In order to study the biological function of pig BST-2 gene,the BST-2 gene was amplified with specific primers from porcine kidney tissue,and molecular characterization of BST-2 nuclectide and amino acid sequence were analyzed with bioinformatics tools and online server.Then the prokaryotic expression and tissue expression profile analysis was carried out.The results showed that the full length of pig BST-2 gene was 851 bp and contained 23 bp of 5'-UTR,294 bp of 3'-UTR and 534 bp of CDS and the gene encoded 177 aa.Amino acid sequence analysis of pig BST-2 protein showed 46.1％ identity with gorilla gorilla,41.7％ with cricetulus griseus,39.5％ with mus musculus,35.4％ with equus asinus,42.0％ with felis catus,40.5％ with bos mutus,44.4％ with macaca mulatta,38.7％ with ovis aries and 46.8％ with homo sapiens.BST-2 protein contained 2 transmembrane structure (27-49 aa and 154-176 aa),2 glycosylation sites and 14 potential phosphorylation sites including ATM,CK Ⅱ,PKA,PKC binding sites.The pig BST-2 protein was expressed in Vero cells after translated the recombinant plasmid FLAG-BST-2.Semiquantitative PCR results showed that BST-2 gene was expressed in all the tissues,especially in lymph nodes,thymus,tonsils,spleen,large intestine and small intestine.This study provide a foundation for further understanding the antiviral mechanism of pig BST-2 protein.

Previous studies suggest that NGAL (neutro phil gelatinase-associated lipocalin) is involved in the transformation and development of esophageal carcinoma. Alteration of NGAL expression can trigger the change of cellular morphology in esophageal carcinoma cells. However, the mechanisms remain unclear. To get a better understanding of NGAL function in esophageal carcinoma, NGAL protein was expressed in methylotrophic yeast, Pichia pastoris, and purified by chromatography. EC1.71 cells expressed high levels of NGALR (NGAL receptor) and EC109 cells expressed low levels of NGALR were used as cells model. The trafficking and the possible function of NGAL protein were then analyzed in the esophageal carcinoma cells. The results showed that 5-FAM-labeled recombinant NGAL protein could internalize into the EC1.71 and EC109 cells. Furthermore, the internalized NGAL protein could induce the alteration of cellular morphology, resulting in generation of autophagosome, transcriptional up-regulation of genes associated with autophagy and increase of phospho-ERK1/2 (p-ERK1/2). Interestingly, the treatment with the NGAL protein did not affect the intracellular iron level. These data indicate that induced autophagy by exogenous NGAL protein is a mechanism that internalized NGAL plays important roles in esophageal carcinoma cells, independent with NGAL-mediated iron transport process, while ERK1/2 signal pathway is involved in activation of autophagy by exogenous NGAL protein.

A simple and rapid immunochromatographic test strip incorporating a colloidal gold-labeled recombinant Nsp7 antigen probe was successfully developed for the detection of anti-porcine reproductive and respiratory syndrome virus (PRRSV) antibodies in swine. Recombinant Nsp7 protein of PRRSV labeled with colloidal gold was dispensed on a conjugate pad for use as the detector. Staphylococcal protein A and purified porcine anti-Nsp7 antibodies were blotted on a nitrocellulose membrane to form test and control lines, respectively. A comparison of the strip with standard diagnostic tests, enzyme-linked immunosorbent assays and immunoperoxidase monolayer assay, was also performed. The immunochromatographic test strip was shown to be of high specificity and sensitivity. Furthermore, the strip assay is rapid and easy to perform with no requirement for professional-level skills or equipment. It is suggested that the immunochromatographic test strip can be used to quickly and accurately detect PRRSV antibody and to be suitable for diagnostic purposes in the field.
Antibodies* ; Collodion ; Colloids ; Diagnostic Tests, Routine ; Enzyme-Linked Immunosorbent Assay ; Gold Colloid ; Immunochromatography ; Membranes ; Porcine Reproductive and Respiratory Syndrome* ; Porcine respiratory and reproductive syndrome virus* ; Sensitivity and Specificity ; Staphylococcal Protein A ; Swine