Cloning and expression of TIRAP gene and immune response in Nile tilapia Oreochromis niloticus to Streptococcus agalactiae, lipopolysaccharides and polyinosinic polycytidylic acid stress
LIU Jie1,2, GAO Fengying1*, LU Maixin1*, CHEN Gang2, CAO Jianmeng1, LIU Zhigang1, WANG Miao1, HAN Xueqing1,3
1. Key Laboratory of Tropical & Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Science, Guangzhou 510380, China; 2.College of Fisheries, Guangdong Ocean University, Zhanjiang 524025, China; 3.College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China
Abstract: The cDNA sequence of TIR domain-containing adaptor protein (TIRAP) gene, as an important adaptor protein molecule in the TLR signaling pathway, was cloned in Nile tilapia Oreochromisniloticus with body weight of 20-40 g by reverse transcription PCR and fragment amplification, and bioinformatics was also analyzed. The TIRAP gene was expressed in liver, skin, heart, kidney, stomach, gill, brain, spleen, intestine, blood and muscle of healthy Nile tilapia intraperitoneally injected with PBS solution, and intestine, gill, spleen, kidncy and blood of Nile tilapia intraperitoneally injected with Streptococcusagalactiae at a dose of 200 μL (3×107 CFU/mL) in 0 h, 8 h, 1 d, 2 d, 3 d, 6 d and 9 d by RT-qPCR. The TIRAP gene was expressed in liver, spleen, kidney, and intestine of healthy Nile tilapia intraperitoneally injected with lipopolysaccharides (LPS) and polyinosinic polycytidylic acid (100 μL of Poly I:C solution) in 0 h, 8 h, 1 d, 2 d, 3 d, 4 d and 5 d in order to investigate the regulatory role of TIRAP in TLR signaling-mediated innate immunity in Nile tilapia. It was found that the TIRAP cDNA was 2 900 bp in length and contained an ORF of 816 bp encoding 291 amino acid residues. The phylogenetic tree indicated that TIRAP gene of Nile tilapia was closely related to Astatotilapiacalliptera TIRAP gene. The expression of TIRAP was detected in all the tissues and organs tested, with the maximal expression level in the muscle(P<0.05) and the minimal expression level in the stomach. TIRAP gene expression was up-regulated in the intestine and kidney of the Nile tilapia challenged with S.agalactiae, with the peak at 24 h post infection (hpi). TIRAP gene was up-regulated in the liver, spleen, and kidney of the Nile tilapia challenged with LPS and Poly I:C. However, the expression level of TIRAP in the intestine was down-regulated when compared with the control group (0 h group). The findings indicated that the TIRAP gene expression was induce by S.agalactiae, LPS and Poly I:C, which was involved in the immune response of Nile tilapia, and thus the TIRAP played a role in innate immunity, which provides a new ideas for further exploration of the immune response mechanism of TIRAP and its role in the TLR signaling pathway.
刘洁、, 高风英, 卢迈新, 陈刚, 曹建萌, 刘志刚, 王淼, 韩雪晴、. 尼罗罗非鱼TIRAP基因克隆、组织表达及其在无乳链球菌、脂多糖和聚肌胞苷酸刺激下的免疫应答[J]. 大连海洋大学学报, 2020, 35(6): 857-865.
LIU Jie, GAO Fengying, LU Maixin, CHEN Gang, CAO Jianmeng, LIU Zhigang, WANG Miao, HAN Xueqing, . Cloning and expression of TIRAP gene and immune response in Nile tilapia Oreochromis niloticus to Streptococcus agalactiae, lipopolysaccharides and polyinosinic polycytidylic acid stress. Journal of Dalian Ocean University, 2020, 35(6): 857-865.
2020, Vol. 35 
