Mesenchymal Stem Cell Enhances the Function of MDSCs in Experimental Sjögren Syndrome.

Primary Sjögren's syndrome (pSS) is a progressive systemic autoimmune disease characterized by lymphocytic infiltrates in exocrine glands, leading to the injury of salivary and lachrymal glands. Mesenchymal stem cells (MSCs) have been demonstrated to exert great potential in the treatment of various autoimmune diseases. Although MSCs have provide an effective therapeutic approach for SS treatment, the underlying mechanisms are still elusive. Our previous study has shown the reduced suppressive capacity of myeloid-derived suppressor cells (MDSCs) advanced the progression of experimental Sjögren's syndrome (ESS). In this study, we found that BM-MSCs significantly enhanced the suppressive function of MDSCs with high levels of Arginase and NO, decreased the levels of CD40, CD80, CD86, and MHC-II expression on MDSCs, thus attenuating the disease progression in ESS mice. Furthermore, the enhanced suppressive function of MDSCs was mediated by BM-MSC-secreted TGF-ß, and the therapeutic effect of BM-MSCs in inhibiting ESS was almost abolished after silencing TGF-ß in BM-MSCs. Taken together, our results demonstrated that BM-MSCs alleviated the ESS progression by up-regulating the immunosuppressive effect of MDSCs through TGF-ß/Smad pathway, offering a novel mechanism for MSCs in the treatment of pSS.

Histone deacetylase inhibitor regulates the balance of Th17/Treg in allergic asthma.

BACKGROUND AND AIMS: The aim of this study is to investigate the expression pattern of histone deacetylase 9 in peripheral blood of patients with allergic asthma and its regulatory effect on the balance of Th17/Treg cells involved in the pathogenesis of asthma. METHODS: flap-Ub promoter-GFP-WRE vector was used to construct the Jurkat-HA-FOXP3 cell line. After histone deacetylase inhibitor-trichostatin A (TSA) treatment, FOXP3 and RORγt expression were detected by real-time-polymerase chain reaction (RT-PCR). BALB/c mice were randomly assigned to control group, TSA treatment and the asthma group. Serum Immunoglobulin E (IgE) was detected with enzyme-linked immunosorbent assay (ELISA), airway inflammation in lung tissue evaluated by haematoxylin/eosin staining, bronchoalveolar lavage fluid (BALF) cell number and differential counted, interleukin (IL)-17A and TGF-ß concentrations in BALF measured with ELISA, and expression of RORγt and FOXP3 messenger RNA (mRNA)measured by RT-PCR. Forty-seven patients with asthma were recruited and assigned to intermittent, mild and moderate-severe group. GATA3, IL-4, histone deacetylases (HDAC) 9 mRNA expression level were measured by RT-PCR. RESULTS: After TSA treatment, FOXP3 mRNA level was upregulated, while RORγt mRNA level was downregulated. FOXP3 protein level was also upregulated by TSA. In vivo, TSA treatment can inhibit IL-17 but promote transforming growth factor-beta production in the BALF of asthma mice, and inhibited the expression of Th17 cells and RORγt mRNA in lung; also can promote Foxp3 mRNA expression. GATA3, IL-4 mRNA expression levels were upregulated in patients with asthma than the healthy control. HDAC9 mRNA expression level was associated with the severity of disease. CONCLUSION: The histone deacetylase inhibitor TSA can regulate the balance of Th17/Treg in asthma by regulating the activity of histone deacetylase.

An increased ratio of Th2/Treg cells in patients with moderate to severe asthma.

BACKGROUND: Recent studies have shown that T helper type-2 (Th2) cells can induce the apoptosis of CD4+CD25+ Treg cells or resist the immunosuppressive effect of Treg cells. We hypothesize that an imbalance of Th2/Treg is present in patients with allergic asthma. METHODS: Twenty-two patients with mild asthma, 17 patients with moderate to severe asthma, and 20 healthy donors were enrolled. All patients were allergic to house dust mites. The proportion of peripheral blood CD4+CD25+ Treg cells and Th2 cells were determined by flow cytometry. The concentration of interleukin (IL)-10, transforming growth factor (TGF)-ß and IL-4 in plasma was determined by enzyme linked immunosorbent assay. In these subjects, peripheral blood mononuclear cells from 17 mild asthmatic patients, 13 moderate to severe asthmatic patients and 14 healthy donors were acquired and expression of forkhead box P3 (Foxp3) and GATA-3 mRNA was detected by reverse-transcriptase polymerase chain reaction. RESULTS: Compared with healthy donors and patients with mild asthma, the percent of CD4+CD25+ Treg cells and plasma IL-10 levels were decreased in patients with moderate to severe asthma. There were no significant differences in Foxp3 mRNA expression among three groups, but a downward trend seen among patients with asthma. However, the percent of Th2 cells, IL-4 levels and expression of GATA-3 mRNA was markedly higher in patients with mild and moderate to severe asthma than in the control group. The ratio of Th2/Treg and their cytokines was increased in allergic asthma, especially for moderate to severe asthma. The ratio of GATA-3/Foxp3 mRNA was also increased in allergic asthma. In patients with moderate to severe asthma, the percentage of peripheral blood Treg cells was negatively correlated to the percentage of Th2 cells and IL-4 levels. CONCLUSIONS: The decline of CD4+CD25+ Treg cells in patients with moderate to severe asthma may play an important role in progress of the disease. Furthermore, the deficiency of CD4+CD25+ Treg cells was associated with the over-expression of Th2 response.

[Characteristics of histone deacetylase 9 in peripheral blood of patients with bronchial asthma].

OBJECTIVE: To investigate the expression pattern of histone deacetylase 9 (HDAC9) in peripheral blood of asthmatics and its effect on immune cells (Th2, Th17, Tregs) involved in the pathogenesis of asthma. METHODS: Forty-seven asthmatics from Ruijin Hospital were recruited and assigned to intermittent, mild and moderate-severe groups. Lung function test and Asthma Control Questionnaire were performed to evaluate asthma control and severity. Twenty healthy donors were enrolled as controls. GATA3, IL-4, and HDAC9 mRNA expression levels were measured by SYRB Green Real-time PCR. The cytokine IL-17-mainly produced by Th17 cells and TGF-ß-mainly produced by Treg cells, were measured by ELISA. RESULTS: The GATA3 and IL-4 mRNA expression levels (28.12 ± 7.57 and 743.6 ± 312.8) were up-regulated in asthmatics as compared to the healthy controls [0.56 ± 0.22, 0.7 ± 0.8 (U = 16.00, 37.00, P < 0.01)]. The HDAC9 mRNA expression levels of intermittent, mild and moderate-severe groups were 3.20 ± 0.50, 89.6 ± 18.0, 323.0 ± 65.3, respectively, which were associated with the severity of disease (H = 11.32, P < 0.05). The level of IL-17 in asthmatic group was (83 ± 55) ng/L, which was up-regulated as compared to the healthy control [(34 ± 22) ng/L (U = 153.50, P < 0.01)]. The level of TGF-ß was decreased in the asthmatic groups as compared to the healthy control, but the difference did not reach significance. HDAC9 mRNA expression level was positively correlated with GATA3 mRNA expression level (r = 0.482, P < 0.05), and also with IL-4 mRNA expression (r = 0.432, P < 0.05) and IL-17 (r = 0.538, P < 0.05), but negatively correlated with TGF-ß (r = -0.417, P < 0.05). In patients with moderate-severe asthma, HDAC9 mRNA expression level was negatively correlated with FEV(1)% (r = -0.657, P < 0.05). CONCLUSION: HDAC9 mRNA expression was up-regulated in peripheral blood of asthmatics, which was not only associate with the Th2 master transcriptional factors GATA3, cytokine IL-4 mRNA, Th17 and Treg cell-related cytokines, but also with FEV(1)% in moderate-severe asthma.

Coexistence of Th1/Th2 and Th17/Treg imbalances in patients with allergic asthma.

BACKGROUND: Recent recognition is that Th2 response is insufficient to fully explain the aetiology of asthma. Other CD4(+) T cells subsets might play a role in asthma. We investigated the relative abundance and activities of Th1, Th2, Th17 and CD4(+)CD25(+) Treg cells in patients with allergic asthma. METHODS: Twenty-two patients with mild asthma, 17 patients with moderate to severe asthma and 20 healthy donors were enrolled. All patients were allergic to house dust mites. Plasma total IgE, pulmonary function and Asthma Control Questionnaire were assessed. The proportions of peripheral blood Th1, Th2, Th17 and CD4(+)CD25(+) Treg cells were determined by flow cytometry. The expression of cytokines in plasma and in the culture supernatant of peripheral blood mononuclear cells was determined by enzyme linked, immunosorbent assay. RESULTS: The frequency of blood Th2 cells and IL-4 levels in plasma and culture supernatant of peripheral blood mononuclear cells were increased in all patients with allergic asthma. The frequency of Th17 cells and the plasma and culture supernatant levels of IL-17 were increased, whereas the frequency of CD4(+)CD25(+) Treg cells and plasma IL-10 levels were decreased in patients with moderate to severe asthma. Dermatophagoides pteronyssinus specific IgE levels were positively correlated with the percentage of blood Th2 cells and plasma IL-4 levels. Forced expiratory volume in the first second was negatively correlated with the frequency of Th17 cells and plasma IL-17 levels, and positively correlated with the frequency of Treg cells. However, mean Asthma Control Questionnaire scores were positively correlated with the frequency of Th17 cells and plasma IL-17 levels, and negatively correlated with the frequency of Treg cells. CONCLUSIONS: Imbalances in Th1/Th2 and Th17/Treg were found in patients with allergic asthma. Furthermore, elevated Th17 cell responses, the absence of Tregs and an imbalance in Th17/Treg levels were associated with moderate to severe asthma.