度分别为62%、26.9%、24.5%、26.6%、27.8%。在检测的健康剑尾鱼8个组织中,CCL4和CCL19均有表达,其中CCL4和CCL19均在脾脏中表达量最高;CCL4在肌肉和肠中表达量较低,而CCL19则在心脏中表达量较低。经嗜水气单胞菌感染后,CCL4在剑尾鱼头肾中12 h表达量达到最高,在肝脏中24 h表达量最高;CCL19在头肾和肝脏均在24 h时表达量最高。研究表明,趋化因子CCL4和CCL19可能参与剑尾鱼机体免疫调节反应,在抗嗜水气单胞菌感染过程中发挥了重要作用。
Chemokines, a class of low-molecular-weight proteins (8-10 ku) that attract white blood cells to the site of infection, play an important role in inflammation and nonspecific immune responses. The cDNA sequences of two chemokine genes (CCL4 and CCL19) from the swordtail fish were cloned and the expression of CCL4 and CCL19 in the liver and spleen of healthy tissues and Aeromonas hydrophila was detected by real-time fluorescence quantitative PCR. The results showed that the length of open reading frame (ORF) of CCL4 and CCL19 was 294 bp and 333 bp, encoding 97 and 110 amino acids, respectively. The deduced amino acid sequences all contained the signature 4 of chemokine CC family The similarity of amino acid sequence of CCL4 gene was 71.1%, 33%, 33%, 31%, 23.5%, respectively, compared with other species of Nile tilapia, mouse, dog, human and chicken %; CCL19 gene similarity were 62%, 26.9%, 24.5%, 26.6%, 27.8% respectively. CCL4 and CCL19 were expressed in 8 tissues of healthy Swordfish, of which CCL4 and CCL19 were all expressed the highest in spleen; CCL4 was lower in muscle and intestine and CCL19 was expressed in heart Lower. After infected with Aeromonas hydrophila, the expression level of CCL4 reached the peak at 12 h in the head tail kidney of JF-boat and highest at 24 h in the liver. CCL-19 was the highest expression in the head kidney and liver at 24 h. Studies have shown that the chemokines CCL4 and CCL19 may be involved in the immune regulation of the body of Swordfish, and play an important role in the resistance to Aeromonas hydrophila infection.