ABSTRACT
B cell activating factor (BAFF), a ligand belonging to the tumor necrosis factor (TNF) family is critical to B cell survival, proliferation, maturation and immunoglobulin secretion. In this study, the yellow grouper (Epinephelus awoara) BAFF (designated EaBAFF) gene was cloned using RT-PCR and RACE (rapid amplification of cDNA ends) techniques. The full-length EaBAFF was 1442bp and contained an open reading frame of 780bp encoding a putative protein of 259 amino acids. Amino acids sequence comparison indicated that EaBAFF possessed the TNF signature. The soluble BAFF (EasBAFF) had been cloned into pET28a. SDS-PAGE and Western blotting analysis confirmed that the soluble fusion protein His-EasBAFF was efficiently expressed in Escherichia coli BL21 (DE3). In vitro, the WST-8 assay indicated that EasBAFF was not only able to promote the survival/proliferation of yellow grouper splenic lymphocytes but also able to promote the survival/proliferation of mouse splenic B cells. Our findings may provide valuable information for research into the immune system of E. awoara and EasBAFF may serve as a potential immunologic factor for enhancing immunological efficacy in fish.
Subject(s)
B-Cell Activating Factor/genetics , Fish Proteins/genetics , Gene Expression , Perciformes/genetics , Amino Acid Sequence , Animals , B-Cell Activating Factor/classification , B-Cell Activating Factor/metabolism , B-Lymphocytes/metabolism , Blotting, Western , Cloning, Molecular , Fish Proteins/metabolism , Mice , Microscopy, Confocal , Molecular Sequence Data , Perciformes/metabolism , Phylogeny , Protein Binding , Reverse Transcriptase Polymerase Chain Reaction , Sequence Homology, Amino Acid , Spleen/cytology , TranscriptomeABSTRACT
The presence of natural autoantibodies against cytokines has been reported in healthy individuals. Because circulating cytokines may be implicated in the clinical outcome of numerous diseases, the mode of action of intravenous immunoglobulin (IVIg) (pooled from sera over a thousand normal individuals) may involve immunomodulation of the cytokine network. We review the anti-cytokine effects of IVIg as well as the consequences of IVIg infusions on cytokine production. Furthermore, IVIg exerts therapeutic effects in autoimmune diseases and lymphoid malignancies. These two conditions have in common an overproduction of BAFF (for B-cell-activating factor of the TNF family). The presence of antibodies with BAFF and APRIL (a proliferation-inducing ligand) specificity was investigated. We found that IVIg recognizes BAFF and APRIL and that IVIg binding prevents BAFF from exerting its antiapoptotic effect on B cells. These anti-BAFF IgGs might prevent the deleterious effects of BAFF in B-cell-mediated autoimmune diseases.
