|Gurung, Ratna -|
|Begg, Douglas -|
|Purdie, Auriol -|
|DE Silva, Kumudika -|
|Whittington, Richard -|
Submitted to: Clinical and Vaccine Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 28, 2014
Publication Date: June 1, 2014
Repository URL: http://handle.nal.usda.gov/10113/58874
Citation: Gurung, R.B., Begg, D.J., Purdie, A.C., De Silva, K., Bannantine, J.P., Whittington, R.J. 2014. Lymphoproliferative and gamma interferon responses to stress-regulated Mycobacterium avium subsp. paratuberculosis recombinant proteins. Clinical and Vaccine Immunology. 21(6):831-837. Interpretive Summary: Johne’s disease in livestock such as dairy cattle and sheep is caused by the bacterium Mycobacterium avium subspecies paratuberculosis (MAP). A major obstacle to controlling this disease is early detection after infection and before the animal begins shedding the bacterium on the farm and thus providing a source for infecting herd mates. In this manuscript, we examined the ability of MAP recombinant proteins to stimulate a host immune marker, which is the earliest detected following infection with MAP. This immune marker is termed gamma interferon (IFN-g). Of the ten recombinant proteins analyzed, four showed some degree of IFN-g stimulation. These four proteins are worth a further examination for early diagnosis of Johne’s disease. This research is of primary interest to veterinarians, stakeholders and other researchers in the field.
Technical Abstract: Johne’s disease in ruminants is a chronic infection of the intestines caused by Mycobacterium avium subsp. paratuberculosis. Economic losses associated with Johne’s disease arise due to premature culling, reduced production of milk and wool and mortalities. The disease is characterised by a long incubation period and subclinical infection creates a potential source of infection for unexposed animals. An important strategy in the management and control of Johne’s disease is the early detection and culling of infected animals. A potentially efficient method for detecting early infection is by measuring cell mediated immune responses developed by the host in response to exposure or infection. One method is to measure lymphoproliferation and cytokine release from the host cells when exposed to the organism or parts of the organism. In this study, 10 recombinant antigens prepared from stress-regulated proteins were evaluated by examining their ability to evoke memory as a result of exposure by vaccination or oral challenge with live organisms. Four of these antigens, MAP2698c, MAP1589c, MAP3567 and MAP1560, were found to induce higher lymphoproliferation and IFN-gamma responses in vaccinated and challenged sheep in comparison to healthy controls. These antigens may be of potential use in detecting early immune responses due to exposure to Mycobacterium avium subsp. paratuberculosis in sheep.