Newcastle disease (ND) caused by virulent Newcastle disease virus (NDV) is a highly contagious viral disease of poultry. Virulent NDVs characteristically have a multibasic amino acid sequence (virulence motif) such as (112)RRQKRF(117) at the cleavage site of the precusor fusion (F0) protein. The antigenic and immunogenic characteristics of the virulence motif (112)RRQKRF(117) in the F0 protein of virulent NDVs were investigated. Epitope mapping analysis revealed that a RRQKRF-specific monoclonal antibody 4G2 recognized the KRF section of the motif. A synthetic peptide bearing the RRQKRF motif reacted strongly with sera from virulent NDV (with RRQKRF motif)-infected chickens. These sera also showed reactivity to peptides bearing other virulence motifs ((112)KRQKRF(117), (112)RRQRRF(117) and (112)RRRKRF(117)) but not an avirulence motif ((112)GRQGRL(117)) by ELISA. The synthetic bearing RRQKRF motif reacted with 60% to 91% of sera taken from surviving chickens on ND outbreak farms but not with sera from vaccinated birds, even though most of the sera had antibody to NDV due to vaccination. This indicates that the virulence motif has the potential to differentiate virulent NDV infected birds from vaccinated birds.
Amino Acid Motifs/*immunology ; Amino Acid Sequence ; Animals ; Chickens ; Enzyme-Linked Immunosorbent Assay/veterinary ; Epitope Mapping/veterinary ; Newcastle Disease/*immunology ; Newcastle disease virus/*genetics/pathogenicity ; Poultry Diseases/*immunology/*virology ; Serologic Tests/veterinary ; Viral Fusion Proteins/*genetics/immunology ; Virulence/genetics

OBJECTIVETo develop a novel vaccine by immobilizing interleukin-21 (IL-21) on the surface of MB49 cells and evaluate its effect in inducing specific cytotoxic T lymphocytes (CTLs) and antitumor immunity in a mouse model of subcutaneous metastatic bladder cancer.

METHODSSA-IL-21 was immobilized on the surface of 30% ethanol-fixed MB49 cells to prepare the cell vaccine. C57BL/6 mice with subcutaneous implantation of MB49 bladder cancer cells were randomized into 5 groups to receive treatments with IL-21/MB49 vaccine, soluble IL-21, GFP surface-modified MB49 cells, ethanol-fixed MB49 cells, or PBS. The tumor growth and CTL were examined to assess the antitumor efficacy of the vaccine.

RESULTSIL-21 surface-modified MB49 cell vaccine significantly inhibited the tumor growth and generated a long-lasting memory response (P<0.05). At the same effector-target (E:T) ratio, the specific CTLs induced by IL-21/MB49 vaccine showed the most potent cytotoxicity against MB49 cells (P<0.05).

CONCLUSIONWith the protein-anchor technique, IL-21 can be efficiently immobilized on the surface of MB49 cells to prepare IL-21/MB49 cells vaccine. The novel vaccine can maintain its biological activity and significantly enhance the cytotoxicity of CTLs against bladder cancer cells.

Amino Acid Motifs ; Animals ; Cancer Vaccines ; therapeutic use ; Cell Line, Tumor ; Female ; Immunotherapy ; Interleukins ; immunology ; Lymphocyte Activation ; Mice ; Mice, Inbred C57BL ; Neoplasm Metastasis ; Neoplasms, Experimental ; therapy ; T-Lymphocytes, Cytotoxic ; immunology ; Urinary Bladder Neoplasms ; therapy

The Coronaviridae family is characterized by a nucleocapsid that is composed of the genome RNA molecule in combination with the nucleoprotein (N protein) within a virion. The most striking physiochemical feature of the N protein of SARS-CoV is that it is a typical basic protein with a high predicted pI and high hydrophilicity, which is consistent with its function of binding to the ribophosphate backbone of the RNA molecule. The predicted high extent of phosphorylation of the N protein on multiple candidate phosphorylation sites demonstrates that it would be related to important functions, such as RNA-binding and localization to the nucleolus of host cells. Subsequent study shows that there is an SR-rich region in the N protein and this region might be involved in the protein-protein interaction. The abundant antigenic sites predicted in the N protein, as well as experimental evidence with synthesized polypeptides, indicate that the N protein is one of the major antigens of the SARS-CoV. Compared with other viral structural proteins, the low variation rate of the N protein with regards to its size suggests its importance to the survival of the virus.
Amino Acid Motifs ; genetics ; Amino Acid Sequence ; Antigens, Viral ; immunology ; Base Composition ; Base Sequence ; Cluster Analysis ; Computational Biology ; DNA Primers ; Enzyme-Linked Immunosorbent Assay ; Genetic Variation ; Molecular Sequence Data ; Nucleocapsid Proteins ; genetics ; immunology ; metabolism ; Phosphorylation ; SARS Virus ; genetics ; Sequence Analysis, DNA

Betaig-h3 (betaig-h3) is a secretory protein composed of fasciclin I-like repeats containing sequences that allows binding of integrins and glycosaminoglycans in vivo. Expression of betaig-h3 is responsive to TGF-beta and the protein is found to be associated with extracellular matrix (ECM) molecules, implicating betaig-h3 as an ECM adhesive protein of developmental processes. We previously observed predominant expression of betaig-h3 expression in the basement membrane of proximal tubules of kidney. In this study, the physiological relevance of such localized expression of betaig-h3 was examined in the renal proximal tubular epithelial cells (RPTEC). RPTEC constitutively expressed betaig-h3 and the expression was dramatically induced by exogenous TGF-beta1 treatment. betaig-h3 and its second and fourth FAS1 domain were able to mediate RPTEC adhesion, spreading and migration. Two known alpha3beta1 integrin-interaction motifs including aspartatic acid and isoleucine residues, NKDIL and EPDIM in betaig-h3 were responsible to mediate RPTEC adhesion, spreading, and migration. By using specific antibodies against integrins, we confirmed that alpha3beta1 integrin mediates the adhesion and migration of RPTECs on betaig-h3. In addition, it also enhanced proliferation of RPTECs through NKDIL and EPDIM. These results indicate that betaig-h3 mediates adhesion, spreading, migration and proliferation of RPTECs through the interaction with alpha3beta1 integrin and is intimately involved in the maintenance and the regeneration of renal proximal tubular epithelium.
Amino Acid Motifs ; Antibodies, Blocking/immunology ; Cell Adhesion/physiology ; Cell Movement/physiology ; Cell Proliferation ; Cells, Cultured ; Epithelial Cells/drug effects ; Extracellular Matrix Proteins/chemistry/immunology/*metabolism ; Humans ; Integrin alpha3beta1/chemistry/immunology/*metabolism ; Kidney Tubules, Proximal/cytology/metabolism/*physiology ; Peptides/chemistry/metabolism ; Protein Interaction Mapping ; Research Support, Non-U.S. Gov't ; Transforming Growth Factor beta/chemistry/immunology/*metabolism/pharmacology

Entero virus 71 (EV71) causes hand, foot, and mouth disease (HFMD) and occasionally leads to severe neurological complications and even death. Scavenger receptor class B member 2 (SCARB2) is a functional receptor for EV71, that mediates viral attachment, internalization, and uncoating. However, the exact binding site of EV71 on SCARB2 is unknown. In this study, we generated a monoclonal antibody (mAb) that binds to human but not mouse SCARB2. It is named JL2, and it can effectively inhibit EV71 infection of target cells. Using a set of chimeras of human and mouse SCARB2, we identified that the region containing residues 77-113 of human SCARB2 contributes significantly to JL2 binding. The structure of the SCARB2-JL2 complex revealed that JL2 binds to the apical region of SCARB2 involving α-helices 2, 5, and 14. Our results provide new insights into the potential binding sites for EV71 on SCARB2 and the molecular mechanism of EV71 entry.
Amino Acid Sequence ; Animals ; Antibodies, Monoclonal ; chemistry ; genetics ; metabolism ; Binding Sites ; Cell Line ; Crystallography, X-Ray ; Enterovirus A, Human ; drug effects ; genetics ; growth & development ; immunology ; Fibroblasts ; drug effects ; virology ; Gene Expression ; HEK293 Cells ; Humans ; Immunoglobulin Fab Fragments ; chemistry ; genetics ; metabolism ; Lysosome-Associated Membrane Glycoproteins ; chemistry ; genetics ; immunology ; Mice ; Models, Molecular ; Protein Binding ; Protein Conformation, alpha-Helical ; Protein Conformation, beta-Strand ; Protein Interaction Domains and Motifs ; Receptors, Scavenger ; chemistry ; genetics ; immunology ; Receptors, Virus ; chemistry ; genetics ; immunology ; Recombinant Fusion Proteins ; chemistry ; genetics ; immunology ; Sequence Alignment ; Sequence Homology, Amino Acid ; Sf9 Cells ; Spodoptera ; Thermodynamics