scholarly journals Aspirin Attenuates Cardiac Allograft Rejection by Inhibiting the Maturation of Dendritic Cells via the NF-κB Signaling Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Xi Zhang ◽  
Aie Chang ◽  
Yanqiang Zou ◽  
Heng Xu ◽  
Jikai Cui ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Dendritic Cells ◽  
Signaling Pathway ◽  
Inflammatory Cytokines ◽  
Allograft Rejection ◽  
Cardiac Allograft ◽  
Cardiac Allograft Rejection ◽  
Pro Inflammatory Cytokines

Background: Dendritic cells (DCs) serve as an important part of the immune system and play a dual role in immune response. Mature DCs can initiate immune response, while immature or semi-mature DCs induce immune hyporesponsiveness or tolerance. Previous studies have shown that aspirin can effectively inhibit the maturation of DCs. However, the protective effect of aspirin on acute cardiac allograft rejection has not been studied. The aim of this study was to elucidate the effect of aspirin exert on allograft rejection.Methods: The model of MHC-mismatched (BALB/c to B6 mice) heterotopic heart transplantation was established and administered intraperitoneal injection with aspirin. The severity of allograft rejection, transcriptional levels of cytokines, and characteristics of immune cells were assessed. Bone marrow-derived dendritic cells (BMDCs) were generated with or without aspirin. The function of DCs was determined via mixed lymphocyte reaction (MLR). The signaling pathway of DCs was detected by Western blotting.Results: Aspirin significantly prolonged the survival of cardiac allograft in mouse, inhibited the production of pro-inflammatory cytokines and the differentiation of effector T cells (Th1 and Th17), as well as promoted the regulatory T cells (Treg). The maturation of DCs in the spleen was obviously suppressed with aspirin treatment. In vitro, aspirin decreased the activation of NF-κB signaling of DCs, as well as impeded MHCII and co-stimulatory molecules (CD80, CD86, and CD40) expression on DCs. Moreover, both the pro-inflammatory cytokines and function of DCs were suppressed by aspirin.Conclusion: Aspirin inhibits the maturation of DCs through the NF-κB signaling pathway and attenuates acute cardiac allograft rejection.

scholarly journals Apoptotic Cells for the Prevention of Cytokine Release Syndrome (CRS) in CAR T-Cell Therapy

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1626-1626
Author(s):  
Dror Mevorach ◽  
Veronique Amor ◽  
Yehudith Shabat
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Inflammatory Cytokines ◽  
Apoptotic Cells ◽  
Car T ◽  
Ifn Γ ◽  
Pro Inflammatory Cytokines

Abstract Background: Chimeric antigen receptor (CAR)-modified T cells with specificity against CD19 have demonstrated dramatic promise against highly refractory hematologic malignancies. Clinical responses with complete remission rates as high as 90% have been reported in children and adults with relapsed/refractory acute lymphoblastic leukemia (ALL). However, very significant toxicity has been observed and as many as 30% in average developing severe forms of CRS and possibly related neurotoxicity. CRS is occurring due to large secretion of pro-inflammatory cytokines, mainly from macrophages/monocytes, and resembles macrophage-activating syndrome and hemophagocytosis in response to CAR T-secreting IFN-g and possibly additional cytokines. To better understand the mechanisms leading to CRS and to treat or prevent it, we have developed in vitro and in vivo models of CRS with and without CAR-modified T cells. Early apoptotic cells that have been successfully tested for the prevention of acute GVHD, including in 7 ALL patients, were tested in these models for their effect on cytokines and CAR T cell cytotoxicity. Methods: CD19-expressing HeLa cells were used alone or with co-incubation with human macrophages for in vitro experiments and intraperitoneal experiments. Raji was used in vivo for leukemia induction. LPS and IFN-γ were used to trigger additional cytokine release. CD19-specific CAR-modified cells were used (ProMab) for anti-tumor effect against CD19-bearing cells. Cytotoxicity assay was examined in vivo using 7-AAD with flow cytometry and in vitro by survival curves and analysis of tumor load in bone marrow and liver. CRS occurred spontaneously or in response to LPS and IFN-γ. Mouse IL-10, IL-1β, IL-2, IP-10, IL-4, IL-5, IL-6, IFNα, IL-9, IL-13, IFN-γ, IL-12p70, GM-CSF, TNF-α, MIP-1α, MIP-1β, IL-17A, IL-15/IL-15R, and IL-7, as well as 32 human cytokines were evaluated by Luminex technology using the MAPIX system analyzer (Mereck Millipore) and MILLIPLEX Analyst software (Merek Millipore). Mouse IL-6Rα, MIG (CXCL9), and TGF-β1 were evaluated by Quantikine ELISA (R&D systems). Bone marrow and liver were evaluated using flow cytometry and immunohistochemistry. The IFN-γ effect was evaluated by STAT1 phosphorylation and biological products. Human macrophages and dendritic cells were generated from monocytes. Early apoptotic cells were produced as shown in GVHD clinical trial; at least 50% of cells were annexin V-positive and less than 5% were PI-positive. Results: Apoptotic cells had no negative effect in vitro or in vivo on CAR-modified T cells with specificity against CD19. There were comparable E/T ratios for CAR T in the presence or absence of apoptotic cells in vitro, and comparable survival curves in vivo. On the other hand, significant downregulation (p<0.01) of pro-inflammatory cytokines, including IL-6, IP-10, TNF-a, MIP-1α, MIP-1β, was documented. IFN-γ was not downregulated, but its effect on macrophages and dendritic cells was inhibited at the level of phosphorylated STAT1 and IFN-γ-induced expression of CXCL10 and CXCL9 was reduced. Conclusion: CRS evolves from several factors, including tumor biology, interaction with monocytes/macrophages/dendritic cells, and as a response to the CAR T cell effect and expansion. Apoptotic cells decrease pro-inflammatory cytokines that originate from innate immunity and inhibit the IFN-γ effect on monocyte/macrophages/ dendritic cells without harming IFN-γ levels or CAR-T cytotoxicity. Disclosures Mevorach: Enlivex: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Amor:Enlivex: Employment. Shabat:Enlivex: Employment.

Human CD4+ CD25high Regulatory T Cells Inhibit Myeloid but Not Plasmacytoid Dendritic Cells Activation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 767-767
Author(s):  
Roch Houot ◽  
Ivan Perrot ◽  
Isabelle Durand ◽  
Eric Garcia ◽  
Serge Lebecque
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Regulatory T Cells ◽  
Inflammatory Cytokines ◽  
Human Peripheral Blood ◽  
Cell Contact ◽  
Cytokines Secretion ◽  
Pro Inflammatory Cytokines

Abstract CD4+CD25+ regulatory T cells (Treg) are essential negative regulators of immune responses. However, the mechanisms of immune suppression and the spectrum of cells they target remain incompletely defined. In particular, although Treg directly suppress conventional T cells in vitro, they might also affect antigen presenting cells (APC). Here, we studied the maturation of human myeloid (mDC) and plasmacytoid (pDC) dendritic cells activated with Toll-like receptor (TLR) ligands in the presence of CD4+ CD25high regulatory T cells in vitro. T cells and DC subsets were purified from normal human peripheral blood. LPS, CpG ODN 2216 and R-848 were used to trigger the maturation of mDC, pDC or both through TLR4, TLR9 and TLR7/8 respectively. Preactivated CD4+ CD25high Treg had no effect on the maturation of pDC. Conversely, they strongly suppressed TLR-triggered mDC costimulatory molecules up-regulation, pro-inflammatory cytokines secretion and their antigen presentation capacity, as opposed to conventionnal T cells (Tconv). At a ratio of 3 Treg for 1 DC, the percentage of mDC acquiring CD80 was reduced 5 fold (from 75% to 16%) while the Mean Fluorescence Intensity was decreased by approximately 65% for CD80 and 35% for CD86 after LPS stimulation and by 50% and 20% after R-848 stimulation. Furthermore, Treg dramatically decreased the secretion of IL-12p40, TNF-α, and IL-6 by mDC (95%, 93% and 50% average inhibition respectively) after LPS activation and to a lesser but still significant extent (38%, 35%, and 38% average inhibition respectively) after R848 stimulation. Finally, we found that Treg-conditionned mDC had a reduced ability to trigger naïve T cell proliferation in a mixed leukocyte reaction. Suppression of mDC activation by Treg appeared to require cell-cell contact. Moreover, the inhibition of pro-inflammatory cytokines secretion, but not of phenotypic maturation, was almost completely restored using an anti-IL10 receptor monoclonal antibody, but not anti-TGFβ nor anti-CTLA-4 blocking antibodies. Those data suggest that Treg prevent the co-stimulatory molecules up-regulation on mDC through contact dependent mechanisms, while the modulation of cytokines secretion appears to be largely mediated by IL-10. Overall, our results provide the first evidence of a direct inhibition of human mDC but not pDC maturation by CD4+ CD25high Treg. Therefore, by restraining the maturation of mDC, human Treg may enlist those cells for the initiation and the amplification of tolerance in vivo.

scholarly journals Role of cholinergic anti-inflammatory pathway in protecting sepsis-induced acute lung injury through regulation of the dendritic cells

2021 ◽  
Author(s):  
Ruiting Li ◽  
Xuemei Hu ◽  
Huibin Chen ◽  
Yin Yuan ◽  
Huiling Guo ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Inflammatory Response ◽  
Inflammatory Cytokines ◽  
Mice Model ◽  
Pro Inflammatory Cytokines

Abstract Background The cholinergic anti-inflammatory pathway (CAP) connects the immune response system and the nervous system via the vagus nerve. The key regulatory receptor is the α7-subtype of the nicotinic acetylcholine receptor (α7nAChR), which is localized on the surface of the cells of immune system. CAP has been proved to be effective in suppressing the inflammation responses in acute lung injury (ALI). Dendritic cells (DCs), the important antigen-presenting cells (APCs), also express the α7nAChR. They not only play an important role in immune response priming but also in participating in the pathological process of ALI. Past studies have indicated that reducing the quantity of mature conventional DCs (cDCs) and inhibiting the maturation of pulmonary DCs may prove effective for the treatment of ALI. However, the effects of CAP on maturation, function and quantity of DCs and cDCs in ALI remain unclear. Objective It was hypothesized that the activation of CAP may inhibit the inflammatory response of ALI by regulating maturation, phenotype, and quantity of DCs and cDCs. This can be considered as an important intervention strategy for treating ALI. Methods GTS-21 (GTS-21 dihydrochloride), an α7nAchR agonist was administered in sepsis-induced ALI mice model and LPS-primed bone marrow-derived dendritic cells (BMDCs). The effects of GTS-21 were observed with respect to maturation, phenotype, and quantity of DCs, cDCs, and cDCs2 (type 2 cDCs), and the release of DC-related pro-inflammatory cytokines (such as IL-6, TNF-α, IL-18 IL-1β, IL-12p40, and HMGB1) in vivo and in vitro conditions. Results The results of the present study revealed that, GTS-21 treatment regulated the maturation of DCs and the production of DC-related pro-inflammatory cytokines in vitro and in sepsis-induced ALI mice model, it reduced the quantity of CD11c+MHCII+ cDCs and CD11c+CD11b+ cDCs2 in vivo experiment. Conclusions The activation of CAP contributes to the reduction in the inflammatory response in ALI by regulating maturation, phenotype, and quantity of DCs, cDCs, and cDCs2.

scholarly journals Extracellular vesicles from human cardiovascular progenitors trigger a reparative immune response in infarcted hearts

2020 ◽  
Author(s):  
Bruna Lima Correa ◽  
Nadia El Harane ◽  
Ingrid Gomez ◽  
Hocine Rachid Hocine ◽  
José Vilar ◽  
...  
Keyword(s):  
Immune Response ◽  
Extracellular Vesicles ◽  
Inflammatory Cytokines ◽  
Nk Cell ◽  
Inflammatory Monocytes ◽  
Ifn Γ ◽  
Anti Inflammatory ◽  
Pro Inflammatory Cytokines

Abstract Aims The cardioprotective effects of human induced pluripotent stem cell-derived cardiovascular progenitor cells (CPC) are largely mediated by the paracrine release of extracellular vesicles (EV). We aimed to assess the immunological behaviour of EV-CPC, which is a prerequisite for their clinical translation. Methods and results Flow cytometry demonstrated that EV-CPC expressed very low levels of immune relevant molecules including HLA Class I, CD80, CD274 (PD-L1), and CD275 (ICOS-L); and moderate levels of ligands of the natural killer (NK) cell activating receptor, NKG2D. In mixed lymphocyte reactions, EV-CPC neither induced nor modulated adaptive allogeneic T cell immune responses. They also failed to induce NK cell degranulation, even at high concentrations. These in vitro effects were confirmed in vivo as repeated injections of EV-CPC did not stimulate production of immunoglobulins or affect the interferon (IFN)-γ responses from primed splenocytes. In a mouse model of chronic heart failure, intra-myocardial injections of EV-CPC, 3 weeks after myocardial infarction, decreased both the number of cardiac pro-inflammatory Ly6Chigh monocytes and circulating levels of pro-inflammatory cytokines (IL-1α, TNF-α, and IFN-γ). In a model of acute infarction, direct cardiac injection of EV-CPC 2 days after infarction reduced pro-inflammatory macrophages, Ly6Chigh monocytes, and neutrophils in heart tissue as compared to controls. EV-CPC also reduced levels of pro-inflammatory cytokines IL-1α, IL-2, and IL-6, and increased levels of the anti-inflammatory cytokine IL-10. These effects on human macrophages and monocytes were reproduced in vitro; EV-CPC reduced the number of pro-inflammatory monocytes and M1 macrophages, while increasing the number of anti-inflammatory M2 macrophages. Conclusions EV-CPC do not trigger an immune response either in in vitro human allogeneic models or in immunocompetent animal models. The capacity for orienting the response of monocyte/macrophages towards resolution of inflammation strengthens the clinical attractiveness of EV-CPC as an acellular therapy for cardiac repair.

P761The effect of extracorporeal photopheresis on cardiac allograft rejection and on lymphocyte subclasses

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
T Teszak ◽  
A Assabiny ◽  
A Kiraly ◽  
Z Tarjanyi ◽  
N Parazs ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
B Lymphocytes ◽  
Heart Transplant ◽  
Allograft Rejection ◽  
Cytotoxic T Cells ◽  
Cardiac Allograft ◽  
Extracorporeal Photopheresis ◽  
Cardiac Allograft Rejection ◽  
Cellular Rejection

Abstract Background Cardiac allograft rejection is known to have a profound impact on graft survival and mortality after heart transplant. Previous data on the efficacy of extracorporeal photopheresis (ECP) in the management of cardiac allograft rejection is encouraging. Though, clear evidence on the exact indication and data regarding its effect on distinct lymphocyte subtypes are still lacking. Based on their cytokine production, both helper and cytotoxic T cells can differentiate into either regulatory cells participating in the suppression of rejection or into effector cells responsible for its maintenance. Regulatory T cells are essential for the termination of rejection, while B lymphocytes and natural killer (NK) cells contribute to it. Purpose We aimed to investigate the anti-rejection efficacy and the impact of ECP on peripheral blood lymphocyte subclasses in adult heart transplant recipients. Methods In a retrospective analysis of 12 consecutive patients treated with ECP for cardiac allograft rejection between 2013 and 2019, we examined the grade of rejection in endomyocardial biopsies (EMB) based on the International Society for Heart and Lung Transplantation classification. We analysed the absolute counts and the percentages of helper, cytotoxic and regulatory T cells, B lymphocytes and NK cells with fluorescence activated cell sorting. Measurements were performed both before and after the ECP treatment period. Data values were given as either mean±standard deviation or median [min–max]. Results The patients underwent 26 [2–39] ECP treatments in addition to standard immunosuppressant therapy. Whereas grade 2R cellular rejection was detected in 83% of the cases prior to initiating ECP, none of the examined EMB specimen revealed rejection greater than grade 1R cellular rejection post ECP therapy. The average grade of cellular rejection improved significantly (1.25±0.45 vs. 0.50±0.53; p=0.022). The absolute count and the percentage of helper T cells increased significantly post ECP therapy (0.34 G/l±0.26 G/l vs. 0.51 G/l±0.39 G/l; p=0.018 and 3.43%±2.24% vs. 5.98%±3.64%; p=0.017, respectively). There was also a significant rise in the percentage of cytotoxic T cells (2.33%±1.46% vs. 4.16±2.98%; p=0.027). We noticed an almost significant twofold increase in the percentage of regulatory T cells on completion of the ECP therapy (0.20%±0.22% vs. 0.37%±0.20%; p=0.060). Neither B lymphocyte nor NK cell counts revealed any significant changes. Conclusion ECP was effective in reducing the severity of cardiac allograft rejection episodes. The significant decrease in rejection rates might be indicative of the predominance of anti-inflammatory helper and cytotoxic T cell subpopulations and the increase of regulatory T cell count post ECP therapy. However, discussion of the results are limited by small sample size and the effect of medical therapy on the lymphocytes.

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