Artículo
Brucella abortus inhibits major histocompatibility complex class II expression and antigen processing through interleukin-6 secretion via Toll-like receptor 2
Barrionuevo, Paula
; Cassataro, Juliana
; Delpino, María Victoria
; Zwerdling, Astrid
; Pasquevich, Karina Alejandra
; Garcia Samartino, Clara
; Wallach, Jorge Carlos; Fossati, Carlos Alberto
; Giambartolomei, Guillermo Hernan
Fecha de publicación:
12/2008
Editorial:
American Society for Microbiology
Revista:
Infection and Immunity
ISSN:
0019-9567
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The strategies that allow Brucella abortus to survive inside macrophages for prolonged periods and to avoid the immunological surveillance of major histocompatibility complex class II (MHC-II)-restricted gamma interferon (IFN-γ)-producing CD4+ T lymphocytes are poorly understood. We report here that infection of THP-1 cells with B. abortus inhibited expression of MHC-II molecules and antigen (Ag) processing. Heat-killed B. abortus (HKBA) also induced both these phenomena, indicating the independence of bacterial viability and involvement of a structural component of the bacterium. Accordingly, outer membrane protein 19 (Omp19) a prototypical B. abortus lipoprotein, inhibited both MHC-II expression and Ag processing to the same extent as HKBA. Moreover, a synthetic lipohexapeptide that mimics the structure of the protein lipid moiety also inhibited MHC-II expression, indicating that any Brucella lipoprotein could down-modulate MHC-II expression and Ag processing. Inhibition of MHC-II expression and Ag processing by either HKBA or lipidated Omp19 (L-Omp19) depended on Toll-like receptor 2 and was mediated by interleukin-6. HKBA or L-Omp19 also inhibited MHC-II expression and Ag processing of human monocytes. In addition, exposure to the synthetic lipohexapeptide inhibited Ag-specific T-cell proliferation and IFN-γ production of peripheral blood mononuclear cells from Brucella-infected patients. Together, these results indicate that there is a mechanism by which B. abortus may prevent recognition by T cells to evade host immunity and establish a chronic infection.
Palabras clave:
BRUCELLA
,
IMMUNOMODULATION
,
INFECTION
,
HISTOCOMPATIBILITY COMPLEZ CLASS II
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Identificadores
Colecciones
Articulos(IDEHU)
Articulos de INST.DE EST.DE LA INMUNIDAD HUMORAL PROF.R.A.MARGNI
Articulos de INST.DE EST.DE LA INMUNIDAD HUMORAL PROF.R.A.MARGNI
Articulos(INIGEM)
Articulos de INSTITUTO DE INMUNOLOGIA, GENETICA Y METABOLISMO
Articulos de INSTITUTO DE INMUNOLOGIA, GENETICA Y METABOLISMO
Citación
Barrionuevo, Paula; Cassataro, Juliana; Delpino, María Victoria; Zwerdling, Astrid; Pasquevich, Karina Alejandra; et al.; Brucella abortus inhibits major histocompatibility complex class II expression and antigen processing through interleukin-6 secretion via Toll-like receptor 2; American Society for Microbiology; Infection and Immunity; 76; 1; 12-2008; 250-262
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