Curcumin attenuates acute graft-versus-host disease severity via in vivo regulations on Th1, Th17 and regulatory T cells

Defining the mechanisms behind the hepatoprotective properties of curcumin

As a critical cause of human dysfunctionality, hepatic failure leads to approximately two million deaths per year and is on the rise. Considering multiple inflammatory, oxidative, and apoptotic mechanisms behind hepatotoxicity, it urges the need for finding novel multi-targeting agents. Curcumin is a phenolic compound with anti-inflammatory, antioxidant, and anti-apoptotic roles. Curcumin possesses auspicious health benefits and protects against several diseases with exceptional safety and tolerability. This review focused on the hepatoprotective mechanisms of curcumin. The need to develop novel delivery systems of curcumin (e.g., nanoparticles, self-micro emulsifying, lipid-based colloids, solid lipid nanoparticles, cyclodextrin inclusion, phospholipid complexes, and nanoemulsions) is also considered.

Curcumin as a regulator of Th17 cells: Unveiling the mechanisms

Curcumin, a polyphenol natural product derived from turmeric, possesses diverse pharmacological effects due to its interactions with various cells and molecules. Recent studies have highlighted its immunomodulatory properties, including its impact on immune cells and mediators involved in immune responses. Th17 cells play a crucial role in promoting immune responses against extracellular pathogens by recruiting neutrophils and inducing inflammation. These cells produce inflammatory cytokines such as TNF-α, IL-21, IL-17A, IL-23, IL-17F, IL-22, and IL-26. Curcumin has been shown to significantly inhibit the proliferation of Th17 cells and reduce the production of inflammatory cytokines, including TNF-α, IL-22, and IL-17. This review aims to assess the effectiveness of curcumin and its underlying mechanisms in modulating Th17 cells.

Mitochondrial-targeted curcumin inhibits T-cell activation via Nrf2 and inhibits graft-versus-host-disease in a mouse model

Anti-inflammatory and immune suppressive agents are required to moderate hyper-activation of lymphocytes under disease conditions or organ transplantation. However, selective disruption of mitochondrial redox has not been evaluated as a therapeutic strategy for suppression of T-cell-mediated pathologies. Using mitochondrial targeted curcumin (MitoC), we studied the effect of mitochondrial redox modulation on T-cell responses by flow cytometry, transmission electron microscopy, transcriptomics, and proteomics, and the role of Nrf2 was studied using Nrf2- /- mice. MitoC decreased mitochondrial TrxR activity, enhanced mitochondrial ROS (mROS) production, depleted mitochondrial glutathione, and suppressed activation-induced increase in mitochondrial biomass. This led to suppression of T-cell responses and metabolic reprogramming towards Treg differentiation. MitoC induced nuclear translocation and DNA binding of Nrf2, leading to upregulation of Nrf2-dependent genes and proteins. MitoC-mediated changes in mitochondrial redox and modulation of T-cell responses are abolished in Nrf2- /- mice. Restoration of mitochondrial thiols abrogated inhibition of T-cell responses. MitoC suppressed alloantigen-induced lymphoblast formation, inflammatory cytokines, morbidity, and mortality in acute graft-versus-host disease mice. Disruption of mitochondrial thiols but not mROS increase inculcates an Nrf2-dependent immune-suppressive disposition in T cells for the propitious treatment of graft-versus-host disease.

Withania Somnifera Extract Mitigates Experimental Acute Graft versus Host Disease Without Abrogating Graft Versus Leukemia Effect

Acute graft versus host disease (aGvHD) is the major contributor of nonrelapse mortality in alloHSCT. It is associated with an inflammatory immune response manifesting as cytokine storm with ensuing damage to target organs such as liver, gut, and skin. Prevention of aGvHD while retaining the beneficial graft versus leukemia (GvL) effect remains a major challenge. Withania somnifera extract (WSE) is known for its anti-inflammatory, immune-modulatory, and anticancer properties, which are appealing in the context of aGvHD. Herein, we demonstrated that prophylactic and therapeutic use of WSE in experimental model of alloHSCT mitigates aGvHD-associated morbidity and mortality. In the prophylaxis study, a dose of 75 mg/kg of WSE offered greatest protection against death due to aGvHD (hazard ratio [HR] = 0.15 [0.03-0.68], P ≤ .01), whereas 250 mg/kg was most effective for the treatment of aGvHD (HR = 0.16 [0.05-0.5], P ≤ .01). WSE treatment protected liver, gut, and skin from damage by inhibiting cytokine storm and lymphocytic infiltration to aGvHD target organs. In addition, WSE did not compromise the GvL effect, as alloHSCT with or without WSE did not allow the leukemic A20 cells to grow. In fact, WSE showed marginal antileukemic effect in vivo. WSE is currently under clinical investigation for the prevention and treatment of aGvHD.

Dissecting the regulatory network of transcription factors in T cell phenotype/functioning during GVHD and GVT

Transcription factors play a major role in regulation and orchestration of immune responses. The immunological context of the response can alter the regulatory networks required for proper functioning. While these networks have been well-studied in canonical immune contexts like infection, the transcription factor landscape during alloactivation remains unclear. This review addresses how transcription factors contribute to the functioning of mature alloactivated T cells. This review will also examine how these factors form a regulatory network to control alloresponses, with a focus specifically on those factors expressed by and controlling activity of T cells of the various subsets involved in graft-versus-host disease (GVHD) and graft-versus-tumor (GVT) responses.

Small heterodimer partner interacting leucine zipper protein (SMILE) ameliorates autoimmune arthritis via AMPK signaling pathway and the regulation of B cell activation

Rheumatoid arthritis (RA) is an autoimmune disease that causes joint swelling and inflammation and can involve the entire body. RA is characterized by the increase of pro-inflammatory cytokines such as interleukin (IL) and tumor necrosis factor, and the over-activation of T lymphocytes and B lymphocytes, which may lead to severe chronic inflammation of joints. However, despite numerous studies the pathogenesis and treatment of RA remain unresolved. This study investigated the use of small heterodimer partner-interacting leucine zipper protein (SMILE) overexpression to treat a mouse model of RA. SMILE is an insulin-inducible corepressor through adenosine monophosphate-activated kinase (AMPK) signaling pathway. The injection of a SMILE overexpression vector to mice with collagen induced-arthritis resulted in a milder clinical pathology and a reduced incidence of arthritis, less joint tissue damage, and lower levels of Th17 cells and plasma B cells in the spleen. Immunohistochemistry of the joint tissue showed that SMILE decreased B-cell activating factor (BAFF) receptor (BAFF-R), mTOR, and STAT3 expression but increased AMPK expression. In SMILE-overexpressing transgenic mice with collagen antibody-induced arthritis (CAIA), a decrease in the arthritis score and reductions in tissue damage, the number of B cells, and antibody production were observed. The treatment of immune cells in vitro with curcumin, a known SMILE-inducing agent, led to decreases in plasma B cells, germinal center B cells, IL-17-producing B cells, and BAFF-R-positive B cells. Taken together, our findings demonstrate the therapeutic potential of SMILE in RA, based on its inhibition of B cell activation mediated by the AMPK/mTOR and STAT3 signaling pathway and BAFF-R expression. Video abstract.

Effects of nanocurcumin supplementation on T-helper 17 cells inflammatory response in patients with Behcet's disease: a randomized controlled trial

OBJECTIVE

Present research was performed to assess the effects of nanocurcumin supplementation on T-helper 17 (Th17) cells inflammatory response in patients with Behcet's disease (BD).

METHODS

In this randomized double-blind, placebo-controlled trial, 36 BD subjects were randomly placed into two groups to take 80 mg/day nanocurcumin or placebo for eight weeks. Disease activity, frequency of Th17 cells and expression of related parameters including retinoic acid-related orphan receptor γ (RORγt) transcription factor messenger RNA (mRNA), related microRNAs (miRNAs) such as miRNA-155, miRNA-181, and miRNA-326 as well as proinflammatory cytokines including interleukin (IL)-17 and IL-23 were evaluated.

RESULTS

Thirty-two patients (17 in the nanocurcumin and 15 in the placebo groups) completed the trial. Number of Th17 cells decreased significantly in the nanocurcumin group compared to baseline (p = .012) and placebo (p = .047). Moreover, RORγt, IL-17, IL-23, miRNA-155, miRNA-181, and miRNA-326 mRNA expression decreased significantly in the nanocurcumin group compared with baseline (p = .004, p = .009, p < .001, p < .001, p < .001, p < .001, respectively) and placebo (p = .002, p = .021, p = .006, p = .035, p < .001, p = .017, respectively). Significant reductions in IL-17 and IL-23 were seen in nanocurcumin group compared with baseline (p = .017 and p = .015) and placebo (p = .047 and p = .048, respectively). Significant reduction in disease activity was observed in nanocurcumin group compared with placebo group (p = .035).

CONCLUSION

Nanocurcumin supplementation had favorable effects in improving inflammatory factors and disease activity in BD patients. Additional studies are warranted to suggest nanocurcumin as a safe complementary therapy in BD.HighlightsNanocurcumin supplementation decreased Th17 cells frequency significantly compared with baseline and placebo group.Nanocurcumin supplementation decreased mRNA expression of RORγt, IL-17, IL-23, miRNA-155, miRNA-181, and miRNA-326 significantly compared to baseline and placebo group.Nanocurcumin supplementation decreased cell supernatant IL-17 and IL-23 significantly compared to baseline and placebo group.Nanocurcumin supplementation decreased disease activity significantly compared to placebo group.

Nanocurcumin supplementation ameliorates Behcet's disease by modulating regulatory T cells: A randomized, double-blind, placebo-controlled trial

Current research was designed to assess the effects of nanocurcumin supplementation on regulatory T (Treg) cells frequency and function in Behçet's disease (BD). In this randomized double-masked, placebo-controlled trial, 36 BD subjects were randomly put into two groups to take one 80 mg nanocurcumin capsule or placebo daily for 8 weeks. Before and after trial, disease activity, Treg cells frequency and expression of related immunologic parameters including forkhead box protein P3 (Foxp3) transcription factor messenger RNA (mRNA) and microRNAs (miRNAs) such as miRNA-25 and miRNA-106b as well as cytokines including transforming growth factor (TGF)-β and interleukin (IL)-10 were studied. Thirty-two patients (17 in the nanocurcumin and 15 in the placebo groups) completed the trial. Treg cells frequency increased significantly in the nanocurcumin group compared with baseline (P < 0.001) and placebo group (P < 0.001). Moreover, FoxP3, TGF-β, IL-10, miRNA-25, and miRNA-106b mRNA expression levels increased considerably in the nanocurcumin group compared to baseline (P < 0.001) and placebo group (P < 0.001, P < 0.001, P = 0.025, P = 0.011, and P < 0.001, respectively). Significant increases in serum TGF-β and IL-10 were seen in nanocurcumin group compared with baseline (P < 0.001) and placebo group (P = 0.001 and P < 0.001, respectively). Significant decrease in disease activity was found in nanocurcumin group compared with placebo group (P = 0.044). Our study provided a promising view for desirable effects of nanocurcumin supplementation in improving immunological parameters and disease activity in BD.

Immunomodulatory Effects of Curcumin in Rheumatoid Arthritis: Evidence from Molecular Mechanisms to Clinical Outcomes

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disorder characterized by the destruction of the joint and bone resorption. The production of pro-inflammatory cytokines and chemokines, dysregulated functions of three important subtypes of T helper (T_H) cells including T_H1, T_H17, and regulator T (Treg) cells are major causes of the initiation and development of RA. Moreover, B cells as a source of the production of several autoantibodies play key roles in the pathogenesis of RA. The last decades have seen increasingly rapid advances in the field of immunopharmacology using natural origin compounds for the management of various inflammatory diseases. Curcumin, a main active polyphenol compound isolated from turmeric, curcuma longa, possesses a wide range of pharmacologic properties for the treatment of several diseases. This review comprehensively will assess beneficial immunomodulatory effects of curcumin on the production of pro-inflammatory cytokines and also dysregulated functions of immune cells including T_H1, T_H17, Treg, and B cells in RA. We also seek the clinical efficacy of curcumin for the treatment of RA in several recent clinical trials. In conclusion, curcumin has been found to ameliorate RA complications through modulating inflammatory and autoreactive responses in immune cells and synovial fibroblast cells via inhibiting the expression or function of pro-inflammatory mediators, such as nuclear factor-κB (NF-κB), activated protein-1 (AP-1), and mitogen-activated protein kinases (MAPKs). Of note, curcumin treatment without any adverse effects can attenuate the clinical symptoms of RA patients and, therefore, has therapeutic potential for the treatment of the diseases.

Revisiting Traumatic Brain Injury: From Molecular Mechanisms to Therapeutic Interventions

Studying the complex molecular mechanisms involved in traumatic brain injury (TBI) is crucial for developing new therapies for TBI. Current treatments for TBI are primarily focused on patient stabilization and symptom mitigation. However, the field lacks defined therapies to prevent cell death, oxidative stress, and inflammatory cascades which lead to chronic pathology. Little can be done to treat the mechanical damage that occurs during the primary insult of a TBI; however, secondary injury mechanisms, such as inflammation, blood-brain barrier (BBB) breakdown, edema formation, excitotoxicity, oxidative stress, and cell death, can be targeted by therapeutic interventions. Elucidating the many mechanisms underlying secondary injury and studying targets of neuroprotective therapeutic agents is critical for developing new treatments. Therefore, we present a review on the molecular events following TBI from inflammation to programmed cell death and discuss current research and the latest therapeutic strategies to help understand TBI-mediated secondary injury.

Prevention of acute graft-versus-host-disease by Withaferin a via suppression of AKT/mTOR pathway

Acute Graft versus Host Disease (aGVHD) is a frequent and serious complication in patients receiving allogeneic bone marrow transplantation (allo-BMT) and often requires rigorous prophylaxis. The current treatment regimens for aGVHD are associated with several side effects which necessitates the development of novel interventions that prevent aGVHD without precluding graft-versus-tumor effects. In the present study, we show that treatment of donor graft with plant steroidal lactone Withaferin A (WA) prior to transplantation markedly reduced aGVHD mediated damage in target organs without compromising the graft-versus.-tumor activity of the transplanted lymphocytes. WA abrogated post-transplant cytokine storm associated with allo-activation of donor lymphocytes. This was attributed to the ability of WA to inhibit early signaling events in T-cell activation including lymphoblast formation and activation of AKT/mTOR pathway. Mortality and morbidity related to allo-transplantation was significantly reduced in recipients of WA treated donor splenocytes compared to recipient of vehicle treated donor splenocytes. Further, WA treatment did not have any effect on reconstitution of lymphoid and myeloid lineages in recipients, resulting in stable and complete donor chimerism. In agreement with previous reports showing the effectiveness of WA in a mouse model of partial chimerism, our data further establishes that WA is able to attenuate aGVHD in an MHC-mismatched high dose chemo-conditioned murine model without compromising engraftment. This study provides compelling scientific basis for possible application of WA for prevention and treatment of aGVHD in patients receiving allo-BMT.

Chinese Medicine Treatment on Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation

Graft-versus-host disease (GVHD) is the most common complication after allogeneic hematopoietic stem cell transplantation, and also an important factor affecting the survival and quality of life in patients after transplantation. Currently, immunosuppressive therapy is commonly used for GVHD, but the curative effect is not ideal. How to effectively prevent and treat GVHD is one of the difficulties to be solved urgently in the field of transplantation. In this paper, we summarize the latest progress in pathogenesis, prevention and treatment of GVHD with Chinese medicine (CM). We hope it will provide ideas and methods for exploring the mechanism and establishing a new comprehensive therapy for GVHD with CM.

Downregulation of Interleukin- (IL-) 17 through Enhanced Indoleamine 2,3-Dioxygenase (IDO) Induction by Curcumin: A Potential Mechanism of Tolerance towards Helicobacter pylori

The anti-inflammatory and antimicrobial properties of curcumin suggest its use as an anti-Helicobacter pylori (H. pylori) agent, but mechanisms underlying its helpful activity are still not clear. Indoleamine 2,3-dioxygenase (IDO) promotes the effector T cell apoptosis by catalyzing the rate-limiting first step in tryptophan catabolism, and its high expression in H. pylori-infected human gastric mucosa attenuates Th1 and Th17 immune response. The aim of this study was to investigate the role of curcumin in modulating the expression of IL-17 and IDO in H. pylori-infected human gastric mucosa. In an organ culture chamber, gastric biopsies from 35 patients were treated with and without 200 μM curcumin. In H. pylori-infected patients (n = 21), IL-17 was significantly lower, both in gastric biopsies (p = 0.0003) and culture supernatant (p = 0.0001) while IDO significantly increased (p < 0.00001) in curcumin-treated sample compared with untreated samples. In a subgroup of H. pylori-infected patients (n = 15), samples treated with curcumin in addition to IDO inhibitor 1-methyl-L-tryptophan (1-MT) showed a higher expression of IL-17 compared with untreated samples and curcumin-treated alone (p < 0.00001). Curcumin downregulates IL-17 production through the induction of IDO in H. pylori-infected human gastric mucosa, suggesting its role in dampening H. pylori-induced immune-mediated inflammatory changes.

Chitinase 3-Like-1-Deficient Splenocytes Deteriorated the Pathogenesis of Acute Graft-Versus-Host Disease via Regulating Differentiation of Tfh Cells

Acute graft-versus-host disease (aGVHD) is an intractable complication in transplant patients, limiting the efficacy of this therapy. Chitinase 3-like-1 (CHI3L1), a member of the glycosyl hydrolase 18 family that lacks chitinase activity, plays a critical role in a variety of inflammatory diseases. Here, we investigated the in vitro and in vivo effects of CHI3L1 on the development of aGVHD. In this study, mixed lymphocyte reactions (MLR) in vitro showed that CHI3L1 deficiency in CD4⁺ T cell promoted the production of interferon (IFN)-γ and T follicular helper (Tfh)-related cytokines such as interleukin-6 (IL-6) and interleukin-21 (IL-21). Meanwhile, the inducible Tfh cell population increased remarkably in CHI3L1-KO CD4⁺ T cells' induction group, compared with WT group. Then, in the murine acute GVHD model, we found that CHI3L1 deficiency in donor splenocytes dramatically increased the severity of aGVHD through enhancing Tfh cell differentiation. Moreover, at mRNA and protein levels, we defined several molecules that may account for the enhanced ability of CHI3L1-KO splenocytes to migrate into target organs and produce IFN-γ and Tfh-related cytokines and chemokines, such as IL-6, IL-21, and CXCL13. Expression of inducible co-stimulator (ICOS) and B cell lymphoma 6 (Bcl6) increased in the skin, the intestine, the lung, and the liver from CHI3L1-KO splenocyte-treated aGVHD mice. Therefore, these results strongly imply that CHI3L1 levels in donor cells may be related to the risk of aGVHD and targeting CHI3L1 represents a novel therapeutic strategy for controlling aGVHD progression.

Curcumin for the Management of Periodontitis and Early ACPA-Positive Rheumatoid Arthritis: Killing Two Birds with One Stone

We propose curcumin as a preventive measure to avoid/manage periodontitis (PD), and as a natural immunosuppressant for rheumatoid arthritis (RA). PD, mainly caused by Porphyromonas gingivalis forming biofilm and leading to tooth decay, is a major public health issue and a risk factor for the development of RA in humans. P. gingivalis is able to trigger experimental autoimmune arthritis in animal models and in humans can induce citrullinated peptides, which not only are a source of anti-citrullinated antibodies (ACPAs), but also participate in autoreactive responses and disease development. Curcumin appears to have efficient anti-bacterial activity against P. gingivalis infection and biofilm formation. In addition to antibacterial, anti-oxidant, and anti-inflammatory action, curcumin exerts unique immunosuppressant properties via the inhibition of Th17 pro-inflammatory responses and promotion of regulatory T cells, thus suppressing autoimmunity. We introduce curcumin as a natural product for the management of both PD and RA-related autoreactivity, possibly also as a preventive measure in early RA or individuals at high risk to develop RA.

In vivo immunogenicity of bovine bone removed by a novel decellularization protocol based on supercritical carbon dioxide

Trauma or infections associated critical bone defects lead to a huge economic burden in the healthcare system worldwide. Recent advances in tissue engineering have led to potential new strategies for the repair, replacement, and regeneration of bone defects, especially in biomaterials and decellularization protocols from xenogenic tissues. However, the complexity in bone structure and mechanical environment limits the synthesis of artificial bone with biomaterials. Thus, the purpose of our study is to develop a natural bone scaffold with great immunocompatibility. We combined decellularization techniques base on SC-CO₂ to decellularize bovine bone. In order to study the immune response of mice to materials, the histology, spleen index, immune cells contents and in vitro proliferative performance, cytokine and immunoglobulin light chain expression of mice were characterized. Compared with the fresh bone group, the immune responses of decellularized group were significantly reduced. In conclusion, decellularization via this method can achieve a decellularized scaffold with great immunocompatibility. Our findings suggest the potential of using decellularized BB as a scaffold for bone bioengineering.

Herbal Components of a Novel Formula PSORI-CM02 Interdependently Suppress Allograft Rejection and Induce CD8+CD122+PD-1+ Regulatory T Cells

A recipient usually rejects a transplanted organ and thus needs immunosuppressive treatments to prevent rejection. Achieving long-term allograft survival without continuous global immunosuppression is highly desirable in transplantation as long-term immunosuppression causes various side effects. Therefore, it is necessary to search for medicine with potentially less side effects. Traditional Chinese medicine PSORI-CM01 (Yin Xie Ling), a formula with seven natural herbs, has been used to treat patients with psoriasis. Here, we investigated a “sharpened” formula, PSORI-CM02 consisting of only five herbs from PSORI-CM01: Curcumae rhizoma, Radix paeoniae rubra, Rhizoma smilacis glabrae, Mume fructus, and Sarcandrae herba. We examined whether or not PSORI-CM02 would suppress alloimmunity and found that PSORI-CM02 significantly inhibited murine skin allograft rejection and reduced graft-infiltration of CD3+ T cells. Interestingly, omitting any single herbal component rendered the whole formula ineffective in suppression, indicating that these herbal components exert their effects cooperatively as a whole. Moreover, PSORI-CM02 increased CD8+CD122+PD-1+ Treg frequency with CD4+FoxP3+ Tregs remaining unchanged in recipient mice, whereas CsA reduced CD4+FoxP3+ Treg frequency. PSORI-CM02 also hindered CD11c+ DC maturation posttransplantation. Importantly, PSORI-CM02-induced CD8+CD122+PD-1+ Tregs were more potent in suppression of allograft rejection in Rag-/- mice than control Tregs. On the other hand, PSORI-CM02 suppressed T cell proliferation in vitro and reduced their phosphorylation of P70S6K and P50/P65, suggesting that it inhibits both mTOR and NFκB signaling pathways. It also increased IL-10 production while reducing IFNγ level in the supernatant of activated T cells co-cultured with CD8+CD122+PD-1+ Tregs. Furthermore, HPLC fingerprinting ruled out that PSORI-CM02 contained CsA or rapamycin. PSORI-CM02 also did not cause any illness and toxic injury in recipient mice. Thus, we demonstrate that PSORI-CM02 formula suppresses allograft rejection without toxicity.

Obese donor mice splenocytes aggravated the pathogenesis of acute graft-versus-host disease via regulating differentiation of Tregs and CD4+ T cell induced-type I inflammation

Acute graft-versus-host disease (aGVHD) remains one of the most severe complications in organ and bone marrow transplantation, leading to much morbidity and mortality. Obesity has been associated with increased risk of development of various inflammatory diseases. Here, we investigated the in vitro and in vivo effects of obese donor splenocytes on the development of acute graft-versus-host disease (aGVHD). In this study, mixed lymphocyte reactions (MLR) in vitro showed that obese donor mouse CD4+ T cell promoted the production of interleukin-2 (IL-2), interferon (IFN)-γ and tumor necrosis factor (TNF)-α. Meanwhile, the inducible Tregs population decreased greatly in obese donor mouse CD4+ T cells' induction group, compared with normal group. Then in the murine aGVHD model, we found that obese donor splenocytes dramatically increased the severity of aGVHD through down-regulating immune tolerance while enhancing systemic and local immunity. Moreover, we showed that aGVHD induced by obese donors resulted in massive expansion of donor CD3+ T cells, release of Th1-related cytokines, interleukin-17 (IL-17) and chemokines, significant increase of Th17 cells and inhibition of CD4+CD25+Foxp3+ regulatory T cells (Tregs) and impaired suppressive ability of donor Tregs. Expression of sphingosine-1-phosphate receptor 1 (S1PR1), phosphorylated Akt, mammalian target of rapamycin (mTOR) and Raptor increased, while the phosphorylation level of SMAD3 was decreased in the skin, intestine, lung and liver from obese donor splenocytes-treated aGVHD mice. Furthermore, at mRNA and protein levels, we defined several molecules that may account for the enhanced ability of obese donor splenocytes to migrate into target organs, such as IL-2, IL-17, IFN-γ, TNF-α, CXCR3, CXCL9, CXCL10, CXCL11 and CCL3. Therefore, these results imply that obese donor cells may be related to the risk of aGVHD and helping obese donor individuals lose weight represent a compulsory clinical strategy before implementing transplantation to control aGVHD of recipients.

Curcumin attenuates the scurfy-induced immune disorder, a model of IPEX syndrome, with inhibiting Th1/Th2/Th17 responses in mice

BACKGROUND

Immunodysregulation polyendocrinopathy enteropathy X-linked syndrome (IPEX) is a lethal autoimmune disease caused by mutations in the Foxp3 gene scurfin (scurfy). Immunosuppressive therapy for IPEX patients has been generally ineffective and has caused severe side effects, however curcumin has shown immune regulation properties for inflammatory diseases, such as rheumatoid arthritis, psoriasis, and inflammatory bowel diseases without side effects.

OBJECTIVE

The aim of this study was to investigate whether curcumin would attenuate symptoms of IPEX in mouse model and would prolong its survival period.

METHODS

C57BL/6 mice were separated into scurfy or wild-type litter mate groups by genotyping, and each group subsequently was separated into 2 subgroups that were fed a 1% curcumin containing or normal diet from the last day of breast-feeding. After weaning, pups were fed either a 1% curcumin containing or normal diet until all scurfy mice die for survival data. To elucidate immune cell proportions in spleen and lymph nodes, cells were analyzed by flowcytometry. Cellular cytokine production was accessed to investigate the effects of curcumin in T cell differentiation in vitro.

RESULTS

Scurfy mice fed a 1% curcumin diet survived 4.0-fold longer compared to scurfy (92.5 days) mice fed a normal diet (23 days). A curcumin diet decreased all of the Th1/Th2/Th17 cell populations and attenuated diverse symptoms such as splenomegaly in scurfy mice. In vitro experiments showed that curcumin treatment directly decreased the Th1/Th2/Th17 cytokine production of IFN-γ, IL-4, and IL-17A in CD4⁺ T cells.

CONCLUSIONS

Curcumin diet attenuated the scurfy-induced immune disorder, a model of IPEX syndrome, by inhibiting Th1/Th2/Th17 responses in mice. These results have implications for improving clinical therapy for patients with IPEX and other T cell related autoimmune diseases.

White matter damage after traumatic brain injury: A role for damage associated molecular patterns

Traumatic brain injury (TBI) is a leading cause of mortality and long-term morbidity worldwide. Despite decades of pre-clinical investigation, therapeutic strategies focused on acute neuroprotection failed to improve TBI outcomes. This lack of translational success has necessitated a reassessment of the optimal targets for intervention, including a heightened focus on secondary injury mechanisms. Chronic immune activation correlates with progressive neurodegeneration for decades after TBI; however, significant challenges remain in functionally and mechanistically defining immune activation after TBI. In this review, we explore the burgeoning evidence implicating the acute release of damage associated molecular patterns (DAMPs), such as adenosine 5'-triphosphate (ATP), high mobility group box protein 1 (HMGB1), S100 proteins, and hyaluronic acid in the initiation of progressive neurological injury, including white matter loss after TBI. The role that pattern recognition receptors, including toll-like receptor and purinergic receptors, play in progressive neurological injury after TBI is detailed. Finally, we provide support for the notion that resident and infiltrating macrophages are critical cellular targets linking acute DAMP release with adaptive immune responses and chronic injury after TBI. The therapeutic potential of targeting DAMPs and barriers to clinical translational, in the context of TBI patient management, are discussed.

Nutritional control of IL-23/Th17-mediated autoimmune disease through HO-1/STAT3 activation

The nutritional curcumin (CUR) is beneficial in cell-mediated autoimmune diseases. The molecular mechanisms underlying this food-mediated silencing of inflammatory immune responses are poorly understood. By investigating antigen-specific immune responses we found that dietary CUR impairs the differentiation of Th1/Th17 cells in vivo during encephalomyelitis and instead promoted Th2 cells. In contrast, feeding CUR had no inhibitory effect on ovalbumin-induced airway inflammation. Mechanistically, we found that CUR induces an anti-inflammatory phenotype in dendritic cells (DC) with enhanced STAT3 phosphorylation and suppressed expression of Il12b and Il23a. On the molecular level CUR readily induced NRF2-sensitive heme oxygenase 1 (HO-1) mRNA and protein in LPS-activated DC. HO-1 enhanced STAT3 phosphorylation, which enriched to Il12b and Il23a loci and negatively regulated their transcription. These findings demonstrate the underlying mechanism through which a nutritional can interfere with the immune response. CUR silences IL-23/Th17-mediated pathology by enhancing HO-1/STAT3 interaction in DC.

Curcumin ameliorates experimental autoimmune myasthenia gravis by diverse immune cells

Curcumin is a traditional Asian medicine with diverse immunomodulatory properties used therapeutically in the treatment of many autoimmune diseases. However, the effects of curcumin on myasthenia gravis (MG) remain undefined. Here we investigated the effects and potential mechanisms of curcumin in experimental autoimmune myasthenia gravis (EAMG). Our results demonstrated that curcumin ameliorated the clinical scores of EAMG, suppressed the expression of T cell co-stimulatory molecules (CD80 and CD86) and MHC class II, down-regulated the levels of pro-inflammatory cytokines (IL-17, IFN-γ and TNF-α) and up-regulated the levels of the anti-inflammatory cytokine IL-10, shifted the balance from Th1/Th17 toward Th2/Treg, and increased the numbers of NKR-P1(+) cells (natural killer cell receptor protein 1 positive cells, including NK and NKT cells). Moreover, the administration of curcumin promoted the differentiation of B cells into a subset of B10 cells, increased the anti-R97-166 peptide IgG1 levels and decreased the relative affinity indexes of anti-R97-116 peptide IgG. In summary, curcumin effectively ameliorate EAMG, indicating that curcumin may be a potential candidate therapeutic agent for MG.

Oral Curcumin (Meriva) Is Effective as an Adjuvant Treatment and Is Able to Reduce IL-22 Serum Levels in Patients with Psoriasis Vulgaris

Curcumin is a complementary therapy that may be helpful for the treatment of psoriasis due to its anti-inflammatory, antiangiogenic, antioxidant, and antiproliferative effects. In the present study we performed a randomized, double-blind, placebo-controlled clinical trial to assess the effectiveness of a bioavailable oral curcumin in the treatment of psoriasis. Sixty-three patients with mild-to-moderate psoriasis vulgaris (PASI < 10) were randomly divided into two groups treated with topical steroids and Meriva, a commercially available lecithin based delivery system of curcumin, at 2 g per day (arm 1), or with topical steroids alone (arm 2), both for 12 weeks. At the beginning (T0) and at the end of the therapy (T12), clinical assessment and immunoenzymatic analysis of the serum levels of IL-17 and IL-22 were performed. At T12, both groups achieved a significant reduction of PASI values that, however, was higher in patients treated with both topical steroids and oral curcumin than in patients treated only with topical steroids. Moreover, IL-22 serum levels were significantly reduced in patients treated with oral curcumin. In conclusion, curcumin was demonstrated to be effective as an adjuvant therapy for the treatment of psoriasis vulgaris and to significantly reduce serum levels of IL-22.

Sinomenine suppresses collagen-induced arthritis by reciprocal modulation of regulatory T cells and Th17 cells in gut-associated lymphoid tissues

Sinomenine (SIN) has long been used as a therapeutic agent of rheumatoid arthritis (RA) in China. However, the discrepancy between low oral bioavailability and higher minimal effective concentration made its action mode mysterious. The present study aimed to gain insight into the mechanisms by which SIN suppressed collagen-induced arthritis (CIA) in rats in view of Th17 and regulatory T (Treg) cell balance. SIN was orally administered, and the clinical symptoms of CIA rats were monitored; inflammatory cytokines levels in serum were measured by ELISA; pharmacokinetic studies were performed in normal and CIA rats; Th17 and Treg cell frequencies were analyzed by flow cytometry. The data showed that SIN treatment resulted in a dramatic decrease of arthritis scores and paw volume of CIA rats, which was accompanied by down-regulation of IL-17A and up-regulation of IL-10 in rat serum. The frequency of Treg cells was increased and the frequency of Th17 cells was decreased in the gut lymphoid tissues of SIN-treated rats. Immunohistochemistry assay demonstrated that more α4β7-positive cells were detained in joint tissues after SIN treatment. Moreover, the anti-arthritis efficacy of SIN disappeared when it was given by intraperitoneal injection, further confirming the action of SIN was gut-dependent. In conclusion, SIN exerts anti-RA action probably through modulating the frequencies of Treg cells and Th17 cells in intestinal lymph nodes and yielding a trafficking of lymphocytes (especially Treg cells) from gut to joint.

Acute graft-versus-host disease: a bench-to-bedside update

Over the past 5 years, many novel approaches to early diagnosis, prevention, and treatment of acute graft-versus-host disease (aGVHD) have been translated from the bench to the bedside. In this review, we highlight recent discoveries in the context of current aGVHD care. The most significant innovations that have already reached the clinic are prophylaxis strategies based upon a refinement of our understanding of key sensors, effectors, suppressors of the immune alloreactive response, and the resultant tissue damage from the aGVHD inflammatory cascade. In the near future, aGVHD prevention and treatment will likely involve multiple modalities, including small molecules regulating immunologic checkpoints, enhancement of suppressor cytokines and cellular subsets, modulation of the microbiota, graft manipulation, and other donor-based prophylaxis strategies. Despite long-term efforts, major challenges in treatment of established aGVHD still remain. Resolution of inflammation and facilitation of rapid immune reconstitution in those with only a limited response to corticosteroids is a research arena that remains rife with opportunity and urgent clinical need.