Resistance to regulatory T cell-mediated suppression in rheumatoid arthritis can be bypassed by ectopic foxp3 expression in pathogenic synovial T cells

Regulatory T cells in psoriatic arthritis: an IL-17A-producing, Foxp3intCD161 + RORγt + ICOS + phenotype, that associates with the presence of ADAMTSL5 autoantibodies

In psoriatic arthritis (PsA), predisposing class I HLA alleles, the presence of synovial clonally proliferated CD8 + T cells and autoantibodies all point towards the loss of immune tolerance. However, the key mechanisms that lead to immune dysregulation are not fully understood. In other types of inflammatory arthritis, T regulatory cell (Treg) dysfunction and plasticity at sites of inflammation were suggested to negatively affect peripheral tolerance. We here addressed if Treg variances associate with psoriatic disease. We collected clinical data, sera and peripheral blood mononuclear cells from 13 healthy controls, 21 psoriasis and 21 PsA patients. In addition, we obtained synovial fluid mononuclear cells from 6 PsA patients. We studied characteristics of CD4 + CD25 + CD127^loFoxp3 + Tregs by flow cytometry and used ELISA to quantify antibodies against ADAMTSL5, a recently discovered autoantigen in psoriatic disease. In comparison with their circulating counterparts, Tregs from inflamed joints express increased levels of ICOS, CTLA-4 and TIGIT. Furthermore, synovial fluid-derived Tregs have a distinct phenotype, characterized by IL-17A production and upregulation of CD161 and RORγt. We identified a subset of Tregs with intermediate Foxp3 expression as the major cytokine producer. Furthermore, ICOS + Tregs associate with PsA disease activity as measured by PASDAS. Lastly, we observed that presence of the Foxp3^int Tregs associates with an increased abundance of anti-ADAMTSL5 autoantibodies. Tregs derived from the inflammatory environment of inflamed PsA joints exhibit a distinct phenotype, which associates with loss of peripheral immune tolerance in psoriatic disease.

Regulatory T cells in rheumatoid arthritis: functions, development, regulation, and therapeutic potential

Rheumatoid arthritis (RA) is an autoimmune disease that mainly affects the joints but also leads to systemic inflammation. Auto-reactivity and dysregulation of self-tolerance are thought to play a vital role in disease onset. In the pathogenesis of autoimmune diseases, disturbed immunosuppressive properties of regulatory T cells contribute to the dysregulation of immune homeostasis. In RA patients, the functions of Treg cells and their frequency are reduced. Therefore, focusing on the re-establishment of self-tolerance by increasing Treg cell frequencies and preventing a loss of function is a promising strategy for the treatment of RA. This approach could be especially beneficial for those patients who do not respond well to current therapies. In this review, we summarize and discuss the current knowledge about the function, differentiation and regulation of Treg cells in RA patients and in animal models of autoimmune arthritis. In addition, we highlight the therapeutic potential as well as the challenges of Treg cell targeting treatment strategies.

Boosting regulatory T cell function for the treatment of autoimmune diseases – That’s only half the battle!

Regulatory T cells (Treg) represent a subset of specialized T cells that are essential for the regulation of immune responses and maintenance of peripheral tolerance. Once activated, Treg exert powerful immunosuppressive properties, for example by inhibiting T cell-mediated immune responses against self-antigens, thereby protecting our body from autoimmunity. Autoimmune diseases such as multiple sclerosis, rheumatoid arthritis or systemic lupus erythematosus, exhibit an immunological imbalance mainly characterized by a reduced frequency and impaired function of Treg. In addition, there has been increasing evidence that – besides Treg dysfunction – immunoregulatory mechanisms fail to control autoreactive T cells due to a reduced responsiveness of T effector cells (Teff) for the suppressive properties of Treg, a process termed Treg resistance. In order to efficiently treat autoimmune diseases and thus fully induce immunological tolerance, a combined therapy aimed at both enhancing Treg function and restoring Teff responsiveness could most likely be beneficial. This review provides an overview of immunomodulating drugs that are currently used to treat various autoimmune diseases in the clinic and have been shown to increase Treg frequency as well as Teff sensitivity to Treg-mediated suppression. Furthermore, we discuss strategies on how to boost Treg activity and function, and their potential use in the treatment of autoimmunity. Finally, we present a humanized mouse model for the preclinical testing of Treg-activating substances in vivo.

A reasoned approach to the treatment of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease affecting all ages, characterised by elevated transaminase and immunoglobulin G levels, positive autoantibodies, interface hepatitis on histology and good response to immunosuppressive treatment. If untreated, it has a poor prognosis. The aim of this review is to analyse AIH therapeutic interventions with reference to our knowledge of the pathogenesis of AIH. Standard treatment, based on steroids and azathioprine, leads to disease remission in 80-90% of patients. Alternative first-line treatment with budesonide is effective in adults, but less so in the juvenile form of AIH; first-line treatment with ciclosporin does not provide convincing advantages compared to standard treatment. Second-line treatments are needed for patients not responding or intolerant to first-line standard management. Mycophenolate mofetil is the most widely used second-line drug, and has good efficacy particularly for patients intolerant to azathioprine, but is teratogenic. Only few and heterogeneous data on calcineurin inhibitors and m-TOR inhibitors are available. Biologicals, including anti-tumour necrosis factor- α and anti-CD20 monoclonal antibodies, have given ambivalent results and may have severe side-effects. Clinical trials with new therapeutic options aiming at targeting B lymphocytes and proinflammatory cytokines, or expanding regulatory T cells to restore tolerance are ongoing.

Antigen-Specific Regulatory T Cell Therapy in Autoimmune Diseases and Transplantation

Regulatory T (Treg) cells are a heterogenous population of immunosuppressive T cells whose therapeutic potential for the treatment of autoimmune diseases and graft rejection is currently being explored. While clinical trial results thus far support the safety and efficacy of adoptive therapies using polyclonal Treg cells, some studies suggest that antigen-specific Treg cells are more potent in regulating and improving immune tolerance in a disease-specific manner. Hence, several approaches to generate and/or expand antigen-specific Treg cells in vitro or in vivo are currently under investigation. However, antigen-specific Treg cell therapies face additional challenges that require further consideration, including the identification of disease-relevant antigens as well as the in vivo stability and migratory behavior of Treg cells following transfer. In this review, we discuss these approaches and the potential limitations and describe prospective strategies to enhance the efficacy of antigen-specific Treg cell treatments in autoimmunity and transplantation.

Ectopic FOXP3 Expression in Combination with TGF-β1 and IL-2 Stimulation Generates Limited Suppressive Function in Human Primary Activated Thymocytes Ex Vivo

Regulatory T cells (Tregs), which are characterized by the expression of the transcription factor forkhead box P3 (FOXP3), are the main immune cells that induce tolerance and are regulators of immune homeostasis. Natural Treg cells (nTregs), described as CD4⁺CD25⁺FOXP3⁺, are generated in the thymus via activation and cytokine signaling. Transforming growth factor beta type 1 (TGF-β1) is pivotal to the generation of the nTreg lineage, its maintenance in the thymus, and to generating induced Treg cells (iTregs) in the periphery or in vitro arising from conventional T cells (Tconvs). Here, we tested whether TGF-β1 treatment, associated with interleukin-2 (IL-2) and CD3/CD28 stimulation, could generate functional Treg-like cells from human thymocytes in vitro, as it does from Tconvs. Additionally, we genetically manipulated the cells for ectopic FOXP3 expression, along with the TGF-β1 treatment. We demonstrated that TGF-β1 and ectopic FOXP3, combined with IL-2 and through CD3/CD28 activation, transformed human thymocytes into cells that expressed high levels of Treg-associated markers. However, these cells also presented a lack of homogeneous suppressive function and an unstable proinflammatory cytokine profile. Therefore, thymocyte-derived cells, activated with the same stimuli as Tconvs, were not an appropriate alternative for inducing cells with a Treg-like phenotype and function.

Genetic engineering of human and mouse CD4+ and CD8+ Tregs using lentiviral vectors encoding chimeric antigen receptors

The last decade has seen a significant increase of cell therapy protocols using effector T cells (Teffs) in particular, but also, more recently, non-engineered and expanded polyclonal regulatory T cells (Tregs) to control pathological immune responses such as cancer, autoimmune diseases, or transplantation rejection. However, limitations, such as stability, migration, and specificity of the cell products, have been seen. Thus, genetic engineering of these cell subsets is expected to provide the next generation of T cell therapy products. Lentiviral vectors are commonly used to modify Teffs; however, Tregs are more sensitive to mechanical stress and require specific culture conditions. Also, there is a lack of reproducible and efficient protocols to expand and genetically modify Tregs without affecting their growth and function. Due to smaller number of cells and poorer viability upon culture in vitro, mouse Tregs are more difficult to transduce and amplify in vitro than human Tregs. Here we propose a step-by-step protocol to produce both human and mouse genetically modified CD8⁺ and CD4⁺ Tregs in sufficient amounts to assess their therapeutic efficacy in humanized immunocompromised mouse models and murine models of disease and to establish pre-clinical proofs of concept. We report, for the first time, an efficient and reproducible method to isolate Tregs from human blood or mouse spleen, transduce with a lentiviral vector, and culture, in parallel, CD8⁺ and CD4⁺ Tregs while preserving their function. Beyond chimeric antigen receptor (CAR)-Treg cell therapy, this protocol will promote the development of potential new engineered T cell therapies to treat autoimmune diseases and transplantation rejection.

Super-Treg: Toward a New Era of Adoptive Treg Therapy Enabled by Genetic Modifications

Regulatory Tcells (Treg) are essential components of peripheral immune homeostasis. Adoptive Treg cell therapy has shown efficacy in a variety of immune-mediated diseases in preclinical studies and is now moving from phase I/IIa to larger phase II studies aiming to demonstrate efficacy. However, hurdles such as in vivo stability and efficacy remain to be addressed. Nevertheless, preclinical models have shown that Treg function and specificity can be increased by pharmacological substances or gene modifications, and even that conventional T cells can be converted to Treg potentially providing new sources of Treg and facilitating Treg cell therapy. The exponential growth in genetic engineering techniques and their application to T cells coupled to a large body of knowledge on Treg open numerous opportunities to generate Treg with "superpowers". This review summarizes the genetic engineering techniques available and their applications for the next-generation of Super-Treg with increased function, stability, redirected specificity and survival.

Conventional T cell therapies pave the way for novel Treg therapeutics

Approaches to harness the immune system to alleviate disease have become remarkably sophisticated since the crude, yet impressively-effective, attempts using live bacteria in the late 1800s. Recent evidence that engineered T cell therapy can deliver durable results in patients with cancer has spurred frenzied development in the field of T cell therapy. The myriad approaches include an innumerable variety of synthetic transgenes, multiplex gene-editing, and broader application to diseases beyond cancer. In this article, we review the preclinical studies and over a decade of clinical experience with engineered conventional T cells that have paved the way for translating engineered regulatory T cell therapies.

Emerging patterns of regulatory T cell function in tuberculosis

Tuberculosis (TB) is one of the top 10 causes of mortality worldwide from a single infectious agent and has significant implications for global health. A major hurdle in the development of effective TB vaccines and therapies is the absence of defined immune‐correlates of protection. In this context, the role of regulatory T cells (T_reg), which are essential for maintaining immune homeostasis, is even less understood. This review aims to address this knowledge gap by providing an overview of the emerging patterns of T_reg function in TB. Increasing evidence from studies, both in animal models of infection and TB patients, points to the fact the role of T_regs in TB is dependent on disease stage. While T_regs might expand and delay the appearance of protective responses in the early stages of infection, their role in the chronic phase perhaps is to counter‐regulate excessive inflammation. New data highlight that this important homeostatic role of T_regs in the chronic phase of TB may be compromised by the expansion of activated human leucocyte antigen D‐related (HLA‐DR)⁺CD4⁺ suppression‐resistant effector T cells. This review provides a comprehensive and critical analysis of the key features of T_reg cells in TB; highlights the importance of a balanced immune response as being important in TB and discusses the importance of probing not just T_reg frequency but also qualitative aspects of T_reg function as part of a comprehensive search for novel TB treatments.

NF-κB signaling in rheumatoid arthritis with focus on fibroblast-like synoviocytes

The nuclear factor-κB (NF-κB) signaling pathway regulates multiple processes in innate and adaptive immune cells. This pathway is involved in inflammation through the regulation of cytokines, chemokines, and adhesion molecules expression. The NF-κB transcription factor also participates in the survival, proliferation, and differentiation of cells. Therefore, deregulated NF-κB activation contributes to the pathogenesis of inflammatory diseases. Rheumatoid arthritis (RA) is classified as a heterogeneous and complex autoimmune inflammatory disease. Although different immune and non-immune cells contribute to the RA pathogenesis, fibroblast-like synoviocytes (FLSs) play a crucial role in disease progression. These cells are altered during the disease and produce inflammatory mediators, including inflammatory cytokines and matrix metalloproteinases, which result in joint and cartilage erosion. Among different cell signaling pathways, it seems that deregulated NF-κB activation is associated with the inflammatory picture of RA. NF-κB activation can also promote the proliferation of RA-FLSs as well as the inhibition of FLS apoptosis that results in hyperplasia in RA synovium. In this review, the role of NF-κB transcription factor in immune and non-immune cells (especially FLSs) that are involved in RA pathogenesis are discussed.

The Future of Regulatory T Cell Therapy: Promises and Challenges of Implementing CAR Technology

Cell therapy with polyclonal regulatory T cells (Tregs) has been translated into the clinic and is currently being tested in transplant recipients and patients suffering from autoimmune diseases. Moreover, building on animal models, it has been widely reported that antigen-specific Tregs are functionally superior to polyclonal Tregs. Among various options to confer target specificity to Tregs, genetic engineering is a particularly timely one as has been demonstrated in the treatment of hematological malignancies where it is in routine clinical use. Genetic engineering can be exploited to express chimeric antigen receptors (CAR) in Tregs, and this has been successfully demonstrated to be robust in preclinical studies across various animal disease models. However, there are several caveats and a number of strategies should be considered to further improve on targeting, efficacy and to understand the in vivo distribution and fate of CAR-Tregs. Here, we review the differing approaches to confer antigen specificity to Tregs with emphasis on CAR-Tregs. This includes an overview and discussion of the various approaches to improve CAR-Treg specificity and therapeutic efficacy as well as addressing potential safety concerns. We also discuss different imaging approaches to understand the in vivo biodistribution of administered Tregs. Preclinical research as well as suitability of methodologies for clinical translation are discussed.

Novel biomarkers of a peripheral blood interferon signature associated with drug-naïve early arthritis patients distinguish persistent from self-limiting disease course

We profiled gene expression signatures to distinguish rheumatoid arthritis (RA) from non-inflammatory arthralgia (NIA), self-limiting arthritis (SLA), and undifferentiated arthritis (UA) as compared to healthy controls as novel potential biomarkers for therapeutic responsiveness. Global gene expression profiles of PBMCs from 43 drug-naïve patients presenting with joint symptoms were evaluated and differentially expressed genes identified by comparative analysis with 24 healthy volunteers. Patients were assessed at presentation with follow up at 6 and 12 months. Gene ontology and network pathway analysis were performed using DAVID Bioinformatics Resources v6.7. Gene expression profiles were also determined after disease-modifying anti-rheumatic drug (DMARD) treatment in the inflammatory arthritis groups (i.e. RA and UA) and confirmed by qRT-PCR. Receiver operating characteristic (ROC) curves analysis and Area Under the Curve (AUC) estimation were performed to assess the diagnostic value of candidate gene expression signatures. A type I interferon (IFN) gene signature distinguished DMARD-naïve patients who will subsequently develop persistent inflammatory arthritis (i.e. RA and UA) from those with NIA. In patients with RA, the IFN signature is characterised by up-regulation of SIGLEC1 (p = 0.00597) and MS4A4A (p = 0.00000904). We also identified, EPHB2 (p = 0.000542) and PDZK1IP1 (p = 0.0206) with RA-specific gene expression profiles and elevated expression of the ST6GALNAC1 (p = 0.0023) gene in UA. ROC and AUC risk score analysis suggested that MSA4A (AUC: 0.894, 0.644, 0.720), PDZK1IP1 (AUC: 0.785, 0.806, 0.977), and EPHB2 (AUC: 0.794, 0.723, 0.620) at 0, 6, and 12 months follow-up can accurately discriminate patients with RA from healthy controls and may have practical value for RA diagnosis. In patients with early inflammatory arthritis, ST6GALNAC1 is a potential biomarker for UA as compared with healthy controls whereas EPHB2, MS4A4A, and particularly PDZK1IP1 may discriminate RA patients. SIGLEC1 may also be a useful marker of disease activity in UA.

Traitor or warrior-Treg cells sneaking into the lesions of psoriatic arthritis

Regulatory T (Treg) cells have been recognized to maintain immune tolerance, which contributes to prevention of autoimmune diseases. However, recent evidence has demonstrated different characteristics of these cells between those that are in circulation compared to those in various local tissues. In addition, the ability of Treg cells to have plasticity in certain disease settings and in inflammatory lesions has been increasingly recognized. Herein we summarize updated knowledge of Treg biology and discuss the current understanding of tissue-resident Treg cells in psoriatic arthritis (PsA), attempting to provide new insights into precise role of Treg cells in the immune response and as a possible therapeutic intervention in patients with PsA.

Treg cell-based therapies: challenges and perspectives

Cellular therapies using regulatory T (Treg) cells are currently undergoing clinical trials for the treatment of autoimmune diseases, transplant rejection and graft-versus-host disease. In this Review, we discuss the biology of Treg cells and describe new efforts in Treg cell engineering to enhance specificity, stability, functional activity and delivery. Finally, we envision that the success of Treg cell therapy in autoimmunity and transplantation will encourage the clinical use of adoptive Treg cell therapy for non-immune diseases, such as neurological disorders and tissue repair.

The Hypermethylation of Foxp3 Promoter Impairs the Function of Treg Cells in EAP

Treg cells are crucial for maintaining immune homeostasis in CP/CPPS, but the molecular mechanisms underlying the modulation of the function of Treg in CP/CPPS remain unclear. The main purpose of this study is to investigate the relationship between immunosuppressive function of Treg and the methylation level of Foxp3 promoter in experimental autoimmune prostatitis (EAP) mouse model. EAP model was induced by subcutaneous injecting prostate-steroid-binding protein (PSBP) and complete Freund's adjuvant with NOD mice. Histological analysis revealed that EAP model was successfully induced. The expression of IFN-γ was increased, and TGF-β was decreased in the serum of EAP, respectively. The percentage of Tregs in splenic lymphocyte was increased in EAP. The suppressive ability of Tregs on Teffs was impaired in EAP. The methylation level of Foxp3 promoter was increased, and the expression of Foxp3 was decreased in EAP. By injection AZA which was DNA-methylation inhibitor into EAP mice, prostate inflammation was alleviated, expressions of TGF-β and Foxp3 were increased, and the suppressive function of Tregs was improved in vitro and in vivo. Thus, we concluded that aberrant increased methylation of Foxp3 promoter in Treg cells leads to the impaired suppressive function of Treg cells, exacerbating autoimmune inflammatory injury in EAP.

Immunotherapy Deriving from CAR-T Cell Treatment in Autoimmune Diseases

Chimeric antigen receptor T (CAR-T) cells are T cells engineered to express specific synthetic antigen receptors that can recognize antigens expressed by tumor cells, which after the binding of these antigens to the receptors are eliminated, and have been adopted to treat several kinds of malignancies. Autoimmune diseases (AIDs), a class of chronic disease conditions, can be broadly separated into autoantibody-mediated and T cell-mediated diseases. Treatments for AIDs are focused on restoring immune tolerance. However, current treatments have little effect on immune tolerance inverse; even the molecular target biologics like anti-TNFα inhibitors can only mildly restore immune balance. By using the idea of CAR-T cell treatment in tumors, CAR-T cell-derived immunotherapies, chimeric autoantibody receptor T (CAAR-T) cells, and CAR regulatory T (CAR-T) cells bring new hope of treatment choice for AIDs.

The role of α7nAChR in controlling the anti-inflammatory/anti-arthritic action of galantamine

OBJECTIVE

The evolution of the "cholinergic anti-inflammatory pathway" and the fact that the α 7 subunit of the nicotinic acetylcholine receptor (α7nAChR) is present in the spleen, joint and on the surface of lymphocytes, opened up the prospective in this study of targeting the α7nAChR by the anticholinesterase and cholinergic drug, galantamine, to control inflammation in rheumatoid arthritis (RA).

METHODS

Twelve-adjuvant arthritic rats were exposed to the selective α7nAChR blocker methylcaconitine citrate 15 min before galantamine treatment. As control, six adjuvant arthritic rats were treated with galantamine and six others were untreated. After five days TNF-α levels were assessed in spleen and joints, while reduced glutathione was measured in blood and joint tissue. In the second part, magnetically sorted CD4 + T cells from peripheral blood mononuclear cells of RA patients and healthy donors were used to sort CD4 + CD25 - primary T cells (Tresp) and CD4 + CD25 + CD127low Tregs. The suppressive function of Tregs was investigated after incubation with galantamine using flow cytometry. Cell culture supernatants were analyzed for TNF-α and IL-10 levels after three days incubation period of Tregs with Tresp. The effect of galantamine on Tregs was then blocked by α-Bungarotoxin and the same assay has been repeated.

RESULTS & CONCLUSION

Selective α7nAChR blockade interrupted the anti-inflammatory effect of galantamine in the spleen and joints of arthritic rats. In healthy donors, galantamine could strengthen the suppressive activity of Tregs; while in RA patients it did not modulate the function of Tregs significantly. Further studies are necessary to investigate whether modulation of the cholinergic nervous system, especially α7nAChR, could have impact on the disturbed immune system in RA, which may open up a new treatment option of autoimmune diseases.

Dynamic Immune Phenotypes of B and T Helper Cells Mark Distinct Stages of T1D Progression

Multiple studies of B- and T-cell compartments and their response to stimuli demonstrate alterations in established type 1 diabetes (T1D). Yet it is not known whether these alterations reflect immune mechanisms that initiate islet autoimmunity, promote disease progression, or are secondary to disease. To address these questions, we used samples from the TrialNet Pathway to Prevention study to investigate T-cell responses to interleukin (IL)-2 and regulatory T cell-mediated suppression, the composition of the B-cell compartment, and B-cell responses to B-cell receptor and IL-21 receptor engagement. These studies revealed stage-dependent T- and B-cell functional and immune phenotypes; namely, early features that differentiate autoantibody-positive at-risk first-degree relatives (FDRs) from autoantibody-negative FDRs and persisted through clinical diagnosis; late features that arose at or near T1D diagnosis; and dynamic features that were enhanced early and blunted at later disease stages, indicating evolving responses along the continuum of T1D. We further explored how these specific phenotypes are influenced by therapeutic interventions. Our integrated studies provide unique insights into stable and dynamic stage-specific immune states and define novel immune phenotypes of potential clinical relevance.

Reprogrammed CD4+ T Cells That Express FoxP3+ Control Inhibitory Antibody Formation in Hemophilia A Mice

Coagulation Factor VIII (FVIII) replacement therapy in hemophilia A patients is complicated by the development of inhibitory antibodies, which often render the treatment ineffective. Previous studies demonstrated a strong correlation between induction of regulatory T cells (Treg) and tolerance to the therapeutic protein. We, therefore, set out to evaluate whether the adoptive transfer of FVIII-specific CD4⁺ Treg cells prevents inhibitor response to FVIII protein therapy. To this end, we first retrovirally transduced FoxP3⁺ into FVIII-specific CD4⁺ cells, which resulted in cells that stably express FoxP3, are phenotypically similar to peripherally induced Tregs and are antigen specific suppressors, as judged by in vitro assays. Upon transfer of the FVIII-specific CD4⁺ FoxP3⁺ cells into hemophilia A mice, development of inhibitory antibodies in response to administering FVIII protein was completely suppressed. Suppression was extended for 2 months, even after transferred cells were no longer detectable in the secondary lymphoid organs of recipient animals. Upon co-transfer of FoxP3⁺-transduced cells with the B cell depleting anti-CD20 into mice with pre-existing inhibitory antibodies to FVIII, the escalation of inhibitory antibody titers in response to subsequent FVIII protein therapy was dramatically reduced. We conclude that reprogramed FoxP3 expressing cells are capable of inducing the in vivo conversion of endogenous FVIII peripheral Tregs, which results in sustained suppression of FVIII inhibitors caused by replacement therapy in recipient hemophilia A animals.

Gene editing for inflammatory disorders

Technology for precise and efficient genetic editing is constantly evolving and is now capable of human clinical applications. Autoimmune and inflammatory diseases are chronic, disabling, sometimes life-threatening, conditions that feature heritable components. Both primary genetic lesions and the inflammatory pathobiology underlying these diseases represent fertile soil for new therapies based on the capabilities of gene editing. The ability to orchestrate precise targeted modifications to the genome will likely enable cell-based therapies for inflammatory diseases such as monogenic autoinflammatory disease, acquired autoimmune disease and for regenerative medicine in the setting of an inflammatory environment. Here, we discuss recent advances in genome editing and their evolving applications in immunoinflammatory diseases. Strengths and limitations of older genetic modification tools are compared with CRISPR/Cas9, base editing, RNA editing, targeted activators and repressors of transcription and targeted epigenetic modifiers. Commonly employed delivery vehicles to target cells or tissues of interest with genetic modification machinery, including viral, non-viral and cellular vectors, are described. Finally, applications in animal and human models of inflammatory diseases are discussed. Use of chimeric autoantigen receptor T cells, correction of monogenic diseases with genetically edited haematopoietic stem and progenitor cells, engineering of induced pluripotent stem cells and ex vivo expansion and modification of regulatory T cells for a range of chronic inflammatory diseases are reviewed.

Gene Therapy With Regulatory T Cells: A Beneficial Alliance

Gene therapy aims to replace a defective or a deficient protein at therapeutic or curative levels. Improved vector designs have enhanced safety, efficacy, and delivery, with potential for lasting treatment. However, innate and adaptive immune responses to the viral vector and transgene product remain obstacles to the establishment of therapeutic efficacy. It is widely accepted that endogenous regulatory T cells (Tregs) are critical for tolerance induction to the transgene product and in some cases the viral vector. There are two basic strategies to harness the suppressive ability of Tregs: in vivo induction of adaptive Tregs specific to the introduced gene product and concurrent administration of autologous, ex vivo expanded Tregs. The latter may be polyclonal or engineered to direct specificity to the therapeutic antigen. Recent clinical trials have advanced adoptive immunotherapy with Tregs for the treatment of autoimmune disease and in patients receiving cell transplants. Here, we highlight the potential benefit of combining gene therapy with Treg adoptive transfer to achieve a sustained transgene expression. Furthermore, techniques to engineer antigen-specific Treg cell populations, either through reprogramming conventional CD4⁺ T cells or transferring T cell receptors with known specificity into polyclonal Tregs, are promising in preclinical studies. Thus, based upon these observations and the successful use of chimeric (IgG-based) antigen receptors (CARs) in antigen-specific effector T cells, different types of CAR-Tregs could be added to the repertoire of inhibitory modalities to suppress immune responses to therapeutic cargos of gene therapy vectors. The diverse approaches to harness the ability of Tregs to suppress unwanted immune responses to gene therapy and their perspectives are reviewed in this article.

T Regulatory Cell Induced Foxp3 Binds the IL2, IFNγ, and TNFα Promoters in Virus-Specific CD8+ T Cells from Feline Immunodeficiency Virus Infected Cats

Polyfunctional CD8⁺ T cells play a critical role in controlling viremia during AIDS lentiviral infections. However, for most HIV-infected individuals, virus-specific CD8⁺ T cells exhibit loss of polyfunctionality, including loss of IL2, TNFα, and IFNγ. Using the feline immunodeficiency virus (FIV) model for AIDS lentiviral persistence, our laboratory has demonstrated that FIV-activated Treg cells target CD8⁺ T cells, leading to a reduction in IL2 and IFNγ production. Furthermore, we have demonstrated that Treg cells induce expression of the repressive transcription factor, Foxp3, in CD8⁺ T cells. Based upon these findings, we asked if Treg-induced Foxp3 could bind to the IL2, TNFα, and IFNγ promoter regions in virus-specific CD8⁺ T cells. Following coculture with autologous Treg cells, we demonstrated decreased mRNA levels of IL2 and IFNγ at weeks 4 and 8 postinfection and decreased TNFα at week 4 postinfection in virus-specific CD8⁺ T cells. We also clearly demonstrated Treg cell-induced Foxp3 expression in virus-specific CD8⁺ T cells at weeks 1, 4, and 8 postinfection. Finally, we documented Foxp3 binding to the IL2, TNFα, and IFNγ promoters at 8 weeks and 6 months postinfection in virus-specific CD8⁺ T cells following Treg cell coculture. In summary, the results here clearly demonstrate that Foxp3 inhibits IL2, TNFα, and IFNγ transcription by binding to their promoter regions in lentivirus-specific CD8⁺ T cells. We believe this is the first description of this process during the course of AIDS lentiviral infection.

Chimeric Antigen Receptor-Redirected Regulatory T Cells Suppress Experimental Allergic Airway Inflammation, a Model of Asthma

Cellular therapy with chimeric antigen receptor (CAR)-redirected cytotoxic T cells has shown impressive efficacy in the treatment of hematologic malignancies. We explored a regulatory T cell (Treg)-based therapy in the treatment of allergic airway inflammation, a model for asthma, which is characterized by an airway hyper-reactivity (AHR) and a chronic, T helper-2 (Th2) cell-dominated immune response to allergen. To restore the immune balance in the lung, we redirected Tregs by a CAR toward lung epithelia in mice upon experimentally induced allergic asthma, closely mimicking the clinical situation. Adoptively transferred CAR Tregs accumulated in the lung and in tracheobronchial lymph nodes, reduced AHR and diminished eosinophilic airway inflammation, indicated by lower cell numbers in the bronchoalveolar lavage fluid and decreased cell infiltrates in the lung. CAR Treg cells furthermore prevented excessive pulmonary mucus production as well as increase in allergen-specific IgE and Th2 cytokine levels in exposed animals. CAR Tregs were more efficient in controlling asthma than non-modified Tregs, indicating the pivotal role of specific Treg cell activation in the affected organ. Data demonstrate that lung targeting CAR Treg cells ameliorate key features of experimental airway inflammation, paving the way for cell therapy of severe allergic asthma.

Methylation of the FOXP3 upstream enhancer as a clinical indicator of defective regulatory T cells in patients with acute coronary syndrome

Atherosclerosis is an immune-mediated inflammatory process, which acts as the main cause of acute coronary syndrome (ACS). Regulatory CD4+CD25+FOXP3+T cells (Tregs) are thought to play a major role in inhibiting the formation and progression of atherosclerosis. However, the exact role played by Tregs in the pathogenesis of ACS is yet remained unclear. FOXP3 is a key regulator of Treg formation and function. Demethylation at the CpG-rich island of FOXP3 upstream enhancers can alter FOXP3 expression, and may affect Treg function during the development of ACS. This study investigated the immunosuppressive function and methylation status of a FOXP3 upstream enhancer in Tregs in ACS patients. Notably, Tregs from ACS patients exhibited a significantly lower immunosuppressive effect on Teffs. Furthermore, the methylation status of the FOXP3 upstream enhancer was significantly increased in ACS patients. Consistent with these observations, Tregs originated from ACS patients manifested significantly lower levels of FOXP3 mRNA. The immunosuppressive effect of Tregs on Teffs was compromised in ACS patients. Together, our data suggest that examination of the methylation status of the FOXP3 upstream enhancer might be a novel approach to diagnose ACS and to differentiate ACS subtypes.

Predictors of survival in coexistent hypersensitivity pneumonitis with autoimmune features

BACKGROUND

Hypersensitivity pneumonitis (HP), an immune-mediated inflammatory interstitial lung disease (ILD), can result from exposure to several well-recognized antigens. Despite antigen avoidance, progressive pulmonary fibrosis and death can occur, suggesting that additional factors may contribute to disease activity. We hypothesized that the presence of autoimmunity might impact clinical course in patients with HP. In this study, we examined an HP cohort to identify those with HP and autoimmune features (HPAF), and determine its prevalence and outcomes.

METHODS

The University of Chicago ILD registry was screened to identify patients with HP. Patients were characterized as HPAF if they had an autoimmune disease or features of autoimmunity, defined as the presence of specific connective tissue disease (CTD) symptoms and serologies. Demographics, clinical characteristics, and outcomes were compared between groups. Survival analysis was performed using Cox regression to identify predictors of transplant-free survival in this cohort.

RESULTS

One hundred twenty patients with chronic, fibrotic HP were identified. Of these, 18/120 (15%) were characterized as HPAF. Compared to those without evidence of autoimmunity, patients with HPAF had a higher proportion of females (54% vs. 83%, respectively; p = 0.02) but were otherwise similar with regard to clinical characteristics. The presence of autoimmunity was an independent predictor of increased mortality (HR 4.45; 95% CI 1.43-13.88; p = 0.01) after multivariable adjustment.

CONCLUSIONS

Fifteen percent of patients with chronic, fibrotic HP displayed evidence of a concurrent defined autoimmune disease or autoimmune features suggestive of CTD. The presence of autoimmunity in patients with chronic, fibrotic HP may portend a poorer prognosis. Future studies are needed to validate these findings and determine the impact of immunosuppressive treatment.

Sialic acid-modified antigens impose tolerance via inhibition of T-cell proliferation and de novo induction of regulatory T cells

Sialic acids are negatively charged nine-carbon carboxylated monosaccharides that often cap glycans on glycosylated proteins and lipids. Because of their strategic location at the cell surface, sialic acids contribute to interactions that are critical for immune homeostasis via interactions with sialic acid-binding Ig-type lectins (siglecs). In particular, these interactions may be of importance in cases where sialic acids may be overexpressed, such as on certain pathogens and tumors. We now demonstrate that modification of antigens with sialic acids (Sia-antigens) regulates the generation of antigen-specific regulatory T (Treg) cells via dendritic cells (DCs). Additionally, DCs that take up Sia-antigen prevent formation of effector CD4(+) and CD8(+)T cells. Importantly, the regulatory properties endowed on DCs upon Sia-antigen uptake are antigen-specific: only T cells responsive to the sialylated antigen become tolerized. In vivo, injection of Sia-antigen-loaded DCs increased de novo Treg-cell numbers and dampened effector T-cell expansion and IFN-γ production. The dual tolerogenic features that Sia-antigen imposed on DCs are Siglec-E-mediated and maintained under inflammatory conditions. Moreover, loading DCs with Sia-antigens not only inhibited the function of in vitro-established Th1 and Th17 effector T cells but also significantly dampened ex vivo myelin-reactive T cells, present in the circulation of mice with experimental autoimmune encephalomyelitis. These data indicate that sialic acid-modified antigens instruct DCs in an antigen-specific tolerogenic programming, enhancing Treg cells and reducing the generation and propagation of inflammatory T cells. Our data suggest that sialylation of antigens provides an attractive way to induce antigen-specific immune tolerance.

Human Blood and Mucosal Regulatory T Cells Express Activation Markers and Inhibitory Receptors in Inflammatory Bowel Disease

Background

FOXP3⁺ regulatory T cells (Tregs) are critical for preventing intestinal inflammation. However, FOXP3⁺ T cells are paradoxically increased in the intestines of patients with the inflammatory bowel disease (IBD) ulcerative colitis (UC) or Crohn’s disease (CD). We determined whether these FOXP3⁺ cells in IBD patients share or lack the phenotype of such cells from patients without IBD.

Methods

We quantified and characterized FOXP3⁺ Treg populations, as well as FOXP3^- CD4⁺ T cells, in the lamina propria lymphocytes (LPL) of intestine surgically resected from patients with and without IBD, and in the blood of controls or Crohn’s patients with or without disease activity.

Results

In all samples, a similar fraction of FOXP3⁺ cells expressed the “natural” Treg (nTreg) marker Helios, suggesting that, in IBD, these cells are not entirely “induced” Tregs (iTregs) derived from activated effector T cells. Helios⁺ and Helios^- FOXP3⁺ T cells demonstrated similar expression of maturation markers, activation markers, and inhibitory molecules between IBD patients and controls, while FOXP3^- cells paradoxically expressed more of the inhibitory receptors CD39, CTLA4, and PD-1 in inflamed mucosa. Greater expression of activation markers was also seen in both Helios⁺ and Helios^- Tregs, relative to FOXP3^- cells, in both IBD patients and controls, indicating that Tregs are effectively activated by antigen in IBD.

Conclusions

Extensive immunophenotyping revealed that Helios⁺ and Helios^- mucosal Tregs exist at a similar frequency, and have a similar expression of inhibitory molecules and activation markers in patients with IBD as in healthy controls.

Exclusive Transduction of Human CD4+ T Cells upon Systemic Delivery of CD4-Targeted Lentiviral Vectors

Playing a central role in both innate and adaptive immunity, CD4(+) T cells are a key target for genetic modifications in basic research and immunotherapy. In this article, we describe novel lentiviral vectors (CD4-LV) that have been rendered selective for human or simian CD4(+) cells by surface engineering. When applied to PBMCs, CD4-LV transduced CD4(+) but not CD4(-) cells. Notably, also unstimulated T cells were stably genetically modified. Upon systemic or intrasplenic administration into mice reconstituted with human PBMCs or hematopoietic stem cells, reporter gene expression was predominantly detected in lymphoid organs. Evaluation of GFP expression in organ-derived cells and blood by flow cytometry demonstrated exclusive gene transfer into CD4(+) human lymphocytes. In bone marrow and spleen, memory T cells were preferentially hit. Toward therapeutic applications, we also show that CD4-LV can be used for HIV gene therapy, as well as for tumor therapy, by delivering chimeric Ag receptors. The potential for in vivo delivery of the FOXP3 gene was also demonstrated, making CD4-LV a powerful tool for inducible regulatory T cell generation. In summary, our work demonstrates the exclusive gene transfer into a T cell subset upon systemic vector administration opening an avenue toward novel strategies in immunotherapy.

Methotrexate Restores Regulatory T Cell Function Through Demethylation of the FoxP3 Upstream Enhancer in Patients With Rheumatoid Arthritis

OBJECTIVE

We have previously shown, in a cohort of untreated rheumatoid arthritis (RA) patients, that the suppressive function of Treg cells is defective. However, other studies in cohorts of patients with established RA have shown that Treg cell function is normal. We hypothesized that treatment may restore Treg cell function and lead to reduced disease activity. The aim of this study was to investigate whether treatment with methotrexate (MTX) can result in epigenetic changes that lead to restoration of the Treg cell suppressive function in RA.

METHODS

Peripheral blood samples from RA patients were assessed using (3) H-thymidine incorporation to measure Treg cell suppression of T cell proliferation, and by enzyme-linked immunosorbent assay to determine Treg cell suppression of interferon-γ production. CTLA-4 and FoxP3 expression was measured by flow cytometry and quantitative polymerase chain reaction (qPCR) in Treg cells from healthy individuals and RA patients. CD4+ T cells isolated from healthy individuals were cultured with interleukin-2 (IL-2), IL-6, and tumor necrosis factor α in the presence or absence of MTX, and FoxP3 expression was determined using qPCR and flow cytometry. Methylation of the FOXP3 upstream enhancer was analyzed by bisulfite sequencing PCR.

RESULTS

Defective Treg cell function was observed only in RA patients who had not been treated with MTX, whereas Treg cells from MTX-exposed RA patients had restored suppressive function. This restored suppression was associated with increased expression of FoxP3 and CTLA-4 in Treg cells. Bisulfite sequencing PCR of Treg cells cultured in MTX revealed a significant reduction in methylation of the FOXP3 upstream enhancer.

CONCLUSION

This study identifies a novel mechanism of action of MTX, in which treatment of RA patients with MTX restores defective Treg cell function through demethylation of the FOXP3 locus, leading to a subsequent increase in FoxP3 and CTLA-4 expression.

Polyfunctional, Pathogenic CD161+ Th17 Lineage Cells Are Resistant to Regulatory T Cell-Mediated Suppression in the Context of Autoimmunity

In autoimmune diseases such as rheumatoid arthritis (RA), regulatory T cells (Tregs) fail to constrain autoimmune inflammation; however, the reasons for this are unclear. We investigated T cell regulation in the RA joint. Tregs from RA synovial fluid suppressed autologous responder T cells; however, when compared with Tregs from healthy control peripheral blood, they were significantly less suppressive. Despite their reduced suppressive activity, Tregs in the RA joint were highly proliferative and expressed FOXP3, CD39, and CTLA-4, which are markers of functional Tregs. This suggested that the reduced suppression is due to resistance of RA synovial fluid responder T cells to Treg inhibition. CD161(+) Th17 lineage cells were significantly enriched in the RA joint; we therefore investigated their relative susceptibility to Treg-mediated suppression. Peripheral blood CD161(+) Th cells from healthy controls were significantly more resistant to Treg-mediated suppression, when compared with CD161(-) Th cells, and this was mediated through a STAT3-dependant mechanism. Furthermore, depletion of CD161(+) Th cells from the responder T cell population in RA synovial fluid restored Treg-mediated suppression. In addition, CD161(+) Th cells exhibited pathogenic features, including polyfunctional proinflammatory cytokine production, an ability to activate synovial fibroblasts, and to survive and persist in the inflamed and hypoxic joint. Because CD161(+) Th cells are known to be enriched at sites of autoinflammation, our finding that they are highly proinflammatory and resistant to Treg-mediated suppression suggests an important pathogenic role in RA and other autoimmune diseases.

Cell-penetrable mouse forkhead box protein 3 alleviates experimental arthritis in mice by up-regulating regulatory T cells

Regulatory T cells (T(regs)) have potential applications in clinical disease therapy, such as autoimmune diseases and transplant rejection. However, their numbers are limited. Forkhead box protein 3 (FoxP3) is a key transcription factor that controls T(reg) development and function. Here, we generated a cell-permeable fusion protein, protein transduction domain (PTD)-conjugated mouse FoxP3 protein (PTD-mFoxP3), and evaluated whether PTD-mFoxp3 can alleviate rheumatoid arthritis (RA) in the collagen-induced arthritis (CIA) mouse model. As expected, PTD-mFoxP3 was transduced into cells effectively, and inhibited T cell activation and attenuated the cell proliferation. It decreased interleukin (IL) 2 and interferon (IFN)-γ expression, and increased IL-10 expression in activated CD4(+)CD25(-) T cells. PTD-mFoxP3-transduced CD4(+)CD25(-) T cells attenuated proliferation of activated CD4(+)CD25(-) T cells. In addition, PTD-mFoxP3 blocked the Th17 differentiation programme in vitro and down-regulated IL-17 production from T cells by modulating induction and levels of retinoid-related orphan receptor gamma t (RORγt). Intra-articular delivery of PTD-mFoxP3 delayed disease incidence remarkably and alleviated autoimmune symptoms of CIA mice. Moreover, protective effects of PTD-mFoxP3 were associated with regulating the balance of T helper type 17 (Th17) and T(regs). These results suggest that PTD-mFoxP3 may be a candidate for RA therapy.

Genetic polymorphisms of Foxp3 in patients with rheumatoid arthritis

OBJECTIVE

The aim of the study was to identify 2 polymorphic variants in the promoter region of the Foxp3 gene and their possible association with susceptibility to and severity of rheumatoid arthritis (RA). The association between genetic factors and pathogenesis suggests that T cells take part in the induction of RA. The CD4+CD25highFoxp3+ subset of regulatory T cells plays an essential role in preventing autoimmunity and maintaining immune homeostasis.

METHODS

Patients with RA (n = 274) and healthy individuals (n = 295) were examined for -3279 C/A and -924 A/G Foxp3 gene polymorphisms by the polymerase chain reaction-restriction fragment-length polymorphism method. Serum Foxp3 levels in patients with RA and controls were measured with ELISA.

RESULTS

Foxp3 -3279 A and -924 G alleles were associated with significantly elevated risk of RA in the population tested (p = 0.003 and p = 0.004, respectively) compared to the wild-type alleles. Overall, -3279 C/A and -924 A/G Foxp3 gene polymorphisms were in indistinct linkage disequilibrium with D' = 0.481 and r(2) = 0.225. From 4 possible haplotypes, frequencies of 2 (AG and CA) showed significant differences between both examined groups (respectively, p < 0.001 and p = 0.007). After appropriate adjustment of Bonferroni correction for multiple testing, the genotype-phenotype analysis showed no significant correlation of the Foxp3 -3279 C/A and -924 A/G polymorphisms with the disease activity, joint damage, laboratory variables, and extraarticular manifestation in patients with RA. Serum Foxp3 level was significantly higher in patients than in controls (p < 0.0001).

CONCLUSION

Current findings indicated that the Foxp3 genetic polymorphism and the Foxp3 protein level may be associated with susceptibility to RA in the Polish population.

A novel upstream enhancer of FOXP3, sensitive to methylation-induced silencing, exhibits dysregulated methylation in rheumatoid arthritis Treg cells

Treg-cell function is compromised in rheumatoid arthritis (RA). As the master regulator of Treg cells, FOXP3 controls development and suppressive function. Stable Treg-cell FOXP3 expression is epigenetically regulated; constitutive expression requires a demethylated Treg-specific demethylated region. Here, we hypothesised that methylation of the FOXP3 locus is altered in Treg cells of established RA patients. Methylation analysis of key regulatory regions in the FOXP3 locus was performed on Treg cells from RA patients and healthy controls. The FOXP3 Treg-specific demethylated region and proximal promoter displayed comparable methylation profiles in RA and healthy-donor Treg cells. We identified a novel differentially methylated region (DMR) upstream of the FOXP3 promoter, with enhancer activity sensitive to methylation-induced silencing. In RA Treg cells we observed significantly reduced DMR methylation and lower DNA methyltransferase (DNMT1/3A) expression compared with healthy Treg cells. Furthermore, DMR methylation negatively correlated with FOXP3 mRNA expression, and Treg cells isolated from rheumatoid factor negative RA patients were found to express significantly higher levels of FOXP3 than Treg cells from RhF-positive patients, with an associated decrease in DMR methylation. In conclusion, the novel DMR is involved in the regulation of Treg-cell FOXP3 expression, but this regulation is lost post-transcriptionally in RA Treg cells.

Anti-inflammatory effect of resveratrol on adjuvant arthritis rats with abnormal immunological function via the reduction of cyclooxygenase-2 and prostaglandin E2

Rheumatoid arthritis (RA) is a chronic inflammatory disease with unknown etiology. The present study investigated the anti-inflammatory effect of resveratrol on rats with adjuvant arthritis (AA) with abnormal immunological function via the reduction of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2). AA model rats were established by injection of complete Freund's adjuvant and alterations in the rats secondary paw swelling and the polyarthritic scores were observed. Pathological examination of joint tissues was observed by hematoxylin and eosin staining. The proliferation of spleen cells was examined using a 3-(4,5-dimethylthiazol-2‑yl)-2,5-diphenyltetrazolium bromide assay in vitro. The protein expression of COX-2 in the synovial tissues was detected by western blotting. The level of PGE2 in the serum was assayed using an ELISA kit. The results demonstrated that resveratrol (10 or 50 mg/kg) was able to significantly reduce paw swelling and decrease the arthritis scores. Compared with the AA model rats, a significant reduction in the proliferation of concanavalin A-stimulated spleen cells was observed, articular cartilage degeneration with synovial hyperplasia and inflammatory cell infiltration was suppressed and the production of COX-2 and PGE2 in AA rats was reduced by treatment with resveratrol. These results suggest that resveratrol has significant anti-inflammatory effects on AA rats, which may be associated with the reduction of COX-2 and PGE2 inflammatory mediators.

Suppression of murine colitis and its associated cancer by carcinoembryonic antigen-specific regulatory T cells

The adoptive transfer of regulatory T cells (Tregs) offers a promising strategy to combat pathologies that are characterized by aberrant immune activation, including graft rejection and autoinflammatory diseases. Expression of a chimeric antigen receptor (CAR) gene in Tregs redirects them to the site of autoimmune activity, thereby increasing their suppressive efficiency while avoiding systemic immunosuppression. Since carcinoembryonic antigen (CEA) has been shown to be overexpressed in both human colitis and colorectal cancer, we treated CEA-transgenic mice that were induced to develop colitis with CEA-specific CAR Tregs. Two disease models were employed: T-cell-transfer colitis as well as the azoxymethane-dextran sodium sulfate model for colitis-associated colorectal cancer. Systemically administered CEA-specific (but not control) CAR Tregs accumulated in the colons of diseased mice. In both model systems, CEA-specific CAR Tregs suppressed the severity of colitis compared to control Tregs. Moreover, in the azoxymethane-dextran sodium sulfate model, CEA-specific CAR Tregs significantly decreased the subsequent colorectal tumor burden. Our data demonstrate that CEA-specific CAR Tregs exhibit a promising potential in ameliorating ulcerative colitis and in hindering colorectal cancer development. Collectively, this study provides a proof of concept for the therapeutic potential of CAR Tregs in colitis patients as well as in other autoimmune inflammatory disorders.

Foxp3 gene expression in oral lichen planus: a clinicopathological study

CD4+CD25+ Forkhead‑box protein 3 (Foxp3+) regulatory T cells are important in oral lichen planus (OLP). The present study aimed to investigate Foxp3 expression in CD4+CD25+ T cells of peripheral blood mononuclear cells and oral lesions in patients diagnosed with OLP, who were grouped as OLP subtype, duration and relapse. Using quantitative polymerase chain reaction (qPCR), western blotting and immunohistochemistry, Foxp3 expression levels in explants of oral lesions and CD4+CD25+ T cells from 32 patients with OLP were measured and compared, with 10 healthy subjects as the control group. Foxp3 mRNA expression levels in the explants of oral lesions and circulating CD4+CD25+ T cells in patients with OLP were significantly higher than those in the control group (P<0.05). In patients with clinically erosive lesions, Foxp3 mRNA expression was significantly lower in circulating CD4+CD25+ T cells and tissue explants compared to patients with reticular lesions (P<0.01 and P<0.05, respectively), and lowest in patients with a history of OLP of >1 year or with a history of relapse (P<0.05 and P<0.01, respectively). Foxp3 protein levels in reticular OLP were significantly higher than those in erosive OLP and the control group. The incidence of Foxp3 protein expression in OLP tissues was 36.24±18.92 and 10.44±6.51% in normal oral mucosa (P=0.019). Atrophic/erosive OLP lesions showed a higher proportion of Foxp3‑expressing cells than that of reticular OLP lesions (P<0.05). This study indicated that Foxp3 expression in patients with OLP is associated with the severity and duration of the disorder, suggesting altered immune suppression in the development, clinical course and responsiveness to treatment.

Rheumatoid arthritis with deficiency pattern in traditional chinese medicine shows correlation with cold and hot patterns in gene expression profiles

In our precious study, the correlation between cold and hot patterns in traditional Chinese medicine (TCM) and gene expression profiles in rheumatoid arthritis (RA) has been explored. Based on TCM theory, deficiency pattern is another key pattern diagnosis among RA patients, which leads to a specific treatment principle in clinical management. Therefore, a further analysis was performed aiming at exploring the characteristic gene expression profile of deficiency pattern and its correlation with cold and hot patterns in RA patients by bioinformatics analysis approach based on gene expression profiles data detected with microarray technology. The TCM deficiency pattern-related genes network comprises 7 significantly, highly connected regions which are mainly involved in protein transcription processes, protein ubiquitination, toll-like receptor activated NF- κ B regulated gene transcription and apoptosis, RNA clipping, NF- κ B signal, nucleotide metabolism-related apoptosis, and immune response processes. Toll-like receptor activated NF- κ B regulated gene transcription and apoptosis pathways are potential specific pathways related to TCM deficiency patterns in RA patients; TCM deficiency pattern is probably related to immune response. Network analysis can be used as a powerful tool for detecting the characteristic mechanism related to specific TCM pattern and the correlations between different patterns.

The effect of autoimmune arthritis treatment strategies on regulatory T-cell dynamics

PURPOSE OF REVIEW

Since their discovery over 15 years ago, intensive research has focused on the presence, phenotype and function of FOXP3(+) regulatory T cells (Treg) in autoimmune diseases such as rheumatoid arthritis (RA). The questions of whether Treg deficiencies underlie autoimmune pathology and whether or how Treg-related therapeutic approaches might be successful are still a subject of a vivid debate. In this review we give an overview of how current therapies influence Treg numbers and function in RA and juvenile idiopathic arthritis (JIA) and discuss these findings in the light of new Treg-based intervention strategies for autoimmune arthritis.

RECENT FINDINGS

The attempt to relate rheumatic diseases like rheumatoid arthritis and juvenile idiopathic arthritis to Treg has led to somewhat heterogeneous observations. So far, no clear defects in Treg numbers or function have been identified in autoimmune arthritis. The current standard therapies, that is methotrexate and biologicals, are generally effective, but the exact mechanism of action and their effect on Treg is not fully known. Nevertheless, the majority of in-vitro and ex-vivo data point towards a positive influence of these treatments on Treg number and function. These observations are not all consistent, however, and it is not known whether the observed effects on Treg are primary or secondary effects. To safely conduct targeted regulatory T-cell therapy in rheumatic diseases more knowledge about regulatory T-cell function in an inflammatory environment is needed that coincides with the initiative to elucidate the exact mechanism of current therapies.

Anti-TNF-α therapy improves Treg and suppresses Teff in patients with rheumatoid arthritis

Anti-TNF-α therapies have been applied in RA treatment, but the regulatory effect of the drug on immune system is not clear. In this study, we included 33 active RA patients and divided them into two groups. One group received anti-TNF-α mAb+methotrexate for 24 weeks, the other group got placebo+methotrexate for the first 12 weeks and anti-TNF-α mAb+methotrexate for another 12 weeks. Circulatory regulatory T cell (Treg) and effector T cell (Teff) frequency was analyzed pre-therapy and week 12 and week 24 for both group patients by flowcytometry. Our results indicated significantly elevated Treg and decreased Teff at week 24 compared with pre-therapy and week 12 for both group patients, and a little higher Treg and lower Teff frequency in anti-TNF-α therapy group than in placebo therapy patients. Our results demonstrated anti-TNF-α therapy has regulatory effect on immune system of RA patients by promoting Treg proportion increase and suppressing Teff.