RESUMO
Preparation of a pure autoantigen by way of recombinant DNA technology has an important value in an accurate diagnosis or prognosis of an autoimmune disease. BCOADC-E2 subunit, a mitochondrial protein, has been known to be the autoantigen of primary biliary cirrhosis (PBC), a chronic autoimmune liver disease, as well as idiopathic dilated cardiomypathy (IDCM), a chronic autoimmune heart disease. Recombinant form of this molecule had been expressed in E. coli but with low yield and severe degradation. Furthermore, sera from IDCM patients failed to recognized BCOADC-E2 molecule produced in prokaryotic expression system. In this study, a recombinant bovine BCOADC-E2 fusion protein has been expressed in insect cells using baculovirus expression system and analyzed anti-BCOADC-E2 reactivity in sera from patients with PBC or with IDCM. Optimal production of the recombinant fusion protein has been achieved at 20 multiplicity of infection (MOI), and the protein was affinity-purified using metal-binding resins. The affinity-purified BCOADC-E2 protein was successfully recognized by sera from PBC patients, but not by sera from IDCM patients suggesting that the different auto-immune response against BCOADC-E2 is needed to be elucidated in terms of epitope recognition.
Assuntos
Bovinos , Humanos , Acetiltransferases/metabolismo , Acetiltransferases/imunologia , Acetiltransferases/genética , Animais , Baculoviridae/genética , Cardiomiopatia Dilatada/imunologia , Soros Imunes , Insetos/citologia , Cetona Oxirredutases/metabolismo , Cetona Oxirredutases/imunologia , Cetona Oxirredutases/genética , Cirrose Hepática Biliar/imunologia , Complexos Multienzimáticos/metabolismo , Complexos Multienzimáticos/imunologia , Complexos Multienzimáticos/genética , Engenharia de Proteínas/métodos , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/genéticaRESUMO
A mouse monoclonal antibody, Eh208C2-2 MAb, raised against whole cell antigens of Entamoeba histolytica trophozoites of the pathogenic strain HM-1: IMSS and polyclonal antisera (PAb) against membrane antigens of E. histolytica trophozoites of strain HTH-56: MUTM were screened against a cDNA library of the pathogenic strain, SFL3. The monoconal antibody detected many phage plaques expressing an E. histolytica protein. The DNA sequence encoding the protein was approximately 55% identical, over 1,100bp, to Trichomonas vaginalis pyruvate: ferredoxin oxidoreductase (PFOR) and pyruvate: flavodoxin oxidoreductase from Klebsiella pneumoniae, Anabaena variabilis and Enterobacter agglomerans. Two of seven clones detected by mouse polyclonal antisera also encoded this protein. Two others encoded Entamoeba Hsp70, another encoded Entamoeba alkyl-hydroperoxide reductase and the remaining two were unidentified sequences. Entamoeba PFOR is an abundant, antigenic protein which may be a useful target for the development of protective host immune responses against invasive amebiasis.