SAT0278 LOW-DOSE IL-2 RESTORES TREG-MEDIATED IMMUNE TOLERANCE IN PATIENTS WITH ANCA-ASSOCIATED VASCULITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1083-1084
Author(s):  
R. Wu ◽  
R. Su ◽  
T. Ding ◽  
H. Xue ◽  
J. An ◽  
...  

Background:Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of autoimmune disease that can cause systemic organ damage, including granulomatosis with polyangiitis(GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis(EGPA)[1]. Several observations have showed that the breakdown of immune tolerance was involved in the pathogenesis of AAV [2], furthermore, a single, open and clinical trial demonstrates that IL-2 can be used to treat patients with GPA [3]. But there is still a lack of understanding of the relationship between Th17 / Treg and AAV and evidence for the therapeutic effect of IL-2 on AAV, which needs further exploration.Objectives:We first measured the absolute number of CD4+T subsets in peripheral blood of patients to explore the pathogenesis of AAV, and then investigated the effects of short-term and low-dose recombinant human IL-2 (rhIL-2) on CD4+T subsets of patients to analyze the regulatory effect of IL-2 on AAV.Methods:49 patients with AAV, hospitalized at the Second Hospital of Shanxi Medical University from the May 2016 to the November 2019 were enrolled, including 36 patients who were only received conventional glucocorticoids and DMARDs, and other 13 patients who were not only received these treatments but were also injected subcutaneously rhIL-2(50WIU/day for a 5-day course). 31 age and gender-matched healthy adults were selected as controls. The absolute number of Th17 and Treg cells in peripheral blood of health controls and the patients before and after treatment was detected by flow cytometry.Results:There was significant decreased level of Treg cells in the patients with AAV compared with healthy controls (P<0.001) leading to a higher Th17/Treg ratio in the patients with AAV, but there was no statistically significant in the absolute number of Th17 cells between the patients and healthy controls. After the treatment of short-term and low-dose IL-2, there was a significant increase in the absolute number of Treg cells (P<0.01) leading to a decrease in the ratio of Th17 and Treg (p<0.05).The absolute number of Th17 had a trend towards higher values but was not statistical significance.Conclusion:The difference of Treg cells between the patients and healthy controls suggested that the decreased number of Treg cells failed to control autoimmune inflammatory response contributing to the pathogenesis of AAV. After the treatment of short-term and low-dose rhIL-2, there was a more significant increase in the absolute number of Treg cells showing that IL-2 could selectively stimulate the growth of Treg cells and restore the Treg-mediated immune tolerance in patients with AAV to achieve disease remission.References:[1]Cosmi, L.,Th17 and Treg lymphocytes as cellular biomarkers of disease activity in Granulomatosis with Polyangiitis.Eur J Immunol, 2017.47(4): p. 633-636.[2]Pagnoux, C.,Updates in ANCA-associated vasculitis.Eur J Rheumatol, 2016.3: p. 122-133.[3]Rosenzwajg, M., et al.,Immunological and clinical effects of low-dose interleukin-2 across 11 autoimmune diseases in a single, open clinical trial.Annals of the Rheumatic Diseases, 2019.78(2): p. 209-217.Disclosure of Interests:None declared

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 392-392
Author(s):  
R. Wu ◽  
R. Su ◽  
T. Ding ◽  
H. Xue ◽  
J. An ◽  
...  

Background:Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of autoimmune disease that can cause systemic organ damage, characterized with the presence of abnormal antibodies (ANCAs) in the circulation and the small- and medium-vessel vasculitis[1].However,the etiology of AAV remained unclear. Several observations have showed that the breakdown of immune tolerance caused by many complex interactions was involved in the pathogenesis of AAV[2].It has been confirmed that the disorder of the CD4+T cell,especially the imbalance of Th17 and Treg cells can destroy the immune tolerance and cause many autoimmune disease[3]. But the relationship between the Th17/Treg and AAV is unknown.Objectives:We investigated the absolute numbers of CD4+T subsets cells in peripheral blood of patients with AAV and healthy adults,and then compared them in different disease activity of AAV to explore the role of CD4+T subsets cells in the pathogenesis and development of AAV.Methods:49 patients with AAV,hospitalized at the Second Hospital of Shanxi Medical University from the May 2016 to the November 2019 were enrolled, and 31 age and gender-matched healthy adults were anticipated as controls.According to BVAS, the patients were divided into disease-activity group (BVAS≥15, n=27) and non-disease-activity group (BVAS<15, n=22). The absolute numbers of CD4+T subsets cells including Th17 and Tregs in peripheral blood of these individuals were detected by flow cytometry.We analyzed whether there was difference of CD4+T subsets between the patients and healthy controls,and between disease-activity group and non-disease-activity group.Results:There was significant decreased level of Treg cells in the patients with AAV compared with healthy controls,especially in the disease-activity group. The absolute numbers of Treg cells was decreased in the patients with AAV compared with healthy controls (P<0.001) leading to a higher Th17/Treg ratio in the patients (P<0.01).Similarly,the absolute number of Treg cells was decreased in the disease- activity group (P<0.01) compared with the non-disease-activity group, and the absolute number of Treg cells was significant negative correlation with the disease activity indexes such as BVAS (r=-0.342,P=0.016), erythrocyte sedimentation rate(ESR) (r=-0.315,P=0.027) and C-reactive protein(CRP) (r=-0.305,P=0.033). But there was no statistically significant in the absolute number of Th17 cells between the patients and healthy controls, and between disease-activity group and non-disease-activity group.Conclusion:The results we investigated here suggested that the decreased number of Treg cells failed to control autoimmune inflammatory response and maintain immune tolerance, and the disease activity of AAV was associated with the reduced number of Treg cells.Figure 1.(A-C) Characteristics of the absolute number of Th17 cells and Treg cells in peripheral blood of healthy controls (n=31) and the patients with AAV (n=49). There was significant decreased level of Treg cells in the patients with AAV compared with healthy controls leading to a higher Th17/Treg ratio in the patients with AAV. (D-F) The absolute number of Treg cells was decreased in the disease- activity group (n=27) compared with the non-disease-activity group (n=21). The absolute number of Th17 cells and Treg cells was detected by flow cytometry. Statistical analyses were performed by the Mann-Whitney U test. *p<0.05,**p<0.01, ***p<0.001.References:[1]Cosmi, L., Th17 and Treg lymphocytes as cellular biomarkers of disease activity in Granulomatosis with Polyangiitis. Eur J Immunol, 2017.47(4): p. 633-636.[2]Pagnoux, C.,Updates in ANCA-associated vasculitis.Eur J Rheumatol, 2016.3: p. 122-133.[3]Diller, M.L., et al., Balancing Inflammation: The Link between Th17 and Regulatory T Cells. Mediators Inflamm, 2016.2016: p. 6309219.Disclosure of Interests:None declared


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 427-428
Author(s):  
R. Wu ◽  
J. An ◽  
T. Ding ◽  
H. Xue ◽  
X. F. Li ◽  
...  

Background:Rheumatoid arthritis (RA) is a systemic autoimmunity inflammation disease characterized with chronic aggressive arthritis and the presence of abnormal antibodies. Several observations showed that the breakdown of immune tolerance caused by many complex interactions was involved in the development of RA[1]. However, the pathogenesis of RA remained unclear. It has been confirmed that the imbalance of Th17 and Treg cells play a crucial role in destroying immune tolerance [2]. Besides, researches showed that intestinal microbiota can influence host immunity by acting on the immune cells to play pro-inflammatory or anti-inflammatory effect, and in turn immune system can also regulate the microbiota[3, 4]. Thus, a frontier point of view in the field of rheumatism, immune microecology, was proposed, which is a novel concept for the breakdown of immune tolerance. Studies have confirmed that there was an imbalance of intestinal microbiota in patients with RA [4]. But the relationship between the CD4+T subsets cells and intestinal microbiota in RA is unknown.Objectives:We detected and compared the absolute number of CD4+T cells subsets in the peripheral blood and the proportion or abundance of intestinal microbiota in patients with RA and healthy adults, and then analyzed the relationship between them to explore the role of CD4+T cells subsets and intestinal microbiota in the pathogenesis of RA.Methods:We collected the sample of stool and blood from 15 patients with RA hospitalized at the Second Hospital of Shanxi Medical University and 8 age and gender-matched healthy controls(HC). The absolute number of CD4+T cells subsets including Th1, Th2, Th17 and Treg cells were detected by flow cytometry. The 16S rRNA in the stool specimens were sequenced by the Roche/45 high-throughput sequencing platform. We analyzed whether there was correlarion between CD4+T subsets cells and intestinal microbiota.Results:Patients with RA had a higher level of Christensenellaceae and a lower level of Pseudomonadaceae as compared with those of HCs at the family level (p<0.05). And at the genus level, the patients with RA had higher levels of Ruminococcus torques, Christensenellaceae R-7, Ruminiclostridium 9 and Ruminococcus 1 compared with those of HCs (p<0.05) (Figure 1).And the Ruminococcus torques at the genus level was negative correlated with the absolute number of Treg cells (p<0.001) (Figure 2).Conclusion:The results here suggested that there were different proportion or abundance of intestinal microbiota between the patients with RA andHCs. And the changes of intestinal microbiota such as Ruminococcus torques were associated with Treg cells, further indicating that the imbalance of intestinal microbiota in RA can destory the immune tolerance. The above results uncovered that the intestinal microbiota had immunomodulatory function, which may be the upstream mechanism participated in the pathogenesis of RA.References:[1]Weyand CM, Goronzy JJ. The immunology of rheumatoid arthritis. Nat Immunol 2021, 22(1): 10-18.[2]Weyand CM, Goronzy JJ. Immunometabolism in the development of rheumatoid arthritis. Immunol Rev 2020, 294(1): 177-187.[3]Brown EM, Kenny DJ, Xavier RJ. Gut Microbiota Regulation of T Cells During Inflammation and Autoimmunity. Annu Rev Immunol 2019, 37: 599-624.[4]du Teil Espina M, Gabarrini G, Harmsen HJM, Westra J, van Winkelhoff AJ, van Dijl JM. Talk to your gut: the oral-gut microbiome axis and its immunomodulatory role in the etiology of rheumatoid arthritis. FEMS Microbiol Rev 2019, 43(1).Figure 1.At the family level (a-b) and the genus level(c-f), the relative abundance of intestinal microbiota in patients with RA and HCs were different. Data were expressed as median (Q1, Q3) and analyzed by Wilcoxon test. (*** P < 0.001, **P < 0.01 and *P < 0.05).Figure 2.A heatmap shows the correlation between the intestinal microbiota and CD4+T cells in patients with RA, and Ruminococcus torques at the genus level was negative related with Treg cells. (Colors indicate the Spearman rank correlation, *** P < 0.001).Disclosure of Interests:None declared


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1591.3-1591
Author(s):  
Y. Liang ◽  
H. Y. Wen ◽  
Y. Duan ◽  
Y. Liu ◽  
Z. Yu ◽  
...  

Background:Idiopathic inflammatory myopathies (IIM) are featured by a series of clinical presentation such as proximal muscle weakness, increased serum levels of creatine kinase and other muscle enzymes and involvement of other organs and systems[1, 2], which results in high morbidity and early mortality[3]. We have known the changes of the level of Th17 and Treg cells in IIM in previous studies[4-6]. However, whether infection affects lymphocyte subsets or not and whether the effect of low-dose interleukin-2 (IL-2) can be influenced by the use of immunosuppressants or not are still unclear.Objectives:The study aimed to explore the changes of lymphocyte subsets in patients of IIM with or without important organ infection, and the restoration of Th17/Treg after receiving low-dose IL-2.Methods:A total of 118 IIM patients were enrolled and classified into infection group and non-infection group based on the important organ infection. Of them, 48 cases were treated with low dose IL-2 (5.0*105IU for 5 days). The absolute number of peripheral total T, B, CD4+T, CD8+T, NK, Th1, Th2, Th17 and Treg cell subsets were analyzed by flow cytometry combined with absolute counting beads. Clinical data, laboratory examinations and the levels of peripheral lymphocyte subsets were analyzed retrospectively.Results:In these patients, especially in the infection group, the absolute number of T, CD4+T, CD8+T, NK, Th1, Th2, Th17 and Treg cells were significantly decreased as compared with that in the healthy controls, which were significantly increased by low dose IL-2 (especially Treg cells) treatment. The levels of ESR, LDH and HBDH and the ratio of Th17/Treg were significantly lower than those before IL-2 treatment (Z=-2.237, -2.083, -2.140, -3.663,P=0.025, 0.037, 0.032, 0.000). The 48 cases who received IL-2 treatment were divided into 2 groups according to whether they used immunosuppressants. There was no significant difference in the absolute number of T, B, CD4+T, CD8+T, Th1, Th2, Th17 and Treg cells, the proportion of Th17 and Treg cells and the ratio of Th17/Treg between the 2 groups (P>0.05).Conclusion:Global decrease in lymphocyte subsets was found in IIM patients, especially those who had important organ infection. A significant re-balance of Th17/Treg was observed after receiving treatment with low-dose IL-2. Furthermore, the restoration of lymphocyte subsets showed similar degree after treatment with or without immunosuppressants. Low-dose IL-2 may become a potential therapy for IIM patients. The mechanism of lymphocyte decrease in IIM is required further to study.References:[1]Clark K E N, Isenberg D A. A review of inflammatory idiopathic myopathy focusing on polymyositis[J]. European Journal of Neurology, 2017.[2]Tieu J, Lundberg IE, Limaye V. Idiopathic inflammatory myositis. Best Pract Res Clin Rheumatol. 2016. 30(1): 149-68.[3]Mandel DE, Malemud CJ, Askari AD. Idiopathic Inflammatory Myopathies: A Review of the Classification and Impact of Pathogenesis. Int J Mol Sci. 2017. 18(5).[4]Zhang SX, Wang J, Sun HH, et al. Circulating regulatory T cells were absolutely decreased in dermatomyositis/polymyositis patients and restored by low-dose IL-2. Ann Rheum Dis. 2019 .[5]Espinosa-Ortega F, Gómez-Martin D, Santana-De Anda K, Romo-Tena J, Villaseñor-Ovies P, Alcocer-Varela J. Quantitative T cell subsets profile in peripheral blood from patients with idiopathic inflammatory myopathies: tilting the balance towards proinflammatory and pro-apoptotic subsets. Clin Exp Immunol. 2015. 179(3): 520-8.[6]Feng M, Guo H, Zhang C, et al. Absolute reduction of regulatory T cells and regulatory effect of short-term and low-dose IL-2 in polymyositis or dermatomyositis. Int Immunopharmacol. 2019. 77: 105912.Acknowledgments:Thanks for the support of my teachers, classmates and my family.Disclosure of Interests:None declared


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1542.1-1543
Author(s):  
W. Jia ◽  
J. Xie ◽  
X. Wang ◽  
C. Gao ◽  
G. Liu ◽  
...  

Background:Takayasu arteritis (TA) refers to chronic progressive non-specific inflammation that involves the aorta and its main branches, causing stenosis and occlusion of arteries in different parts, and ischemic manifestations in the corresponding parts. A variety of immune dysfunctions are involved in the occurrence and development of TA(1)Recent studies have shown that Th17/Treg imbalance plays an important role in the pathogenesis of Takayasu’s arteritis, in which T help 17 cells (Th17) cells are up-regulated in TA patients(2). Th17 cells are closely related to Treg cells during differentiation. There are few studies on the expression level of CD4+CD25+FOX3+T lymphocyte (Treg) cells. This study aims to study the clinical significance of Treg cell expression in peripheral blood of patients with Takayasu’s arteritis.Objectives:To analyze the levels of circulating lymphocyte subsets and serum cytokines in patients with takayasu arteritis (TA), and explore the relationship between their changes and TA disease activity.Methods:A total of 46 TA patients and 43 gender-age-matched healthy controls were enrolled. According to the NIH standard, 30 patients were in active disease. Flow cytometry was used to detect the absolute numbers and ratios of Th1, Th2, Th17 and Treg cells in peripheral blood of all subjects. Magnetic bead-based multiplex immunoassay was used to detect cytokines and statistical analysis was performed.Results:Compared with the healthy controls, the absolute number and proportion of peripheral Treg cells of TA patients significantly decreased while those of Th17 cells increased significantly, leading to the increased ratio of Th17 / Treg. Compared with the inactive group, the TA active group had significantly increased IL-6 and TNF-α, and there was no significant difference in the expression of Th17 cells and Treg cells.Conclusion:In peripheral blood of TA patients, Treg cells decreased, while Th17 cells increased as compared with healthay controls, leading to an imbalance between Th17 and Treg cells. The levels of IL-6 and TNF-α were related to disease activity.References:[1]Russo, R.A.G. and M.M. Katsicas, Takayasu Arteritis. Front Pediatr, 2018. 6: p. 265.[2]Misra, D.P., S. Chaurasia, and R. Misra. Increased Circulating Th17 Cells, Serum IL-17A, and IL-23 in Takayasu Arteritis. Autoimmune Dis, 2016. 2016: p. 7841718.Figure 1.Characteristics of the absolute numbers and proportions of Th1cells,Th2cells,Th17 cells and CD4Treg cells in the PB of patients with TA.(A-C)The levels of Th17 cells and the ratio of Th1/Treg,Th2/Treg,Th17/Treg in PB were significantly increased in patients with TA (n=46). The absolute number and the proportion of CD4Treg cells were significantly decreased in TA(n=46). (D-F) The absolute number of Th2 cells and ratio of Th2/Treg in PB were significantly decreased in active patients with TA (n=30).Neither the absolute number nor proporation of Th1, Th17 and Treg cells was altered significantly between active TA patients(n=30) and inactive TA patients(n=16).*P<0.05; **P<0.001. P<0.05 was considered statistically significant.TA,takayasu arteritis;PB peripheral blood;Tregs, regulatory Tcells.Figure 2.Characteristics of serum concentrations of cytokine (including IL-6, IL-10, IL-17 and TNF-α) between active TA patients(n=30) and inactive TA patients(n=16).(A,D)In terms of cytokines, the concentration of IL-6 and TNF-α was significantly up-regulated,(B,C)but no significant changes in IL-10, and IL-17 were found.*P<0.05; **P<0.001. P < 0.05 was considered statistically significant.Disclosure of Interests:None declared


2021 ◽  
Vol 13 ◽  
pp. 1759720X2110113
Author(s):  
Sheng-Xiao Zhang ◽  
Jia Wang ◽  
Cai-Hong Wang ◽  
Rui-Huan Jia ◽  
Ming Yan ◽  
...  

Background: Circulating regulatory T cells (Tregs) are responsible for mediating immune tolerance and maintaining immunological homeostasis. Decreases in Tregs may be involved in the onset of rheumatoid arthritis (RA). Low-dose interleukin-2 (IL-2) has been considered for the treatment of inflammatory diseases mediated by T cells. This study focused on the status of circulating CD4+T subsets and the clinical feasibility of IL-2 therapies in patients with RA. Methods: The subjects included 888 patients with RA and 100 healthy controls (HCs); 233 RA patients received IL-2 treatment with 0.5 million international units (MIU)/day from days 1 through 5. The demographic features, disease activity, and levels of CD4+T cells measured by modified flow cytometry were collected in all RA patients before and after treatment. Results: RA patients had lower absolute Treg counts (but not Th17) compared with HCs, which was associated with disease activity; previously treated RA patients had the fewest circulating Tregs ( p < 0.05). Patients treated with low-dose IL-2 had a three-fold increase in absolute anti-inflammatory Treg counts, as well as a two-fold increase in the other CD4+T subsets. Moreover, post-treatment levels of markers of disease activity in RA patients treated with IL-2 were significantly lower than the baseline values ( p < 0.001), with no apparent side effects. Conclusion: Decreased absolute counts of circulating CD4+T lymphocyte subsets were observed in patients with RA. Circulating Tregs, which mediate immune tolerance, may be involved in the pathogenesis and progression of RA; however, this was ameliorated by low-dose IL-2, without obvious side effects. Plain language summary Low-dose IL-2 treatment for rheumatoid arthritis • Circulating Tregs may be involved in the pathogenesis and progression of RA. • The absolute count of Tregs was significantly correlated with disease activity measures. • Low-dose IL-2 was able to effectively expade Tregs and help for RA patients’ symptoms remission without evaluated side effects.


2020 ◽  
Vol 29 ◽  
pp. 096368972091387 ◽  
Author(s):  
Seok-Joo Lee ◽  
Hyun-Je Kim ◽  
Na-ri Byun ◽  
Chung-Gyu Park

Anti-CD154 blockade-based regimens remain unequaled in prolonging graft survival in various organ transplantation models. Several studies have focused on transplantation tolerance with the anti-CD154 blockade, but none of these studies has investigated the mechanisms associated with its use as the sole treatment in animal models, delaying our understanding of anti-CD154 blockade-mediated immune tolerance. The purpose of this study was to investigate the mechanism underlying the anti-CD154 monoclonal antibody (mAb) blockade in inducing immune tolerance using an intrahepatic murine allogeneic islet transplantation model. Allogeneic BALB/c AnHsd (BALB/c) islets were infused into the liver of diabetic C57BL/6 (B6) mice via the cecal vein. Anti-CD154 mAb (MR1) was administered on −1, 0, 1, 3, 5, and 7 d posttransplantation at 0.5 mg per mouse. We showed that short-term MR1 monotherapy could prolong the allogeneic islet grafts to more than 250 d in the murine intrahepatic islet transplantation model. The second islet grafts transplanted under the kidney capsule of the recipients were protected from rejection. We also found that rejection of same-donor skin grafts transplanted to the tolerant mice was modestly delayed. Using a DEREG mouse model, FoxP3+ regulatory T (Treg) cells were shown to play important roles in transplantation tolerance. In mixed lymphocyte reactions, Treg cells from the tolerant mice showed more potency in suppressing BALB/c splenocyte-stimulated Teff cell proliferation than those from naïve mice. In this study, we demonstrated for the first time that a short-term anti-CD154 mAb single treatment could induce FoxP3+ Treg cell-mediated immune tolerance in the intrahepatic murine allogeneic islet transplantation model.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2089-2089
Author(s):  
Xiaofei Ni ◽  
Lingjun Wang ◽  
Tianshu Yu ◽  
Haoyi Wang ◽  
Yu Hou ◽  
...  

Abstract Low-dose decitabine modulates myeloid-derived suppressor cell function and restores immune tolerance in immune thrombocytopenia Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized with increased risk of bleeding. Myeloid-derived suppressor cells (MDSCs) are heterogeneous immature cells and natural inhibitors of adaptive immunity. Metabolic changes within MDSCs elucidate a direct influence on immunologic consequences of their suppressive activity. Liver kinase B1 (LKB1) is a tumor suppressor gene of STK11/LKB1 coding serine/Sue, and LKB1 signaling pathway plays an important role as a "bridge" between metabolic balance and functional homeostasis of immune cells. Our previous studies demonstrated that low dose decitabine, a hypomethylating agent, significantly increased the number of mature polyploidy megakaryocytes and exhibited long-term clinical efficacy. Besides, it also increased the production of Treg and enhanced their immunosuppressive function in ITP. However, whether decitabine could regulate the metabolic and suppressive activity of MDSCs in ITP is unknown. The percentage of MDSCs in peripheral blood mononuclear cells (PBMCs) was determined by flow cytometry, which was shown to be significantly lower in ITP compared with that in healthy controls. We then investigated the effect of low-dose decitabine in patients with active ITP, where decitabine induced a significant expansion of MDSCs in line with an impressive platelet response. In the in vitro experiments, MDSCs were isolated from PBMCs of ITP patients or healthy controls and cultured with different concentrations of decitabine (0/10nM/50nM/100 nM/1uM/10μM) for 7 days. A concentration gradient from 50nM to 1uM stimulated MDSCs amplification in a dose-dependent manner, and we chose an optimal concentration of 100 nM. Moreover, we found the mRNA expression level of LKB1, AMPKα1, AMPKα2, AMPKβ1, AMPKβ2, AMPKγ1, and AMPKγ2 was significantly lower in ITP patients than that in healthy control subjects. After incubation with decitabine (100nM), the relative expression of the above molecules were significantly increased compared to untreated levels. We also analyzed oxygen consumption rate (OCR) and key parameters of mitochondrial function within MDSCs. Overall, the OCR curve of ITP patients was lower than that of the healthy control subjects, and the OCR curve of ITP patients significantly improved after treatment with decitabine. We sorted the cultured MDSCs and co-cultured them with CFSE-labeled CD4 +CD25 - T cells to evaluate the suppressive activity of MDSCs. Results indicated that the inhibitory function of decitabine-modulated MDSCs was corrected in line with metabolic rewriting. We further established the ITP murine model by transferring splenocytes of C57BL/6 CD61 knockout mice, immunized against platelets from wild-type syngeneic C57BL/6 mice, into severe combined immune deficient (SCID) mice. MDSCs were sorted from the bone marrow of wild-type mice and incubated with PBS or decitabine, respectively. SCID mice were divided into three groups and received the same numbers of splenocyte transfer, two groups were given additional transfer of PBS-treated or decitabine-treated MDSCs. Our data showed that the decitaine-treated MDSCs group had significantly higher platelet counts compared with control group and PBS-treated MDSCs group. In summary, our findings suggest that the immune function and metabolic characteristics of MDSCs in ITP patients are impaired. These data shed new light on the molecular mechanism of decitabine action by regulating immune function and aerobic metabolism via LKB1, which supervises the immunosuppressive functions of MDSCs. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2019 ◽  
Vol 133 (7) ◽  
pp. 730-742 ◽  
Author(s):  
Hong-yu Zhao ◽  
Ya-hui Ma ◽  
Da-qi Li ◽  
Tao Sun ◽  
Li-zhen Li ◽  
...  

Abstract Increased macrophage phagocytosis of antibody-coated platelets, as well as decreased numbers and/or impaired function of CD4+CD25+Foxp3+ regulatory T (Treg) cells, has been shown to participate in the pathogenesis of immune thrombocytopenia (ITP). Low-dose histone deacetylase inhibitors (HDACi’s) are anti-inflammatory and immunomodulatory agents that can enhance immunosuppression in graft-versus-host disease by increasing the number and function of Foxp3+ Treg cells, but it is unclear whether they have the potential to promote immune tolerance and platelet release in ITP. In this study, we performed in vitro and in vivo experiments and found that a low-dose HDACi (chidamide) alleviated thrombocytopenia in passive and active murine models of ITP. Further, low-dose HDACi’s attenuated macrophage phagocytosis of antibody-coated platelets, stimulated the production of natural Foxp3+ Treg cells, promoted the peripheral conversion of T cells into Treg cells, and restored Treg cell suppression in vivo and in vitro. Finally, we confirmed that low-dose HDACi’s could regulate CTLA4 expression in peripheral blood mononuclear cells through modulation of histone H3K27 acetylation. Low-dose HDACi treatment in ITP could be offset by blocking the effect of CTLA4. Therefore, we propose that low-dose chidamide administration has potential as a novel treatment for ITP in the clinic.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3117
Author(s):  
Izabela Gregorczyk ◽  
Agnieszka Jasiecka-Mikołajczyk ◽  
Tomasz Maślanka

The main purpose of this study was to investigate whether the blockade of the interaction between the receptor activator of nuclear factor-κB (NF-ĸB) ligand (RANKL) and its receptor RANK as well as the blockade of NF-κB inhibitor kinase (IKK) and of NF-κB translocation have the potential to suppress the pathogenesis of allergic asthma by inhibition and/or enhancement of the production by CD4+ and CD8+ T cells of important cytokines promoting (i.e., IL-4 and IL-17) and/or inhibiting (i.e., IL-10 and TGF-β), respectively, the development of allergic asthma. Studies using ovalbumin(OVA)-immunized mice have demonstrated that all the tested therapeutic strategies prevented the OVA-induced increase in the absolute number of IL-4- and IL-17-producing CD4+ T cells (i.e., Th2 and Th17 cells, respectively) indirectly, i.e., through the inhibition of the clonal expansion of these cells in the mediastinal lymph nodes. Additionally, the blockade of NF-κB translocation and RANKL/RANK interaction, but not IKK, prevented the OVA-induced increase in the percentage of IL-4-, IL-10- and IL-17-producing CD4+ T cells. These latter results strongly suggest that both therapeutic strategies can directly decrease IL-4 and IL-17 production by Th2 and Th17 cells, respectively. This action may constitute an important mechanism underlying the anti-asthmatic effect induced by the blockade of NF-κB translocation and of RANKL/RANK interaction. Thus, in this context, both these therapeutic strategies seem to have an advantage over the blockade of IKK. None of the tested therapeutic strategies increased both the absolute number and frequency of IL-10- and TGF-β-producing Treg cells, and hence they lacked the potential to inhibit the development of the disease via this mechanism.


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