INVESTIGADORES
POZNER Roberto Gabriel
congresos y reuniones científicas
Título:
Brucella RNA mimics the inhibition of major histocompatibility complex class I (MHC-I) expression mediated by Brucella abortus on human monocytes.
Autor/es:
MILILLO, M.; VELAZQUEZ, LIZ N.; DELPINO, MARIA V.; POZNER, ROBERTO G.; GIAMBARTOLOMEI, GUILLERMO H.; BARRIONUEVO, PAULA
Lugar:
Waterville Valley
Reunión:
Conferencia; 2015 Phagocytes Gordon Conference; 2015
Institución organizadora:
Gordon Conference
Resumen:
Brucella abortus is an intracellular Gram-negative bacterium that infects wild and domestic animals and can be transmitted to humans. Upon infection, Brucella elicits a vigorous Th1 immune response which activates cytotoxic T lymphocytes. However, B. abortus is able to persist inside its host and establishes a chronic infection. We recently reported that infection of human monocytes/macrophages with B. abortus inhibits the IFN-γ-induced MHC-I cell surface expression down-modulating cytotoxic CD8+ T cell responses. MHC-I down-modulation depends on bacterial viability and results from the capacity of B. abortus to retain the MHC-I molecules within the Golgi apparatus. However, the components of B. abortus involved in this phenomenon remained unknown. Prokaryotic RNA has been recently characterized as a special class of viability-associated PAMPs (vita-PAMPs). Thus, the aim of this study was to evaluate the effect of B. abortus RNA on IFN--induced MHC-I expression on human monocytes. For this, THP-1 cells were incubated with B. abortus RNA (0.1-20 µg/ml) in the presence of IFN- for 48 h. The expression of MHC-I molecules (HLA-ABC) was then evaluated by flow cytometry. B. abortus RNA significantly (p