Submitted to: American Association of Veterinary Laboratory Diagnosticians
Publication Type: Abstract Only
Publication Acceptance Date: 10/9/2003
Publication Date: 10/9/2003
Citation: Waters, W.R., Palmer, M.V., Whipple, D.L., Carlson, M.P., Nonnecke, B.J. 2003. Antigen-induced ifn-g, nitric oxide, and tnf-a production by blood mononuclear cells from mycobacterium bovis-infected cattle: diagnostic implications (abstract). American Association of Veterinary Laboratory Diagnosticians. p. 180.
Technical Abstract: Bovine tuberculosis in the United States has proven costly to cattle producers as well as government regulatory agencies. While in vivo responsiveness to mycobacterial antigens is the current standard for the diagnosis of tuberculosis, in vitro assays are gaining acceptance, especially as ancillary or complimentary tests. To evaluate in vitro indices of cellular sensitization, antigen induced interferon (IFN)-g, nitric oxide (NO), and tumor necrosis factor (TNF)-a responses by blood mononuclear cells from Mycobacterium bovis-infected cattle were quantified and compared. Using an aerosol model of infection, two doses each of two strains of M. bovis (95-1315 and HC-2045T) were used to induce a range of IFN-g, NO, and TNF-a responses. Infection specific increases in NO, but not IFN-g or TNF-a, were detected in nonstimulated cultures at 48h, indicative of nonspecific activation and spontaneous release of NO. The infective dose of M. bovis also influenced responses. At 34d postinfection, IFN-g, NO, and TNF-a responses in antigen-stimulated cells from cattle receiving 105 cfu M. bovis were greater than responses of cells from cattle infected with 103 cfu M. bovis. The NO response, but not IFN-g and TNF-a responses, was influenced by infective strain of M. bovis. TNF-a, NO, and IFN-g responses followed similar kinetics with strong positive associations between the three readouts. Overall, these findings indicate that NO and TNF-a, like IFN-g, may prove useful as indices for the diagnosis of bovine tuberculosis