Unopposed IL-18 signaling leads to severe TLR9-induced macrophage activation syndrome in mice.
Blood
; 131(13): 1430-1441, 2018 03 29.
Article
en En
| MEDLINE
| ID: mdl-29295842
ABSTRACT
The term macrophage activation syndrome (MAS) defines a severe, potentially fatal disorder characterized by overwhelming inflammation and multiorgan involvement. Interleukin-18 (IL-18) is a proinflammatory cytokine belonging to the IL-1 family, the activity of which is regulated by its endogenous inhibitor IL-18 binding protein (IL-18BP). Elevated IL-18 levels have been reported in patients with MAS. Herein, we show that on repeated toll-like receptor 9 (TLR9) stimulation with unmethylated cytosine guanine dinucleotide containing single-stranded DNA (CpG), IL-18BP-/- mice display severe MAS manifestations, including increased weight loss, splenomegaly, anemia, thrombocytopenia, hyperferritinemia, and bone marrow hemophagocytosis as compared with wild-type mice. Serum-free IL-18 was detected in CpG-treated IL-18BP-/- mice only. Levels of interferon-γ (IFN-γ) and of IFN-γ signature genes, such as the chemokine Cxcl9 or the transcription factor CIIta, were significantly increased in IL-18BP-/- mice. Blocking IL-18 receptor signaling attenuated the severity of MAS and IFN-γ responses in IL-18BP-/- mice. Blocking IFN-γ had comparable effects to IL-18 inhibition on most MAS manifestations. Our data indicate that endogenous IL-18BP exerts a protective role in CpG-induced MAS and that IL-18, which acts upstream of IFN-γ, is involved in the severity of MAS.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Transducción de Señal
/
Interleucina-18
/
Receptor Toll-Like 9
/
Síndrome de Activación Macrofágica
Límite:
Animals
Idioma:
En
Revista:
Blood
Año:
2018
Tipo del documento:
Article
País de afiliación:
Suiza