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Brucella abortus induces intracellular retention of MHC-I molecules in human macrophages down-modulating cytotoxic CD8(+) T cell responses.
- Source :
-
Cellular microbiology [Cell Microbiol] 2013 Apr; Vol. 15 (4), pp. 487-502. Date of Electronic Publication: 2012 Nov 21. - Publication Year :
- 2013
-
Abstract
- Brucella abortus elicits a vigorous Th1 immune response which activates cytotoxic T lymphocytes. However, B. abortus persists in its hosts in the presence of CD8(+) T cells, establishing a chronic infection. Here, we report that B. abortus infection of human monocytes/macrophages inhibited the IFN-γ-induced MHC-I cell surface expression. This phenomenon was dependent on metabolically active viable bacteria. MHC-I down-modulation correlated with the development of diminished CD8(+) cytotoxic T cell response as evidenced by the reduced expression of the activation marker CD107a on CD8(+) T lymphocytes and a diminished percentage of IFN-γ-producing CD8(+) T cells. Inhibition of MHC-I expression was not due to changes in protein synthesis. Rather, we observed that upon B. abortus infection MHC-I molecules were retained within the Golgi apparatus. Overall, these results describe a novel mechanism based on the intracellular sequestration of MHC-I molecules whereby B. abortus would avoid CD8(+) cytotoxic T cell responses, evading their immunological surveillance.<br /> (© 2012 Blackwell Publishing Ltd.)
- Subjects :
- Cells, Cultured
Golgi Apparatus chemistry
Humans
Interferon-gamma metabolism
Protein Transport
Brucella abortus immunology
Brucella abortus physiology
CD8-Positive T-Lymphocytes immunology
Histocompatibility Antigens Class I metabolism
Immune Evasion
Macrophages immunology
Macrophages microbiology
Subjects
Details
- Language :
- English
- ISSN :
- 1462-5822
- Volume :
- 15
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Cellular microbiology
- Publication Type :
- Academic Journal
- Accession number :
- 23107169
- Full Text :
- https://doi.org/10.1111/cmi.12058