Submitted to: Journal of Wildlife Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2001
Publication Date: N/A
Interpretive Summary: White-tailed deer are wildlife reservoirs of bovine tuberculosis within the United States. The presence of this reservoir host seriously threatens ongoing efforts to eradicate this disease from cattle. Control measures alternative to abattoir surveillance or test and slaughter campaigns are being considered for control in other developed countries with wildlife reservoirs of bovine tuberculosis. Considering this trend, it is of importance to determine host responses to tuberculosis within the reservoir host as a means to develop improved control methods. A potent mechanism of killing the tuberculosis agent, at least in mice and humans, is via generation of nitrite by white blood cells. In the present study, it was determined that white blood cells from white-tailed deer are also capable of generating nitrite in response to stimulation with the tuberculosis agent. These findings will be useful for the development of improved methods of bovine tuberculosis control.
Technical Abstract: White-tailed deer (Odocoileus virginianus) are reservoirs for Mycobacterium bovis infection of domestic cattle (Bos taurus) within the United States. Production of nitric oxide (NO) by activated macrophages is a potent mechanism of mycobacterial killing. The capacity of macrophages to produce NO, however, varies between mammalian species. The objective of this study was to determine if mononuclear cells from white-tailed deer produce nitrite (e.g., indicative of NO production) and, if so, is it produced in response to stimulation with M. bovis antigens. Nitrite within adherent peripheral blood mononuclear cell (PBMC) culture supernatants stimulated with Pasteurella multocida lipopolysaccharide (LPS) exceeded (p < 0.05) that detected within non-stimulated cultures and cultures stimulated with P. multocida LPS and an inhibitor of nitric oxide synthase. Nitrite production by PBMC isolated from M. bovis-infected deer in response to stimulation with M. bovis antigens exceeded (p < 0.05) that of the response to no stimulation and the response by non-infected deer to stimulation with M. bovis antigens. The response of M. bovis-infected deer to M. avium antigens did not differ from their response to no stimulation or from the response of non-infected deer to M. avium antigens. These findings indicate that adherent PBMC from white-tailed deer are capable of NO production and that mononuclear cells isolated from M. bovis-infected white-tailed deer produce NO in an antigen-specific recall response.