title: Display of Antigens on Polyester Inclusions Lowers the Antigen Concentration Required for a Bovine Tuberculosis Skin Test.
abstract: The tuberculin skin test is the primary screening test for the diagnosis of bovine tuberculosis (TB), and use of this test has been very valuable in the control of this disease in many countries. However, the test lacks specificity when cattle have been exposed to environmental mycobacteria or vaccinated with Mycobacterium bovis bacille Calmette-Guérin (BCG). Recent studies showed that the use of three or four recombinant mycobacterial proteins, including 6-kDa early secretory antigenic target (ESAT6), 10-kDa culture filtrate protein (CFP10), Rv3615c, and Rv3020c, or a peptide cocktail derived from those proteins, in the skin test greatly enhanced test specificity, with minimal loss of test sensitivity. The proteins are present in members of the pathogenic Mycobacterium tuberculosis complex but are absent in or not expressed by the majority of environmental mycobacteria and the BCG vaccine strain. To produce a low-cost skin test reagent, the proteins were displayed at high density on polyester beads through translational fusion to a polyhydroxyalkanoate synthase that mediates the formation of antigen-displaying inclusions in recombinant Escherichia coli. Display of the proteins on the polyester beads greatly increased their immunogenicity, allowing for the use of very low concentrations of proteins (0.1 to 3 μg of mycobacterial protein/inoculum) in the skin test. Polyester beads simultaneously displaying all four proteins were produced in a single fermentation process. The polyester beads displaying three or four mycobacterial proteins were shown to have high sensitivity for detection of M. bovis-infected cattle and induced minimal responses in animals exposed to environmental mycobacteria or vaccinated with BCG.
authors.affiliation: AgResearch, Hopkirk Research Institute, Palmerston North, New Zealand.
authors.forename: Natalie A
authors.initials: NA
authors.lastname: Parlane
authors.affiliation: Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand.
authors.forename: Shuxiong
authors.initials: S
authors.lastname: Chen
authors.affiliation: TB Immunology and Vaccinology, Animal and Plant Health Agency, New Haw, Addlestone, Surrey, United Kingdom.
authors.forename: Gareth J
authors.initials: GJ
authors.lastname: Jones
authors.affiliation: TB Immunology and Vaccinology, Animal and Plant Health Agency, New Haw, Addlestone, Surrey, United Kingdom.
authors.forename: H Martin
authors.initials: HM
authors.lastname: Vordermeier
authors.affiliation: AgResearch, Hopkirk Research Institute, Palmerston North, New Zealand.
authors.forename: D Neil
authors.initials: DN
authors.lastname: Wedlock
authors.affiliation: Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand MacDiarmid Institute for Advanced Materials and Nanotechnology, Palmerston North, New Zealand Polybatics Ltd., Palmerston North, New Zealand.
authors.forename: Bernd H A
authors.initials: BH
authors.lastname: Rehm
authors.affiliation: AgResearch, Hopkirk Research Institute, Palmerston North, New Zealand bryce.buddle@agresearch.co.nz.
authors.forename: Bryce M
authors.initials: BM
authors.lastname: Buddle
mesh_terms: D000217:Acyltransferases / Q000235:genetics; D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D001500:BCG Vaccine / Q000276:immunology; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology*; D002417:Cattle; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology; D007371:Interferon-gamma; D008863:Microspheres; D009163:Mycobacterium bovis / Q000737:chemistry / Q000276:immunology*; D011091:Polyesters / Q000737:chemistry*; D011994:Recombinant Proteins / Q000276:immunology; D012680:Sensitivity and Specificity; D014374:Tuberculin Test / Q000592:standards*; D014380:Tuberculosis, Bovine / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology
chemical_list: D000942:Antigens, Bacterial; D001500:BCG Vaccine; D001426:Bacterial Proteins; D011091:Polyesters; D011994:Recombinant Proteins; D007371:Interferon-gamma; D000217:Acyltransferases; C077225:poly(3-hydroxyalkanoic acid) synthase