Identification of a TGF-β1 homologue in the large yellow croaker(Larimichthys crocea)revealed its role in regulation of immune response  

作　　者：Xiaofeng Li Pengfei Mu Yan Teng Xiaomeng Li Yinanzi Wu Xinhua Chen 

机构地区：[1]Key Laboratory of Marine Biotechnology of Fujian Province,Institute of Oceanology,Fujian Agriculture and Forestry University,Fuzhou,350002,China [2]Laboratory for Marine Biology and Biotechnology,Qingdao National Laboratory for Marine Science and Technology,Qingdao,266071,China [3]Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai,519000,China

出　　处：《Water Biology and Security》2022年第1期53-62,共10页水生生物与安全（英文）

基　　金：funded by the National Natural Science Foundation of China(U1905204);China Agricultural Research System of MOF and MARA(CARS-47);Fujian Science and Technology Department(2021N5008);Institute of Oceanology of Fuzhou(2021F02).

摘　　要：Mammalian TGF-β1 plays a crucial role in maintaining immune tolerance and inhibiting autoimmunity.Although several TGF-β1 homologues have been identified in teleosts,their immunosuppressive functions remain unclear.Herein,we identified and characterized LcTGF-β1,a TGF-β1 homologue from the large yellow croaker(Larimichthys crocea).LcTGF-β1 possesses several features characteristic of the TGF-βsuperfamily,including an RGD integrin binding site,an RSKR tetrabasic cut site,and nine conserved cysteines in the mature peptide.The LcTGFβ1 gene was constitutively expressed in all examined tissues,with the highest expression in the spleen,which is rich in immune cells.LcTGF-β1 was significantly upregulated in the head kidney and spleen after Vibrio alginolyticus stimulation.LcTGF-β1 was also expressed in primary head kidney lymphocytes(PKLs),monocytes/macrophages(MO/Mφs),and granulocytes(PKGs),and was significantly upregulated in the MO/Mφs after lipopolysaccharide(LPS)stimulation.Recombinant LcTGF-β1 protein(rLcTGF-β1)significantly suppressed reactive oxygen species(ROS)and nitrogen oxide(NO)production in LPS-activated head kidney MO/Mφs.Furthermore,in these MO/Mφs,rLcTGF-β1 strongly inhibited the expression of pro-inflammatory cytokine(TNFα)and inducible NO synthase(iNOS),while it induced anti-inflammatory cytokines(TGF-β1 and IL-10),arginase1,and CD206.The phagocytic activity of LPS-activated MO/Mφs was also increased by rLcTGF-β1.Finally,rLcTGF-β1 significantly inhibited the proliferation of T cells(ZAP70þcells)and downregulated T-cell activation genes(CD3ζ,TCRα,and ZAP70),T-cell marker genes(CD4 and CD8),and IL-2 in PKLs.These results thus provide strong evidence that LcTGF-β1 promotes the alternative activation of head kidney MO/Mφs and inhibits T-cell proliferation in PKLs,highlighting its role in the regulation of immune response in large yellow croaker.

关 键 词：Large yellow croaker TGF-Β1 Monocytes/macrophage T cells IMMUNOREGULATION 

分 类 号：Q178.1[生物学—水生生物学]