Production of < b > < i > Mycobacterium bovis < /i > < /b > Antigens Included in Recombinant Occlusion Bodies of Baculovirus

Bovine tuberculosis (bTB) is a disease produced byMycobacterium bovis that affects livestock, wild animals, and humans. The classical diagnostic method to detect bTB is measuring the response induced with the intradermal injection of purified protein derivative ofM. bovis (PPDb). Another ancillary bTB test detects IFN- γ produced in whole blood upon stimulation with PPDb, protein/peptide cocktails, or individual antigens. Among the most usedM. bovis antigens in IFN- γ assays are the secreted proteins ESAT-6 and CFP-10, which together with antigen Rv3615c improve the sensitivity of the test in comparison to PPDb. Protein reagents for immune stimulation are generally obtained fromEscherichia coli, because this bacterium produces a high level of recombinant proteins. However,E. coli recombinant antigens are in general contaminated with lipopolysaccharides and other components that produce non-specific IFN- γ secretion in in vitro assays. In this work, we produced the relevant ESAT-6, CFP-10, and Rv3615cM. bovis antigens as fusions to the polyhedrin protein from the baculovirus AcMNPV. We obtained chimeric proteins effectively incorporated to the occlusion bodies and easily purified the recombinant polyhedra with no reactive contaminants. In an IFN- γ assay, these fusion proteins showed equivalent sensibility but better specificity than the sameM. bovis proteins produced inE. coli.J Mol Microbiol Biotechnol
Source: Journal of Molecular Microbiology and Biotechnology - Category: Microbiology Source Type: research