Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangzhou, 510631, PR China.
Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangzhou, 510631, PR China.
Dev Comp Immunol. 2021 Jan;114:103836. doi: 10.1016/j.dci.2020.103836. Epub 2020 Aug 22.
CXC chemokine receptor 4 (CXCR4), a member of seven-transmembrane (7-TM) G-protein-coupled receptor superfamily, is the receptor of the CXC chemokine ligand 12 (CXCL12), and plays important roles in host defense and inflammation. In the current study, we cloned and identified a homolog of CXCR4 from Nile tilapia (Oreochromis niloticus), designated as OnCXCR4. The open reading frame of OnCXCR4 is 1149 bp encoding a peptide of 382 amino acids, and the predicted molecular weight is 42.65 kDa OnCXCR4 shares common features of CXCR4 family, including a 7-TM domain and a characteristic CXC motif (containing CYC). Expression analysis showed that OnCXCR4 constitutively expresses in various tested tissues of Nile tilapia, with the highest level in the anterior kidney. When stimulated with Streptococcus agalactiae, Aeromonas hydrophila, Poly(I:C), or LPS in vivo and in vitro, the expression of OnCXCR4 was significantly regulated. AMD3100, a CXCR4 antagonist, could not only inhibit the chemotactic activity of the recombinant OnCXCL12 protein on the leukocytes from anterior kidney, but also reduce the expression of OnCXCR4 significantly. Taken together, these results of our study above indicate that OnCXCR4 may play important roles in host defense against bacterial infectionin in Nile tilapia, and being a receptor of OnCXCL12 to exert functions.
CXC 趋化因子受体 4（CXCR4）是七跨膜（7-TM）G 蛋白偶联受体超家族的成员，是 CXC 趋化因子配体 12（CXCL12）的受体，在宿主防御和炎症中发挥重要作用。在本研究中，我们从尼罗罗非鱼（Oreochromis niloticus）中克隆并鉴定了 CXCR4 的同源物，命名为 OnCXCR4。OnCXCR4 的开放阅读框为 1149 bp，编码 382 个氨基酸的肽，预测分子量为 42.65 kDa。OnCXCR4 具有 CXCR4 家族的共同特征，包括 7-TM 结构域和特征性 CXC 基序（含 CYC）。表达分析表明，OnCXCR4 在尼罗罗非鱼的各种测试组织中均持续表达，在前肾中表达水平最高。体内和体外用链球菌、嗜水气单胞菌、Poly(I:C)或 LPS 刺激后，OnCXCR4 的表达受到显著调节。AMD3100，一种 CXCR4 拮抗剂，不仅可以抑制重组 OnCXCL12 蛋白对前肾白细胞的趋化活性，还可以显著降低 OnCXCR4 的表达。综上所述，这些研究结果表明，OnCXCR4 可能在尼罗罗非鱼抵抗细菌感染的宿主防御中发挥重要作用，是 OnCXCL12 的受体并发挥功能。
