Bovine TB: Research project summary
Project SE3028: The development of improved tests for the diagnosis of Mycobacterium bovis infection in cattle
Project duration: 3 years
The aim of this project was to improve and develop upon the tuberculin skin and IFN-y test which are current diagnostic tests used for the detection of Mycobacterium bovis (M. bovis) infection in cattle. This research has focused on the improvement of antigen cocktails which can 1) provide a specific and sensitive alternative to the tuberculin PPD antigens 2) differentiate between BCG vaccinated cattle and cattle infected with M. bovis. Using peptide technology and comparative genomics, the most immunogenic regions of frequently recognised proteins and specific epitopes were identified. These could be used to increase the sensitivity of antigenic cocktails.
The results derived that
1) the antigens Rv1986, Rv3873 and Rv3878 are good candidates for differential diagnosis
2) the proteins Rv1983, Rv1987 and Rv3879c are potential subunit vaccine candidates for boosting BCG-induced immunity and
3) for specific diagnosis the most potential immunodominant antigens are Rv3879c, Rv1987 and Rv1983.
In addition, the results determined that the addition of antigens to the prototype specific antigens ESAT-6, CFP-10 actually increased the sensitivity obtained. Furthermore, it has been determined that the method of using overlapping sets of peptides rather than recombinant protein, to undergo antigenicity screening, is an efficient approach to identify effective antigen cocktails. This study revealed that immune stimulation with peptides or recombinant proteins was equally effective. Overall, it was determined that the experimental approach of combining sequence homology analysis with experimental immunobiological evaluation is highly efficient in prioritising potential antigens to use in future diagnostic reagents. This work is continued under contract SE3222.
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Page last modified:
July 7, 2008