Exploiting the Campylobacter jejuni protein glycosylation system for glycoengineering vaccines and diagnostic tools directed against brucellosis
1 Alberta Glycomics Centre, Department of Biological Sciences, University of Alberta, Edmonton, AB, TG6 2E9, Canada
2 Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada
3 Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, T6G 2H7, Canada
4 Instituto de Investigaciones Biotecnológicas, "Dr. Rodolfo A. Ugalde", IIB-INTECH, CONICET, Universidad Nacional de San Martín, Av. Gral. Paz 5445, PREDIO INTI, Edificio 24 (1650), Buenos Aires, Argentina
5 Pathogen Molecular Biology Unit, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
6 GlycoVaxyn AG, Grabenstrasse 3, 8952 Schlieren, Switzerland
7 Department of Biological Sciences, CW 405, Biological Sciences Bldg, University of Alberta, Edmonton, T6G 2E9, Canada
Microbial Cell Factories 2012, 11:13 doi:10.1186/1475-2859-11-13Published: 25 January 2012
Immune responses directed towards surface polysaccharides conjugated to proteins are effective in preventing colonization and infection of bacterial pathogens. Presently, the production of these conjugate vaccines requires intricate synthetic chemistry for obtaining, activating, and attaching the polysaccharides to protein carriers. Glycoproteins generated by engineering bacterial glycosylation machineries have been proposed to be a viable alternative to traditional conjugation methods.
In this work we expressed the C. jejuni oligosaccharyltansferase (OTase) PglB, responsible for N-linked protein glycosylation together with a suitable acceptor protein (AcrA) in Yersinia enterocolitica O9 cells. MS analysis of the acceptor protein demonstrated the transfer of a polymer of N-formylperosamine to AcrA in vivo. Because Y. enterocolitica O9 and Brucella abortus share an identical O polysaccharide structure, we explored the application of the resulting glycoprotein in vaccinology and diagnostics of brucellosis, one of the most common zoonotic diseases with over half a million new cases annually. Injection of the glycoprotein into mice generated an IgG response that recognized the O antigen of Brucella, although this response was not protective against a challenge with a virulent B. abortus strain. The recombinant glycoprotein coated onto magnetic beads was efficient in differentiating between naïve and infected bovine sera.
Bacterial engineered glycoproteins show promising applications for the development on an array of diagnostics and immunoprotective opportunities in the future.