In:
Infection and Immunity, American Society for Microbiology, Vol. 69, No. 1 ( 2001-01), p. 89-96
Abstract:
It is generally accepted that protective immunity against tuberculosis is generated through the cell-mediated immune (CMI) system, and a greater understanding of such responses is required if better vaccines and diagnostic tests are to be developed. γδ T cells form a major proportion of the peripheral blood mononuclear cells (PBMC) in the ruminant system and, considering data from other species, may have a significant role in CMI responses in bovine tuberculosis. This study compared the in vitro responses of αβ and γδ T cells from Mycobacterium bovis -infected and uninfected cattle. The results showed that, following 24 h of culture of PBMC with M. bovis -derived antigens, the majority of γδ T cells from infected animals became highly activated (upregulation of interleukin-2R), while a lower proportion of the αβ T-cell population showed activation. Similar responses were evident to a lesser degree in uninfected animals. Study of the kinetics of this response showed that γδ T cells remained significantly activated for at least 7 days in culture, while activation of αβ T cells declined during that period. Subsequent analysis revealed that the majority of activated γδ T cells expressed WC1, a 215-kDa surface molecule which is not expressed on human or murine γδ T cells. Furthermore, in comparison with what was found for CD4 + T cells, M. bovis antigen was found to induce strong cellular proliferation but relatively little gamma interferon release by purified WC1 + γδ T cells. Overall, while the role of these cells in protective immunity remains unclear, their highly activated status in response to M. bovis suggests an important role in antimycobacterial immunity, and the ability of γδ T cells to influence other immune cell functions remains to be elucidated, particularly in relation to CMI-based diagnostic tests.
Type of Medium:
Online Resource
ISSN:
0019-9567
,
1098-5522
DOI:
10.1128/IAI.69.1.89-96.2001
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2001
detail.hit.zdb_id:
1483247-1
