Sathyamoorthi Akila, Bhatt Prasanth, Ravichandran Gayathri, Kumaresan Venkatesh, Arasu Mariadhas Valan, Al-Dhabi Naif Abdullah, Arockiaraj Jesu
Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India; Department of Biotechnology, SRM Arts & Science College, Kattankulathur, Chennai 603 203, India.
Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India.
Vet Immunol Immunopathol. 2017 Aug;190:1-9. doi: 10.1016/j.vetimm.2017.06.008. Epub 2017 Jun 22.
Chemokines have been known for their wide range of functions including chemoattractant property in humans and other vertebrate organisms. They act as a bridge between innate and adaptive immune system. In the present study, we have identified a CXC chemokine from the cDNA library of C. striatus; on the basis of orthology study, it was found highly identical to interleukin 8 (IL8). The bioinformatics analysis of the chemokine revealed the presence of a typical γ-core domain and a CXC motif at the N-terminal region of the molecule. Based on the amphipathic nature at the C terminal helical region of CstIL8 and their antimicrobial propensity observed during bioinformatics analysis, a short peptide namely WS12 comprising 12 amino acid residues was predicted and synthesized to determine its antimicrobial activity. The peptide WS12 was active against Bacillus cereus, a Gram positive bacterium. Scanning electron microscopy (SEM) results showed bleb-like formation on the surface of the bacteria after the treatment of WS12. Additionally, WS12 did not exhibit any cytotoxic activity against the fish leukocytes. Further, the gene expression studies also revealed that CstIL8 was expressed significantly in liver of Channa striatus (Cst) at basal level. The immune challenge studies with pathogens and immune-stimulants revealed an increase in the mRNA levels at different time points post-challenge. Hence, it is possible to conclude that WS12 was a potent antimicrobial agent and it was significantly expressed during the pathogen stress.
趋化因子因其广泛的功能而闻名，包括在人类和其他脊椎动物中的趋化特性。它们在先天免疫系统和适应性免疫系统之间架起了一座桥梁。在本研究中，我们从条纹鲮鲤的cDNA文库中鉴定出一种CXC趋化因子；基于同源性研究，发现它与白细胞介素8（IL8）高度同源。对该趋化因子的生物信息学分析表明，在该分子的N端区域存在一个典型的γ核心结构域和一个CXC基序。基于CstIL8 C端螺旋区域的两亲性以及在生物信息学分析中观察到的抗菌倾向，预测并合成了一种由12个氨基酸残基组成的短肽WS12，以确定其抗菌活性。肽WS12对革兰氏阳性菌蜡样芽孢杆菌有活性。扫描电子显微镜（SEM）结果显示，用WS12处理后，细菌表面形成泡状结构。此外，WS12对鱼类白细胞没有任何细胞毒性活性。此外，基因表达研究还表明，CstIL8在条纹鲮鲤（Cst）肝脏的基础水平上有显著表达。对病原体和免疫刺激剂的免疫应激研究表明，在应激后的不同时间点，mRNA水平有所增加。因此，可以得出结论，WS12是一种有效的抗菌剂，在病原体应激期间有显著表达。
