RESUMO
BACKGROUND: Nucleoprotein (NP) of influenza viruses is utilized to differentiate between the A, B, and C viral serotypes. The availability of influenza genome sequence data has allowed us to identify specific amino acids at particular positions in viral proteins, including NP, known as "signature residues," which can be used to discriminate human influenza A viruses from H5N1 highly pathogenic avian influenza in human cases (HPAI) and pandemic H1N1(2009) (H1N1/2009) viruses. METHODS: Screening and epitope mapping of monoclonal antibodies (mAb) against NP of influenza A, which reacted differently with NP from human influenza A virus from HPAI and H1N1/2009 A virus. To identify the epitope(s) responsible for the discrimination of viral NP by mAbs, we prepared mutant NP proteins in the 293 cell expression system because some of the mAbs reacted with non-linear epitopes. RESULTS AND CONCLUSIONS: In the present study, we identified 3 mAbs. The results of epitope mapping showed that the epitopes were located at the signature residues. These results indicated that signature residues of NP could discriminate influenza A viruses from different origin.
Assuntos
Aminoácidos/imunologia , Anticorpos Antivirais , Epitopos/imunologia , Vírus da Influenza A/classificação , Vírus da Influenza A/imunologia , Proteínas de Ligação a RNA/imunologia , Proteínas do Core Viral/imunologia , Virologia/métodos , Anticorpos Monoclonais , Humanos , Proteínas do NucleocapsídeoRESUMO
GPR40 is G protein-coupled receptor whose endogenous ligands have recently been identified as free fatty acids (FFAs), and it has been implicated to play an important role in FFA-mediated enhancement of glucose-stimulated insulin release. We have developed a monoclonal antibody against the extracellular domain of GPR40. Specificity of the antibody was demonstrated by immunoprecipitation and cell surface staining using GPR40-transfected cells. GPR40 immunoreactivity was highly abundant in mouse pancreatic beta-cells and splenocytes, THP-1 cells, and human peripheral blood mononuclear cells. The anti-GPR40 monoclonal antibody should prove valuable for further studying the function of this nutrient sensing receptor.
