Methylprednisolone pulse therapy promotes the differentiation of regulatory T cells by inducing the apoptosis of CD4+ T cells in patients with systemic lupus erythematosus.

OBJECTIVES: To investigate the differentiation of regulatory T cells (Tregs) induced by methylprednisolone (MP) pulse therapy in patients with Systemic Lupus Erythematosus (SLE). METHODS: We enrolled 30 patients with SLE and analyzed peripheral blood mononuclear cells (PBMCs) before and after MP pulse therapy. Peripheral Tregs, apoptosis of PBMCs subsets, and TGFß production by monocytes was quantified by flow cytometry. Proliferation and IFN-γ production of CD4+ T cells were measured. Furthermore, TGFß1 production by human monocyte-derived macrophages (HMDM) stimulated with MP-treated CD4+ T cells were quantified by ELISA. RESULTS: Peripheral Tregs was significantly increased after MP pulse therapy (6.76 ± 1.46% vs. 3.82 ± 1.02%, p < 0.01), with an expansion of Nrp1- induced Tregs (4.54 ± 0.46% vs. 1.75 ± 0.38%, p < 0.01). Proliferation and IFN-γ production of CD4+ T cells were significantly decreased after MP pulse therapy. MP pulse therapy induced CD4+ T cell apoptosis (early apoptosis, 26.34 ± 3.54% vs. 14.81 ± 2.89%, p < 0.01) and TGFß expression on monocytes (6.02% vs. 2.45%, p < 0.01). Furthermore, MP induced CD4+ T cell apoptosis in vitro, which stimulated HMDM to produce TGFß. Moreover, elevated TGFß level in supernatant from HMDM stimulated with MP-treated CD4+ T cells promoted Tregs differentiation. CONCLUSIONS: MP pulse therapy induces CD4+ T cell apoptosis, which promotes monocytes to produce TGFß and further facilitates Tregs differentiation. Newly-differentiated Tregs suppress proliferation and IFN-γ production of CD4+ T cells and contribute to immunoregulatory milieu after MP pulse therapy.

Elevated EPSTI1 promote B cell hyperactivation through NF-κB signalling in patients with primary Sjögren's syndrome.

BACKGROUND: Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterised by aberrant B cell hyperactivation, whose mechanism is partially understood. METHODS: We performed whole transcriptome sequencing of B cells from three pSS patients and three matched healthy controls (HC). Differentially expression genes (DEGs) were confirmed with B cells from 40 pSS patients and 40 HC by quantitative PCR and western blot. We measured the proliferation potential and immunoglobulins production of siRNA-transfected or plasmid-transfected B cells stimulated with cytosine-phosphate-guanine (CpG) or anti-IgM. We also explored Toll-like receptor 9 (TLR9) signalling to reveal the potential mechanism of B cell hyperactivation in pSS. RESULTS: We identified 77 upregulated and 32 downregulated DEGs in pSS B cells. We confirmed that epithelial stromal interaction (EPST1) expression in pSS B cells was significantly higher than that from HCs. EPSTI1-silencing B cells stimulated with CpG were less proliferated and produced lower level of IgG and IgM comparing with control B cells. EPSTI1-silencing B cells expressed lower level of p-p65 and higher level of IκBα, and B cells with overexpressed EPSTI1 showed higher level of p-p65 and lower level of IκBα. Finally, IκBα degradation inhibitor Dehydrocostus Lactone treatment attenuated p65 phosphorylation promoted by EPSTI1. CONCLUSION: Elevated EPSTI1 expression in pSS B cells promoted TLR9 signalling activation and contributed to the abnormal B cell activation, which was promoted by facilitating p65 phosphorylation and activation of NF-κB signalling via promoting IκBα degradation. EPSTI1 might be implicated in pSS pathogenesis and was a potential therapeutic target of pSS.