CD4+ Alpha Beta T Cell And Gamma Delta T Cell Responses To Mycobacterium Tuberculosis. Similarities And Differences In Ag Recognition, Cytotoxic Effector Function, And Cytokine Production.

Content Provider	Indian Institute of Science (IISc)
Author	Tsukaguchi, K. Balaji, K. N. Boom, W. H.
Copyright Year	1995
Abstract	CD4+ and gamma delta T cells are activated readily by Mycobacterium tuberculosis. To examine their role in the human immune response to M. tuberculosis, CD4+ and gamma delta T cells from healthy tuberculin-positive donor were studied for patterns of Ag recognition, cytotoxicity, and cytokine production in response to M. tuberculosis-infected mononuclear phagocytes. Both T cell subsets responded to intact M. tuberculosis and its cytosolic Ags. However, CD4+ and gamma delta T cells differed in the range of cytosolic Ags recognized: reactivity to a wide m.w. range of Ags for CD4+ T cells, and a restricted pattern for gamma delta T cells, with dominance of Ags of 10 to 15 kDa. Both T cell subsets were equally cytotoxic for M. tuberculosis-infected monocytes. Furthermore, both CD4+ and gamma delta T cells produced large amounts of IFN-gamma: mean pg ml of IFN-gamma in supernatants was 2458 + - 213 for CD4+ and 2349 + - 245 for gamma delta T cells. By filter-spot ELISA (ELISPOT), the frequency of IFN-gamma-secreting gamma delta T cells was one-half of that of CD4+ T cells in response to M. tuberculosis, suggesting that gamma delta T cells on a per cell basis were more efficient producers of IFN-gamma than CD4+ T cells. In contrast, CD4+ T cells produced more IL-2 than gamma delta T cells, which correlated with diminished T cell proliferation of gamma delta T cells compared with CD4+ T cells. These results indicate that CD4+ and gamma delta T cell subsets have similar effector functions (cytotoxicity, IFN-gamma production) in response to M. tuberculosis-infected macrophages, despite differences in the Ags recognized, IL-2 production, and efficiency of IFN-gamma production.
File Format	PDF
Journal	PeerReviewed
Language	English
Publisher	American Association of Immunologists
Publisher Date	1995-02-15
Access Restriction	Authorized
Subject Keyword	Microbiology & Cell Biology
Content Type	Text
Resource Type	Article