Negative regulation of inflammatory responses by immunoglobulin A receptor (FcαRI) inhibits the development of Toll-like receptor-9 signalling-accelerated glomerulonephritis.
Clin Exp Immunol
; 166(2): 235-50, 2011 Nov.
Article
em En
| MEDLINE
| ID: mdl-21985370
ABSTRACT
Myeloid FcαRI, a receptor for immunoglobulin (Ig)A, mediates cell activation or inhibition depending on the type of ligand interaction, which can be either multivalent or monovalent. Anti-inflammatory signalling is triggered by monomeric targeting using anti-FcαRI Fab or IgA ligand binding, which inhibits immune and non-immune-mediated renal inflammation. The participation of Toll-like receptors (TLRs) in kidney pathology in experimental models and various forms of human glomerular nephritis has been discussed. However, little is known about negative regulation of innate-immune activation. In the present study, we generated new transgenic mice that express FcαRI(R209L) /FcRγ chimeric protein and showed that the monovalent targeting of FcαRI exhibited inhibitory effects in an in vivo model of TLR-9 signalling-accelerated nephritis. Mouse monoclonal anti-FcαRI MIP8a Fab improved urinary protein levels and reduced the number of macrophages and immunoglobulin deposition in the glomeruli. Monovalent targeting using MIP8a Fab attenuates the TLR-9 signalling pathway and is associated with phosphorylation of extracellular signal-related protein kinases [extracellular signal-regulated kinase (ERK), P38, c-Jun N-terminal kinase (JNK)] and the activation of nuclear factor (NF)-κB. The inhibitory mechanism involves recruitment of tyrosine phosphatase Src homology 2 domain-containing phosphatase-1 (SHP-1) to FcαRI. Furthermore, cell transfer studies with macrophages pretreated with MIP8a Fab showed that blockade of FcαRI signalling in macrophages prevents the development of TLR-9 signalling-accelerated nephritis. These results suggest a role of anti-FcαRI Fab as a negative regulator in controlling the magnitude of the innate immune response and a new type of anti-inflammatory drug for treatment of kidney disease.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Imunoglobulina A
/
Receptores Fc
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Antígenos CD
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Receptor Toll-Like 9
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Glomerulonefrite
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article