Generation mechanism of RANKL(+) effector memory B cells: relevance to the pathogenesis of rheumatoid arthritis.
Arthritis Res Ther
; 18: 67, 2016 Mar 16.
Article
em En
| MEDLINE
| ID: mdl-26980135
ABSTRACT
BACKGROUND:
The efficacy of B cell-depleting therapies for rheumatoid arthritis underscores antibody-independent functions of effector B cells such as cognate T-B interactions and production of pro-inflammatory cytokines. Receptor activator of nuclear factor κB ligand (RANKL) is a key cytokine involved in bone destruction and is highly expressed in synovial fluid B cells in patients with rheumatoid arthritis. In this study we sought to clarify the generation mechanism of RANKL(+) effector B cells and their impacts on osteoclast differentiation.METHODS:
Peripheral blood and synovial fluid B cells from healthy controls and patients with rheumatoid arthritis were isolated using cell sorter. mRNA expression of RANKL, osteoprotegerin, tumor necrosis factor (TNF)-α, and Blimp-1 was analyzed by quantitative real-time polymerase chain reaction. Levels of RANKL, CD80, CD86, and CXCR3 were analyzed using flow cytometry. Functional analysis of osteoclastogenesis was carried out in the co-culture system using macrophage RAW264 reporter cells.RESULTS:
RANKL expression was accentuated in CD80(+)CD86(+) B cells, a highly activated B-cell subset more abundantly observed in patients with rheumatoid arthritis. Upon activation via B-cell receptor and CD40, switched-memory B cells predominantly expressed RANKL, which was further augmented by interferon-γ (IFN-γ) but suppressed by interleukin-21. Strikingly, IFN-γ also enhanced TNF-α expression, while it strongly suppressed osteoprotegerin expression in B cells. IFN-γ increased the generation of CXCR3(+)RANKL(+) effector B cells, mimicking the synovial B cell phenotype in patients with rheumatoid arthritis. Finally, RANKL(+) effector B cells in concert with TNF-α facilitated osteoclast differentiation in vitro.CONCLUSIONS:
Our current findings have shed light on the generation mechanism of pathogenic RANKL(+) effector B cells that would be an ideal therapeutic target for rheumatoid arthritis in the future.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Artrite Reumatoide
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Subpopulações de Linfócitos B
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Ligante RANK
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Memória Imunológica
Tipo de estudo:
Etiology_studies
Limite:
Adult
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Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article