Different roles of TiR8/Sigirr on toll-like receptor signaling in intrarenal antigen-presenting cells and tubular epithelial cells.
Kidney Int
; 72(2): 182-92, 2007 Jul.
Article
en En
| MEDLINE
| ID: mdl-17495864
Toll-like receptors (TLRs) exist on both myeloid and intrinsic renal cells contributing to the initiation of innate immunity during renal infection with uropathogenic Escherichia coli. Toll-interleukin 1 receptor (IL-1R) (TIR)8/SIGIRR is an orphan receptor of the TLR/IL-1R family, which suppresses TLR signaling of immune cells and is highly expressed in the kidney. Lack of TIR8/SIGIRR is associated with enhanced renal chemokine signaling upon exposure to lipopolysaccharide (LPS). This was because of TIR8/SIGIRR expression on resident intrarenal myeloid cells rather than tubular epithelial cells which express it on basolateral and luminal membranes. The lack of TIR8/SIGIRR does not enhance TLR/IL-1R signaling in tubular epithelial cells as was observed in monocytes. TIR8/SIGIRR is induced in monocytes treated with LPS or tumor necrosis factor and interferon-gamma in a dose-dependent manner but was downregulated in treated tubule epithelial cells. This cell type-specific regulation and function did not relate to mRNA splice variants but was associated with N- and O-glycosylation of the receptor in renal cells of myeloid and nonmyeloid origin. Our studies show that resident myeloid cells contribute to TLR-mediated antimicrobial immunity in the kidney and that this function is controlled by Tir8/sigirr. TIR8/SIGIRR does not suppress TLR signaling in tubular epithelial cells, which supports their role as sensors of microbial infection in the kidney.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Receptores de Interleucina-1
/
Células Epiteliales
/
Receptores Toll-Like
/
Riñón
/
Células Presentadoras de Antígenos
Límite:
Animals
Idioma:
En
Revista:
Kidney Int
Año:
2007
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Estados Unidos