|Slaughter, R - BIOCOR ANIMAL HEALTH|
|Jones, S - CSL ANIMAL HEALTH|
Submitted to: Journal of Wildlife Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 3, 2003
Publication Date: January 1, 2004
Citation: Waters, W.R., Palmer, M.V., Whipple, D.L., Slaughter, R.E., Jones, S.L. 2004. Immune responses of white-tailed deer (odocoileus virginianus) to mycobacterium bovis bcg vaccination. Journal of Wildlife Diseases. 40:66-78. Interpretive Summary: White-tailed deer are wildlife reservoirs of bovine tuberculosis within the United States. The presence of this reservoir host seriously hinders 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. Presently, a live tuberculosis vaccine was used to evoke an immune response by deer and the diagnostic ramifications of these responses were determined. Findings from this study will be useful for defining improved protocols for detection of tuberculous deer within captive herds.
Technical Abstract: The objective was to evaluate the cellular immune response of captive white-tailed deer (Odocoileus virginianus) to live Mycobacterium bovis bacille Calmette Guerin (BCG) vaccination and to determine diagnostic implications of these responses. In vitro proliferative and interferon-g (IFN-g) responses to M. bovis purified protein derivative (PPD) were detected beginning 9 days postvaccination. Responses to M. avium PPD, however, generally exceeded responses to M. bovis PPD. IFN-g responses to M. avium PPD were not detected prior to vaccination nor in non-vaccinated deer, suggesting that vaccination with BCG boosted prior quiescent M. avium sensitized cells. Both CD4**+ and gamma delta T cells from vaccinated deer proliferated in response to M. bovis PPD stimulation. Intradermal administration of M. bovis PPD resulted in increases in skin thickness of vaccinated deer beginning 24 hrs postinjection. Such early reactions were characterized by edema and minimal mononuclear cell infiltration whereas later reactions (i.e., 72 hrs postinjection) were more typical of delayed type hypersensitivity. Upon in vitro activation with pokeweed mitogen, CD44 expression increased and CD62L expression decreased on lymphocytes from deer regardless of vaccination status. Likewise, M. bovis PPD stimulation of lymphocytes from vaccinated deer resulted in increases in CD44 expression and decreases in CD62L expression. In summary, these findings demonstrate the potential of BCG vaccination to elicit strong cell-mediated immune responses and appropriate alterations in CD44 and CD62L expression upon in vitro stimulation of white-tailed deer lymphocytes. Transient weak IFN-g responses to BCG vaccination, unlike skin test reactions, will likely not interfere with tuberculosis testing.