Cloning, Expression And Biological Function Of Porcine Porcine Proliferation - Inducing Ligand (APRIL) Gene And γ - IFN - Induced Lysosomal Thiol Reductase (GILT) Gene

Section one. In this study, a proliferation inducing ligand (APRIL) belonging to the TNF family is critical for immune regulation. In this study, we identified a finless porpoise APRIL cDNA (fAPRIL) by RACE strategies. This gene encodes 247 amino acids which contains a predicted transmembrane domain and a TNF domain. Recombinant soluble fAPRIL (pET43.1a-fsAPRIL) fused with Nus-his6 tag was efficiently expressed in Escherichia coli BL21 (DE3). Phylogenetic analysis indicated the finless porpoises have a closely relationship with artiodactyla. In vitro, soluble fAPRIL (fsAPRIL) not only could promote the survival/proliferation of the mouse spleen lymphocytes with anti-IgM and but also could bind to the surface of the B cells specially. Section two.In this study, we isolated the cDNA of a gamma-interferon-inducible lysosomal thiol reductase (GILT), which is critical for innate immune regulation, from the Yangtze finless porpoise (FpGILT). This gene encoded a protein with 244 amino acids and a predicted molecular weight of 28 kDa. The amino acid sequence of FpGILT includes an active-site CXXC motif, a GILT signature sequence, CQHGX2ECX2NX4C, and three N-linked glycosylation sites. Phylogenetic analysis showed that FpGILT and other GILT family members were derived from a common ancestor and finless porpoises are closely related to Artiodactyla. Recombinant protein (FpsGILT) was then efficiently expressed and purified, and thiol reductase activity assays suggested that FpGILT catalyses disulfide bond reduction. These results about fAPRIL and FpGILT gene would provide a basis for understanding the characteristics of adaptive immune and innate immunity in the finless porpoise and other aquatic mammals.