ABSTRACT
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.
Subject(s)
Antibodies , Collodion , Colloids , Diagnostic Tests, Routine , Enzyme-Linked Immunosorbent Assay , Gold Colloid , Chromatography, Affinity , Membranes , Porcine Reproductive and Respiratory Syndrome , Porcine respiratory and reproductive syndrome virus , Sensitivity and Specificity , Staphylococcal Protein A , SwineABSTRACT
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.
ABSTRACT
Microfold (M) cells act as antigen-sampling sites for initiating antigen specific mucosal immune responses, but they may also provide a gateway for enteropathogen entry. In this study we demonstrated villous M cells by morphological and immunohistochemical methods to be present in the three regions of the small intestine from newborn piglets. Immunohistochemical analysis, using anti- cytokeratin 18 (CK18) primary antibodies, showed a gradually decreased density of M cells from the lower crypt epithelium to the upper villous epithelium. The proportion of villous M cells was greater in the ileum than in the duodenum or the mid-jejunum. Ultrastructural observation revealed that villous M cells were mainly columnar in shape in the duodenum and the mid-jejunum, and appeared as more pocket-like structure in the ileum. These villous M cells exhibited short and irregular microvilli, rich vesicles and reduced glycocalyx, but lacked the lymphocyte-containing basolateral invagination. Our results support evidence that M cells can develop in the small intestinal villous epithelium of newborn piglets, implying that villous M cells may begin developing in the pig's small intestine during fetal stages, which depends neither on the influence of the mucosal lymphoid tissue nor the antigen from the intestinal lumen stimulation. In addition, the variable morphology and heterogeneity distribution of villous M cells in the three regions of the small intestine may be indicative of its different functional properties. This information extent our understanding of the diversity of M cells and provides important basic knowledge for further research on the actual role of villous M cells in neonate.
Los epiteliocitos microplegados (células M) actúan como receptores de antígeno para iniciar la respuesta inmune específica de las mucosas, pero también pueden proporcionar una puerta de entrada para enteropatógenos. En este estudio, se demostró por métodos morfológicos e inmunohistoquímicos que los epiteliocitos microplegados de las vellosidades están presentes en las tres regiones del intestino delgado de lechones recién nacidos. Se utilizaron anticuerpos primarios de citoqueratina 18 (CK18) para el análisis inmunohistoquímico, el cual mostró una disminución gradual de la densidad de los epiteliocitos microplegados desde el epitelio de las criptas inferiores hasta el epitelio de las vellosidades superiores. La proporción de los epiteliocitos microplegados, fue mayor en el íleon que el duodeno o yeyuno medio. La observación ultraestructural reveló que los epiteliocitos microplegados fueron principalmente de forma columnar en el duodeno y el yeyuno medio. Además, mostraron microvellosidades cortas e irregulares, muchas vesículas y glucocáliz reducidos, pero carecían de invaginaciones basolaterales contenedoras de linfocitos. Nuestros resultados apoyan la evidencia de que los epiteliocitos microplegados pueden desarrollarse en el epitelio de las vellosidades intestinales de los lechones recién nacidos, lo que implica que estas células pueden comenzar a desarrollarse en el intestino delgado del cerdo durante las etapas fetales, y no dependen ni de la influencia del tejido linfoide de las mucosas ni del antígeno para la estimulación del lumen intestinal. Además, la morfología y heterogeneidad de distribución de los epiteliocitos microplegados en las tres regiones del intestino delgado pueden ser indicativas de sus diferentes propiedades funcionales. Esta información mejora nuestra comprensión de la diversidad de los epiteliocitos microplegados y proporciona conocimientos básicos importantes para la investigación sobre el papel de los epiteliocitos microplegados en las vellosidades del neonato.