Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/18/2008
Publication Date: 4/18/2008
Citation: Barletta, R.G., Chacon, O., Fenton, R.J., Zinniel, D.K., Paulson, A.L., Kuszak, J.A., Mcvey, D.S., Smith, D.R., Bannantine, J.P. 2008. Roles of MAP1152 and MAP1156 Proteins in the Immunopathogenesis of Mycobacterium paratuberculosis [abstract]. Johne's Disease Integrated Program. p. 12. Interpretive Summary:
Technical Abstract: The Mycobacterium avium subsp. paratuberculosis (MAP) K-10 genome is a circular chromosome of about 4.8 Mb encoding 4,344 open reading frames (ORFs). Mycobacterial genomes are characterized by the presence of gene clusters encoding conserved proteins with PE and PPE motifs. Members of these families have been shown to display B- and T-cell immunoreactivity. We mapped an attenuated transposon mutant immediately upstream from a cluster of three PPE genes followed by an unrelated distal gene (MAP1152-MAP1156 region, 5638 bp). MAP1156 is a member of the uncharacterized protein family (UPF0089) that recent bioinformatic analysis attributes a potential role in lipid biosynthesis. Recombinant MAP1152 and MAP1156 were overproduced in E. coli as N-terminal fusion proteins to the 42 kDa maltose-binding protein. Western blot analysis demonstrated that both MAP1152 and MAP1156 were immunogenic in rabbits, while only MAP1156 was immunogenic in mice. MAP1152 displayed a low to moderate reactivity against serum from MAP-infected cattle diluted 1:200. In contrast, MAP1156 displayed high seroreactivity indicating that cattle elicit a strong humoral immunity against this protein. These results were confirmed by ELISA tests. We are currently screening diverse serum samples from cattle herds to determine the prevalence of this sero-reactivity. Likewise, we are developing T-cell assays to study the role of these proteins in cellular immunity. These results have implications for the development of sub-unit vaccines for the control of Johne's Disease.