Molecular Characterization Of TNFR11B And Its Role In Against Vibrio Alginolyticus In Large Yellow Croaker(larimichthys Crocea)

Tumor necrosis factor receptor 11B(TNFR11B)is a member of the tumor necrosis factor receptor superfamily,contributing to inflammation,tumorigenesis,apoptosis,and differentiation.Here,we cloned the c DNA of the Lc TNFR11 B gene from large yellow croaker.To investigate the mechanism of TNFR11 B in regulating large yellow croaker(Larimichthys crocea)immune response to Vibrio alginolyticus,the large yellow croaker TNFR11B(Lc TNFR11B)c DNA sequence was downloaded from NCBI.Lc TNFR11 B was in total length of 2,359 bp and contained an Open Reading Frame(ORF)of 1,233 bp which encoded a protein of 410 aa with the molecular weight of 46.13 k Da.The amino acid of Lc TNFR11 B was relatively conservative,and shared 87.8% identity with barramundi(Lates calcarifer).RT-q PCR showed that Lc TNFR11 B m RNA expression was in a high level in head kidney,body kidney and spleen in healthy large yellow croaker.Lc TNFR11 B was upregulated at different time points post V.alginolyticus infection in head kidney,spleen,liver and monocytes/macrophage,while V.alginolyticus infection had no effect on the expression of Lc TNFR11 B level in gill.Furthermore,Lc TNFR11 B protein was expressed and purified using prokaryotic expression system,and the monocytes/macrophage were incubated with r Lc TNFR11 B.The results showed that r Lc TNFR11 B inhibited the expression of interleukin-1β(IL-1β)and tumor necrosis factor-α(TNF-α)in V.alginolyticus-infected monocytes/macrophage,and the expression of interleukin-10(IL-10)was promoted,while the expression of transforming growth factor-β(TGF-β)was not significantly affected.r Lc TNFR11 B decreased V.alginolyticus-induced apoptosis in monocytes/macrophage.Finally,we found that the expression of nuclear factor of activated t-cells cytoplasmic 1(NFATc-1),Cathepsin K(Ctsk)and c-Fos were decreased by r Lc TNFR11 B in V.alginolyticus-infected monocytes/macrophage.Therefore,the results indicate that Lc TNFR11 B might function in large yellow croaker immune responses by suppressing MO/MΦ inflammation,apoptosis,or differentiation.