Submitted to: Proteome Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/2008
Publication Date: 1/28/2008
Citation: Bannantine, J.P., Bayles, D.O., Waters, W.R., Palmer, M.V., Stabel, J.R., Paustian, M. 2008. Early Antibody Response Against Mycobacterium avium subspecies paratuberculosis Antigens in Subclinical Cattle. Proteome Science. 6:5.
Interpretive Summary: In this communication we further capitalized on our calf model of infection with M. paratuberculosis, the bacterium that causes Johne’s disease. We used four different test sera collected from each of two experimentally infected calves to identify which proteins are the most reactive with cattle antibodies. The proteins we used are produced by genetic engineering and represent 92 M. paratuberculosis proteins. We discovered one of these proteins (MAP1087) was not only reactive at the earliest time point after infection, but was also the strongest reactive protein among the set of 92. When this protein was used to check NADC cattle in the early “subclinical” stage of infection, it was found to be reactive in 5 of the 9 naturally infected animals. These findings may have a strong influence on the early detection of Johne’s disease in cattle.
Technical Abstract: Abstract Background Our laboratories have previously reported on the experimental infection of cattle with Mycobacterium avium subsp paratuberculosis (M. paratuberculosis) using an intratonsillar infection model. In addition, we have recently developed a partial protein array representing 92 M. paratuberculosis coding sequences. These combined tools have enabled a unique look at the temporal analysis of M. paratuberculosis antigens within the native host. The primary objective of this study was to identify M. paratuberculosis antigens detected by cattle early during infection. A secondary objective was to evaluate the humoral immune response in cattle during the initial year of infection. Results Sera from two experimentally infected cattle, taken pre-inoculation and at day 70, 194 and 321 post infection, identified dynamic antibody reactivity among antigens with some showing an increased response over time and others showing declining levels of reactivity over the same time period. A M. paratuberculosis specific protein, encoded by MAP0862, was strongly detected initially, but the antibody response became weaker with time. The most reactive protein was a putative surface antigen encoded by MAP1087. A second protein, MAP1204, implicated in virulence, was also strongly detected by day 70 in both cattle. Subsequent experiments showed that these two proteins were detected with sera from 5 of 9 naturally infected cattle in the subclinical stage of Johne’s disease. Conclusions Collectively these results demonstrate that M. paratuberculosis proteins are detected by sera from experimentally infected cattle as early as 70 days after exposure. These data further suggest at least two antigens may be useful in the early diagnosis of M. paratuberculosis infections. Finally the construction and use of a protein array has led to the novel approach for discovery of M. paratuberculosis antigens.