Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, Guangdong, China.
Fish Physiol Biochem. 2013 Jun;39(3):459-69. doi: 10.1007/s10695-012-9711-4. Epub 2012 Sep 7.
Chemokines are small, secreted cytokine peptides known principally for their ability to induce migration and activation of leukocyte populations and regulate the immune response mechanisms. The cobia (Rachycentron canadum), a marine finfish species, has a great potential for net cage aquaculture in the South China Sea. We isolated and characterized a CC chemokine cDNA from cobia-designated RcCC2. Its cDNA is 783 bp in length and encodes a putative protein of 110 amino acids. Homology and phylogenetic analysis revealed that the RcCC2 gene, which contains four conserved cysteine residues, shares a high degree of similarity with other known CC chemokine sequences and is closest to the CCL19/21 clade. The mRNA of RcCC2 is expressed constitutively in all tested tissues, including gill, liver, muscle, spleen, kidney, head kidney, skin, brain, stomach, intestine and heart, but not blood, with the highest level of expression in gill and liver. The reverse transcription quantitative polymerase chain reaction was used to examine the expression of the RcCC2 gene in immune-related tissues, including head kidney, spleen and liver, following intraperitoneal injection of the viral mimic polyriboinosinic polyribocytidylic acid, formalin-killed Vibrio carchariae (bacterial vaccine) and phosphate-buffered saline as a control. RcCC2 gene expression was up-regulated differentially in head kidney, spleen and liver during 12 h after challenge. These results indicate that the RcCC2 gene is inducible and is involved in immune responses, suggesting RcCC2 has an important role in the early stage of viral and bacterial infections.
趋化因子是小的分泌细胞因子肽，主要因其诱导白细胞群体迁移和激活以及调节免疫反应机制的能力而闻名。石斑鱼（Rachycentron canadum）是一种海洋鱼类，在中国南海有很大的网箱养殖潜力。我们从石斑鱼中分离并鉴定了一种 CC 趋化因子 cDNA，命名为 RcCC2。其 cDNA 长度为 783bp，编码一个由 110 个氨基酸组成的假定蛋白。同源性和系统发育分析表明，RcCC2 基因包含四个保守的半胱氨酸残基，与其他已知的 CC 趋化因子序列具有高度相似性，与 CCL19/21 分支最为接近。RcCC2 的 mRNA 在所有检测的组织中均呈组成型表达，包括鳃、肝、肌肉、脾、肾、头肾、皮肤、脑、胃、肠和心脏，但血液中不表达，在鳃和肝中表达水平最高。采用反转录定量聚合酶链反应检测了病毒模拟物聚肌胞苷酸、福尔马林灭活哈维弧菌（细菌疫苗）和磷酸盐缓冲盐水（作为对照）腹腔注射后免疫相关组织（头肾、脾和肝）中 RcCC2 基因的表达。在挑战后 12h 内，头肾、脾和肝中 RcCC2 基因的表达呈差异上调。这些结果表明，RcCC2 基因是可诱导的，参与免疫反应，表明 RcCC2 在病毒和细菌感染的早期阶段具有重要作用。
