Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/25/2007
Publication Date: 3/1/2008
Publication URL: www.sciencedirect.com
Citation: Bannantine, J.P., Rosu, V., Zanetti, S., Rocca, S., Ahmed, N., Sechi, L.A. 2008. Antigenic Profiles of Recombinant Proteins from Mycobacterium avium subsp. paratuberculosis in Sheep with Johne's Disease. Veterinary Immunology and Immunopathology. 122(1-2):116-125. Interpretive Summary: Dozens of purified recombinant proteins have been constructed in the bacterium Escherichia coli. The recombinant proteins represent proteins produced by Mycobacterium avium subsp paratuberculosis, the bacterium that causes Johne’s disease in sheep, dairy cattle and other ruminant animals. We evaluated 18 recombinant proteins as possible antigens that sheep with Johne’s disease. Furthermore, we examined specificity of these proteins by including 10 healthy, control sheep in our experiments. We found that no single protein was the perfect antigen that was detected by all the infected sheep and not detected by all the healthy sheep, but some of the proteins do look promising in further studies. This work is of most value to researchers in the field and may be of interest to animal producers.
Technical Abstract: Methods to improve the ELISA test to detect Mycobacterium avium subsp paratuberculosis have been explored over several years. Previously, selected recombinant proteins of M. avium subspecies paratuberculosis were found to be immunogenic in cattle with Johne’s disease. In the present study, antibody responses of infected and healthy sheep were evaluated using 18 purified recombinant proteins in an ELISA-based format for the serodiagnosis of ovine paratuberculosis. These selected recombinant proteins represent heat shock proteins, hypothetical proteins and cell surface proteins of M. avium subsp paratuberculosis. Whereas, MAP0862 (a gene uniquely present in M. avium subspecies paratuberculosis) and MAP3786 encoded protein solicited the strongest antibody response in infected sheep. The protein encoded by MAP2116c showed the weakest antibody response among the animals tested. Although none of the recombinant proteins detected all eleven infected sheep singly, antibodies to MAP0862 were detected in 9 of 11 (81%) infected sheep. Furthermore, ovine responses to these selected antigens were assessed temporally over the course of one year during which we found a spiking effect rather than an incremental increase of antibody reactivity. This study evaluated multiple M. avium subsp paratuberculosis recombinant proteins in an ELISA-based format for sheep.