BAFF promotes regulatory T-cell apoptosis and blocks cytokine production by activating B cells in primary biliary cirrhosis
Rev. bras. pesqui. méd. biol
; Braz. j. med. biol. res;46(5): 433-439, maio 2013. graf
Article
em En
| LILACS
| ID: lil-675673
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BR1.1
ABSTRACT
Primary biliary cirrhosis (PBC) is a chronic and slowly progressive cholestatic liver disease of autoimmune etiology. A number of questions regarding its etiology are unclear. CD4+CD25+ regulatory T cells (Tregs) play a critical role in self-tolerance and, for unknown reasons, their relative number is reduced in PBC patients. B-cell-activating factor (BAFF) is a key survival factor during B-cell maturation and its concentration is increased in peripheral blood of PBC patients. It has been reported that activated B cells inhibit Treg cell proliferation and there are no BAFF receptors on Tregs. Therefore, we speculated that excessive BAFF may result in Treg reduction via B cells. To prove our hypothesis, we isolated Tregs and B cells from PBC and healthy donors. BAFF and IgM concentrations were then analyzed by ELISA and CD40, CD80, CD86, IL-10, and TGF-β expression in B cells and Tregs were measured by flow cytometry. BAFF up-regulated CD40, CD80, CD86, and IgM expression in B cells. However, BAFF had no direct effect on Treg cell apoptosis and cytokine secretion. Nonetheless, we observed that BAFF-activated B cells could induce Treg cell apoptosis and reduce IL-10 and TGF-β expression. We also showed that BAFF-activated CD4+ T cells had no effect on Treg apoptosis. Furthermore, we verified that bezafibrate, a hypolipidemic drug, can inhibit BAFF-induced Treg cell apoptosis. In conclusion, BAFF promotes Treg cell apoptosis and inhibits cytokine production by activating B cells in PBC patients. The results of this study suggest that inhibition of BAFF activation is a strategy for PBC treatment.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Bezafibrato
/
Linfócitos B
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Citocinas
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Apoptose
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Linfócitos B Reguladores
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Cirrose Hepática Biliar
Limite:
Female
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Humans
/
Male
Idioma:
En
Revista:
Braz. j. med. biol. res
/
Rev. bras. pesqui. méd. biol
Assunto da revista:
BIOLOGIA
/
MEDICINA
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
China
País de publicação:
Brasil