Lane 1, protein markers.(TIF) pone.0136015.s002.tif (360K) GUID:?7F44B81E-E89E-4B1C-A739-E69CF8E3000D S3 Fig: Detection of plasmids (A) and expression of plasmid-derived (B) in tongue sole. RT-PCR with primers specific to plasmid-derived (upper panel), or, as an internal control, to -actin (lower panel). Lane 1 of both panels, DNA molecular weight markers.(TIF) pone.0136015.s003.tif (376K) GUID:?15A89507-FA70-4495-A942-3DCB9292987A S4 Fig: Expression of in psiCsBAFF-administered fish. Tongue sole were administered with psiCsBAFF, psiCsBAFF-C, or PBS (control), and expression in kidney and spleen was determined by quantitative real time RT-PCR at 7 days post-plasmid administration. In both tissues, the expression level of the control fish was set as 1. Values are shown as means SEM (N = 3). N, the number of times the experiment was performed. *< 0.05.(TIF) pone.0136015.s004.tif (612K) GUID:?82695E97-A9D1-44E7-A298-843BD1891CBB S5 Fig: Expression of the vaccine gene in vaccinated fish. Tongue sole were vaccinated with pCEsa1 + pCsBAFF (lanes 2 and 4), pCsBAFF (lane 3), pCEsa1 (lane 5), and pCN3 (lanes 6 and 7). At 7 days post-vaccination, RNA was extracted from Fangchinoline spleen and used for RT-PCR with primers specific to plasmid-derived (lanes 2, 3, and 6), (lanes 4, 5, and 7), or, as an internal control, to -actin (B). Lane 1 of both panels, DNA molecular weight markers.(TIF) pone.0136015.s005.tif (288K) GUID:?CFE015F8-B97A-48DF-ABEF-7A2E564E8D52 S6 Fig: Serum antibody production in vaccinated fish. Sera were taken from tongue sole vaccinated with pCEsa1, pCEsa1 plus pCsBAFF, and PBS (control) for one month. Serum antibodies against Esa1 were determined by enzyme-linked immunosorbent assay. Values are shown as mean SEM (N = 3). N, the number of times the assay was performed. **< 0.01; *< 0.05.(TIF) pone.0136015.s006.tif (488K) GUID:?C9BD6D03-7385-43C7-A795-E9C30E83E40A Data Availability StatementAll relevant data are within the paper and its Supporting Information files. Abstract B cell activating factor (BAFF) is a member of the tumor necrosis factor family that is known to play an important role in B cell activation, proliferation, and differentiation in mammals. However, studies of BAFF in teleosts are very limited and its function, in particular that under conditions, is essentially unknown. In this study, we conducted as well as functional analyses of a BAFF homologue (CsBAFF) from the teleost fish tongue sole (expression was most abundant in immune organs and was upregulated during bacterial infection. Purified recombinant CsBAFF (rCsBAFF) bound to tongue sole lymphocytes and promoted cellular proliferation and survival. The results of Fangchinoline an study showed that CsBAFF overexpression in tongue sole significantly enhanced macrophage activation and reduced bacterial infection in fish Fangchinoline tissues, whereas knockdown of expression resulted in increased bacterial dissemination and colonization in fish tissues. Furthermore, vaccination studies showed that CsBAFF enhanced the immunoprotection of a DNA vaccine and augmented the production of specific serum antibodies. Taken together, these results provide the first evidence to indicate that teleost BAFF is an immunostimulator that significantly contributes to the innate antibacterial immune response and vaccine-induced adaptive immune response. Introduction B-cell activating factor (BAFF), also known as BLys, TALL-1, THANK, zTNF4, and TNFSF13b, is a member of the tumor necrosis factor (TNF) family, and is mainly produced by innate immune cells, such as neutrophils, monocytes, and dendritic cells (DCs), as well as activated T cells and malignant B cells [1C7]. BAFF exists either as a type II transmembrane protein on the cell surface or a soluble protein after cleavage at the cell surface by a furin-like Mouse monoclonal to AXL protease [1,2]. BAFF exerts its function by interaction with its receptor. To date, three BAFF binding receptors have been identified, i.e., transmembrane activator and CAML interactor (TACI), B-cell maturation antigen (BCMA), and BAFF-R [8,9]. TACI and BCMA can also bind to a proliferation-inducing ligand (APRIL), another member of the TNF family that shares a high level of sequence similarity with BAFF [10,11], while BAFF-R is specific for BAFF. Recent studies suggest that BAFF-R may be the principal receptor responsible for B-cell development and survival [9]. Several lines of evidence have indicated that BAFF is involved in the regulation and promotion of both innate and adaptive immune responses. In mammals, BAFF plays a major role in B cell.