Type 1 diabetes immunotherapy using polyclonal regulatory T cells

Autoantigen and IL-2 activated CD4+CD25+T regulatory cells are induced to express CD8 and are autoantigen specific in inhibiting experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) induced by immunization with myelin basic protein (MBP) is a self-limiting disease model of multiple sclerosis. CD4+CD25+Foxp3+T cells play a role in limiting autoimmune disease but treatment with antigen naïve CD4+CD25+ cells does not reduce EAE. This study examined if in vitro activation by MBP and rIL-2 induced CD4+CD25+Foxp3+ cells that could inhibit EAE. Culture of CD4+CD8-CD25+cells from naïve rats with MBP and rIL-2 induced activated Treg that reduced the severity of clinical EAE and infiltration of CD8+T cells and macrophage into brain stem. CD4+CD25+T cells activated by an irrelevant autoantigen and rIL-2 did not suppress EAE. Resting CD4+CD25+T cells activated by autoantigen and rIL-2 have mRNA for Infgr, Il12rb2, Il5 but not Tbet, Gata3, Ilr5ra or Ifng. These changes in mRNA expression are the markers of Ts1 cells. A proportion of CD4+CD8-CD25+ cells activated by MBP/rIL-2 were induced to express CD8α, CD8β and CD62L. Depletion of CD4+CD8α+CD25+ cells removed the capacity of MBP and rIL-2 activated CD4+CD25+T cells to suppress EAE. This study demonstrated that in vitro activation of CD4+CD8-CD25+ cells by MBP/rIL-2 induced relevant antigen-specific Treg within days, which expressed CD8α, CD8β and CD62L with a Ts1 phenotype and that had greater potency than freshly isolated antigen naive CD4+CD25+Treg in suppressing clinical severity of EAE and immune inflammation in CNS. These findings may guide development of antigen-specific Treg for therapy.

Armored human CAR Treg cells with PD1 promoter-driven IL-10 have enhanced suppressive function

Regulatory T cell (Treg cell) therapy has been transformed through the use of chimeric antigen receptors (CARs). We previously found that human Treg cells minimally produce IL-10 and have a limited capacity to control innate immunity compared to type 1 regulatory T cells (Tr1 cells). To create "hybrid" CAR Treg cells with Tr1 cell-like properties, we examined whether the PDCD1 locus could be exploited to endow Treg cells with CAR-regulated IL-10 expression. CRISPR-mediated PD1 deletion increased CAR Treg cell activation, and knock-in of IL10 under control of the PD1 promoter resulted in CAR-induced IL-10 secretion. IL10 knock-in improved CAR Treg cell function, as determined by increased suppression of dendritic cells and alloantigen- and islet autoantigen-specific T cells. In vivo, IL10 knock-in CAR Treg cells were stable, safe, and suppressed dendritic cells and xenogeneic graft-versus-host disease. CRISPR-mediated engineering to simultaneously remove an inhibitory signal and enhance a suppressive mechanism is a previously unexplored approach to improve CAR Treg cell potency.

Osteogenesis imperfecta: exploring an autoimmune and immunotherapy perspective

Osteogenesis imperfecta (OI), also called brittle bone disease, is a genetic osteodysplasia characterized by a defect in type 1 collagen. Often diagnosed in infancy or early childhood, young patients are affected by frequent fractures. Osteogenesis imperfecta was first named almost 200 yr ago, yet there are still no FDA-approved treatments for OI, and existing treatments target only the skeletal defects of the disease. In this review, we briefly examine current treatments and ongoing clinical trials. Then, by analyzing OI with an osteoimmunological perspective, we have compiled evidence that OI has an autoimmune component. This autoimmune component of OI remains unconsidered, even though an immunology-based therapy has shown promise in treating OI. Acknowledging an autoimmune component of OI is critical to understanding its mechanisms and allowing for the development of more efficacious treatments and novel immunotherapies. Considering the existing literature and the growing impact of immunotherapeutic therapies in cancer and other autoimmune diseases, we believe it may be time to rethink the immune aspects of this genetic disorder and develop novel immunomodulating strategies to improve the quality of life for OI patients.

Initial or continuous coculture with umbilical cord-derived mesenchymal stromal cells facilitates in vitro expansion of human regulatory T-cell subpopulations

Clinical trials have demonstrated the safety and potential efficacy of ex vivo expanded regulatory T cells (Tregs) for immune-mediated diseases. Nonetheless, achieving consistent and timely Treg yield and purity remains challenging. We aimed to evaluate the potential to enhance culture expansion of primary human total Treg (CD4+/CD25+/CD127lo) and Treg subpopulations through coculture with human umbilical cord-derived mesenchymal stromal cells (hUC-MSCs). In 14- to 21-day anti-CD3/anti-CD28-, interleukin-2-, and rapamycin-containing cultures, fluorescence-activated cell sorting (FACS)-purified total Treg underwent 4-fold greater expansion following hUC-MSC coculture. Potency to suppress T effector cell (Teff) proliferation was equivalent for hUC-MSC-cocultured and control Tregs and correlated with the expression of HLA-DR, CD39, and inducible costimulator (ICOS). The impact of hUC-MSC coculture on ex vivo expansion of 3 FACS-purified Treg subpopulations [CD45RA+ (Subtype I), CD45RA-HLA-DR+ (Subtype II), and CD45RA-HLA-DR- (Subtype III)] was then investigated. Both initial and continuous hUC-MSC coculture yielded significantly higher fold expansion of each Treg subpopulation compared to control. However, the magnitude of enhancement was substantially greater for non-naive (Subtypes II and III) than for naive (Subtype I) Treg. Coculture with hUC-MSC increased HLA-DR expression of all 3 expanded Treg subpopulations while maintaining comparable Teff suppressive potency. For non-naive Treg (Subtypes II and III), both initial and continuous hUC-MSC coculture also increased the final %Foxp3+ and %Helios+. Thus, coculture with clinical-grade hUC-MSC substantially enhances the ex vivo yield, preserves the suppressive potency, and modulates HLA-DR expression of FACS-purified Treg subpopulations with greatest effect on non-naive (CD45RA-) Treg. The findings have potential to facilitate identification, functional characterization, and manufacturing of Treg subpopulations with distinct therapeutic benefits.

Expression of an interleukin-2 partial agonist enhances regulatory T cell persistence and efficacy in mouse autoimmune models

Regulatory T (Treg)-based cell therapy holds promise for autoimmune and inflammatory diseases, yet challenges remain regarding the functional stability and persistence of transferred Tregs. Here we engineer Tregs to express a partial agonist form of IL-2 (IL-2pa) to enhance persistence while avoiding toxicity from excessive signaling. Mouse Tregs expressing wild-type IL-2 (Tregs-IL2wt) have only a transient growth advantage, limited by toxicity from likely excessive signaling. By contrast, mouse Tregs-IL2pa exhibit sustained expansion, long-term survival in immunocompetent mice for over a year, and bystander expansion of endogenous Tregs. Tregs-IL2pa maintain a stable activated phenotype, Treg-specific demethylation, and a diverse TCR repertoire. In vivo, prophylactic transfer of Tregs-IL2pa ameliorates multi-organ autoimmunity in a Treg depletion-induced mouse autoimmune model. Lastly, compared with control Treg, human Tregs-IL2pa show enhanced survival in the IL-2-depleted environment of immune-deficient mice and improved control of xenogeneic graft-versus-host disease. Our results thus show that IL-2pa self-sufficiency enhances the stability, durability and efficacy of Treg therapies in preclinical settings.

Drug-loaded microneedle patches containing regulatory T cell-derived exosomes for psoriasis treatment

Psoriasis is a chronic inflammatory skin disease characterized by epidermal hyperplasia, skin inflammation, and immune dysregulation. These factors contribute to the persistent progression of the disease. While addressing excessive keratinocyte proliferation or inhibiting inflammation may provide temporary therapeutic relief, unresolved immune dysregulation often exacerbates the condition. Therefore, comprehensive treatments that alleviate skin symptoms and regulate immune tolerance are urgently required. An ideal treatment would target multiple factors, including keratinocyte proliferation, inflammation, and immune tolerance, while minimizing systemic side effects. In this study, we developed a dissolvable hyaluronic acid microneedle patch containing regulatory T cell (Treg) exosomes loaded with dimethyl fumarate (DMF) (rExo@DMF MNs). DMF acts as an inhibitor of keratinocyte proliferation and an anti-inflammatory agent through NF-κB suppression and Nrf2 activation, inhibiting the production of pro-inflammatory cytokines and the activation of inflammatory cells. Delivering DMF via Treg exosomes enhances its retention at the lesion site. This system inhibits keratinocyte proliferation and migration, reduces pro-inflammatory cytokine release, and alleviates epidermal hyperplasia and inflammation in an imiquimod-induced psoriasis mouse model. Additionally, Treg exosomes modulate immune responses to promote tolerance. rExo@DMF MNs demonstrate immunomodulatory effects by inhibiting T helper 17 (Th17) cells and inducing regulatory immune cells such as Tregs and tolerogenic dendritic cells (tDCs) differentiation. rExo@DMF MNs alleviate skin symptoms and regulate immune cells in the skin, spleen, and lymph nodes, demonstrating both local and systemic immunoregulation with promising therapeutic potential for psoriasis. STATEMENT OF SIGNIFICANCE: Novel therapies are urgently needed to alleviate skin symptoms and regulate immunity, as current psoriasis treatments focus on symptom relief while neglecting the underlying immune dysfunction, resulting in limited efficacy. Moreover, systemic immunosuppression often leads to severe side effects. This study introduces a hybrid microneedle system (rExo@DMF MNs) that alleviates psoriasis symptoms and modulates immune responses locally and systemically. In addition, rExo@DMF MNs penetrate hyperkeratotic skin, ensuring targeted rExo@DMF release while minimizing systemic exposure and side effects. All components of the system, including hyaluronic acid (a key component of the skin matrix), regulatory T cell-derived exosomes, and DMF (a clinically validated drug), exhibit biocompatibility. This comprehensive approach addresses multiple pathogenic factors, promising an effective and safe psoriasis treatment.

Type 1 Diabetes: A Guide to Autoimmune Mechanisms for Clinicians

Type 1 diabetes (T1D) results from the destruction of pancreatic beta cells by autoreactive T lymphocytes, leading to insulin deficiency and lifelong insulin dependence. It develops in genetically predisposed individuals, triggered by environmental or immunological factors. Although the exact causes of T1D remain unknown, the autoimmune pathogenesis of the disease is clearly indicated by the genetic risk conferred by allelic human leukocyte antigens (HLA), the almost obligatory presence of islet cell autoantibodies (AAbs) and immune cell infiltration of pancreatic islets from patients. At the same time, epidemiological data point to a role of environmental factors, notably enteroviral infections, in the disease, although precise causative links between specific pathogens and T1D have been difficult to establish. Studies of human pancreas organs from patients made available through repositories and the advent of high-dimensional high-throughput technologies for genomic and proteomic studies have significantly elucidated our understanding of the disease in recent years and provided mechanistic insights that can be exploited for innovative targeted therapeutic approaches. This short overview will summarise current salient knowledge on immune cell and beta cell dysfunction in T1D pathogenesis. PLAIN LANGUAGE SUMMARY: Type 1 diabetes (T1D) is a chronic disease where the body's own immune system attacks and destroys the insulin-producing beta cells in the pancreas. This leads to a lack of insulin, a hormone essential for regulating blood sugar, which means people with T1D need insulin for life. The disease can develop at any age but is most diagnosed in children and young adults. Despite advances in treatment, T1D still significantly reduces life expectancy, especially in countries with fewer healthcare resources. T1D develops in people with a genetic predisposition, often triggered by environmental factors such as viral infections or changes in the gut microbiome. The disease progresses silently through three stages: Stage 1: Autoantibodies to beta cell components appear, signalling the immune system is reacting against the pancreas, but there are no symptoms; Stage 2: Beta cell function starts to decline, but fasting blood sugar is still normal; Stage 3: Enough beta cells are destroyed that fasting blood sugar rises, and symptoms of diabetes appear. The risk of progressing from stage 1 to full-blown diabetes is about 35-50% within five years, and even higher from stage 2. Over 60 genes are linked to T1D risk, most of which affect how the immune system works. The strongest genetic risk comes from specific versions of histocompatibility genes, which help the immune system distinguish between the body's own cells and invaders. Some types of these genes make it easier for the immune system to mistakenly attack beta cells. However, 90% of people diagnosed with T1D have no family member with T1D, showing that genetics is only part of the story. Environmental factors also play a big role. For example, certain viral infections, especially with viruses infecting the intestine, are associated with a higher risk of developing T1D. The gut microbiome - the community of bacteria living in our intestines - also influences risk, with healthier, more diverse microbiomes appearing to offer some protection. In T1D, immune cells - especially so-called T lymphocytes - mistake beta cells in the pancreas for threats and destroy them. This process is called autoimmunity. The attack is often reflected by the presence of autoantibodies against proteins found in beta cells. Over time, as more beta cells are lost, the body can no longer produce enough insulin, leading to the symptoms of diabetes. Interestingly, not all people with T1D have the same pattern of disease. For example, children diagnosed before age 7 often have more aggressive disease, more autoantibodies, and stronger genetic risk factors than those diagnosed later. Much of our understanding of T1D has come from studying animal models, but new technologies now allow researchers to study human pancreas tissue and blood immune cells in greater detail. Scientists are also exploring how the gut microbiome, diet, and environmental exposures contribute to T1D risk and progression. Treatment currently focuses on replacing insulin, but researchers are working on therapies that target the immune system or aim to protect or replace beta cells. Strategies include immunotherapy, gene therapy, and even modifying the gut microbiome. The goal is to prevent or reverse the disease, not just manage its symptoms. In summary, T1D is a complex autoimmune disease influenced by both genes and the environment. It progresses silently before symptoms appear, and while insulin therapy is life-saving, new research is paving the way for treatments that could one day halt or even prevent the disease.

The Role of Tregs in the Tumor Microenvironment

The tumor microenvironment (TME) is a unique ecosystem that surrounds tumor tissues. The TME is composed of extracellular matrix, immune cells, blood vessels, stromal cells, and fibroblasts. These environments enhance cancer development, progression, and metastasis. Recent success in immune checkpoint blockade also supports the importance of the TME and immune cells residing in the tumor niche. Although the TME can be identified in almost all cancer types, the role of the TME may not be similar among different cancer types. Regulatory T cells (Tregs) play a pivotal role in immune homeostasis and are frequently found in the TME. Owing to their suppressive function, Tregs are often considered unfavorable factors that allow the immune escape of cancer cells. However, the presence of Tregs is not always linked to an unfavorable phenotype, which can be explained by the heterogeneity and plasticity of Tregs. In this review, the current understanding of the role of Tregs in TME is addressed for each cancer cell type. Moreover, recently a therapeutic approach targeting Tregs infiltrating in the TME has been developed including drug antibody conjugate, immunotoxin, and FOXP3 inhibiting peptide. Thus, understanding the role of Tregs in the TME may lead to the development of novel therapies that directly target the TME.

IsoalloLCA-intervened regulatory T cell exosomes alleviate inflammatory bowel disease by inhibiting NF-κB-associated inflammation in intestinal epithelial cells

Regulatory T cells (Tregs) are the principal immune cells that exert anti-inflammatory effects within the organism. Their exosomes exhibit therapeutic efficacy across a broad spectrum of diseases owing to their high stability, low immunogenicity, and substantial penetration capacity. Recent research have indicated that isoallolithocholic acid (isoalloLCA), a metabolite associated with bile acid metabolism, may enhance Treg activity by upregulating forkhead box protein3 (Foxp3) expression. Hence, metabolite-based strategies for reinforcing Tregs may offer novel intervention options for treating related diseases. In this study, tumor necrosis factor (TNF)-α and dextran sulfate sodium (DSS) were employed to establish cellular and animal models of inflammatory bowel disease (IBD), further evaluating the therapeutic efficacy of isoalloLCA-intervened regulatory T cell exosomes (isoalloLCA-Exo) within this model. Our findings demonstrated that isoalloLCA-Exo effectively inhibit colitis progression in a murine model, as indicated by reduced inflammation, decreased apoptosis of intestinal epithelial cells, and improved intestinal barrier function. Furthermore, in vitro analyses elucidated the molecular mechanisms underlying the anti-inflammatory effects of isoalloLCA-Exo, revealing that the intervention effectively reversed TNF-α-induced inflammation and apoptosis in intestinal epithelial cells by modulating the NF-κB pathway. In conclusion, isoalloLCA-Exo can decelerate inflammatory bowel disease progression and suppress inflammatory response in intestinal epithelial cells by inhibiting NF-κB pathway. Notably, isoalloLCA-Exo exhibit superior efficacy to the traditional drug mesalazine and conventional treg exosome(NC-Exo). These findings have significant implications for optimizing Treg-derived exosome-based therapies for inflammation-related diseases.

Tissue Engineering and Regenerative Medicine: Perspectives and Challenges

From the pioneering days of cell therapy to the achievement of bioprinting organs, tissue engineering, and regenerative medicine have seen tremendous technological advancements, offering solutions for restoring damaged tissues and organs. However, only a few products and technologies have received United States Food and Drug Administration approval. This review highlights significant progress in cell therapy, extracellular vesicle-based therapy, and tissue engineering. Hematopoietic stem cell transplantation is a powerful tool for treating many diseases, especially hematological malignancies. Mesenchymal stem cells have been extensively studied. The discovery of induced pluripotent stem cells has revolutionized disease modeling and regenerative applications, paving the way for personalized medicine. Gene therapy represents an innovative approach to the treatment of genetic disorders. Additionally, extracellular vesicle-based therapies have emerged as rising stars, offering promising solutions in diagnostics, cell-free therapeutics, drug delivery, and targeted therapy. Advances in tissue engineering enable complex tissue constructs, further transforming the field. Despite these advancements, many technical, ethical, and regulatory challenges remain. This review addresses the current bottlenecks, emphasizing novel technologies and interdisciplinary research to overcome these hurdles. Standardizing practices and conducting clinical trials will balance innovation and regulation, improving patient outcomes and quality of life.

Adoptive transfer of regulatory T cells inhibits the progression of endometriosis-like lesions in regulatory T-cell-depleted mice

STUDY QUESTION

Does the restoration of regulatory T cells (Tregs) suppress the progression of endometriosis?

SUMMARY ANSWER

Adoptive transfer of Tregs suppresses the progression of endometriosis and reduces the levels of helper T (Th)-cell-related and proinflammatory cytokines in mice.

WHAT IS KNOWN ALREADY

Endometriosis is a chronic inflammatory gynecological disease, which involves multiple immune components. Activated Treg counts decrease in the endometrioma and endometrium of patients with endometriosis, and depletion of Tregs exacerbates endometriosis in mice.

STUDY DESIGN, SIZE, DURATION

We evaluated the effects of adoptive transfer of Tregs on the progression of endometriosis in mice. We used Foxp3tm3Ayr/J (Foxp3DTR) mice with temporarily ablated Tregs by injecting diphtheria toxin to develop an endometriosis model, which was generated by ovariectomy, estradiol administration and transplantation of uterine fragments from donor mice. Foxp3DTR mice were randomly divided into Treg adoptive transfer (n = 12) and control (n = 11) groups. Tregs were isolated from lymph nodes and spleens of wild-type (WT) mice and were adoptively transferred into mice that were temporarily Treg-depleted. Control mice were injected with vehicle. Treg adoptive transfer was performed on the day of uterine implantation, and a second adoptive transfer was performed after 14 days. Mice were euthanized 28 days after uterine implantation, and blood, peritoneal fluid, spleen, and endometriosis-like lesion samples were collected.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Foxp3DTR mice were intravenously injected with Tregs isolated from WT mice. The number, total weight, and total volume of the endometriosis-like lesions were evaluated on Day 28 following implantation of uterine fragments. The proportion of Tregs in endometriosis-like lesions, ascites, and peripheral blood was analyzed by flow cytometry. Inflammation in lesions and serum was examined using real-time PCR and ELISA.

MAIN RESULTS AND THE ROLE OF CHANCE

Injection of Tregs increased their total count and decreased the number (P < 0.0001), weight (P = 0.0021), and volume (P = 0.0010) of endometriosis-like lesions in Foxp3DTR Treg-depleted mice. Furthermore, injection of Tregs decreased the mRNA expression of Th 1-, 2-, and 17-related cytokines, including interferon gamma (P = 0.0101), interleukin (IL)-4 (P = 0.0051), and IL-17 (P = 0.0177), as well as the levels of the proinflammatory cytokine IL-6 (P = 0.0002), in endometriosis-like lesions of Foxp3DTR Treg-depleted mice.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Treg-related immune mechanisms in mice may not precisely reflect those in humans.

WIDER IMPLICATIONS OF THE FINDINGS

Restoration of Tregs may be a useful therapeutic strategy for inhibiting the progression of endometriosis in cases where the decrease in the Treg population is an exacerbating factor.

STUDY FUNDING/COMPETING INTEREST(S)

This study was partially supported by the Grants-in-Aid for Scientific Research (grant numbers 18K16808 and 20K22983) from the Ministry of Education, Culture, Sports, Science, and Technology, Japan. The sponsor had no role in the study design, collection, analysis and interpretation of data, writing of the report, and decision to submit the article for publication. The authors have no conflicts of interest to disclose.

Advances in Regulatory Cell Therapy for Type 1 Diabetes: Emerging Strategies and Future Directions

Type 1 diabetes (T1D) is an autoimmune disorder characterized by the destruction of insulin-producing β-cells in the pancreas. Despite advances in insulin therapy and β-cell replacement, a definitive cure addressing the underlying cause of the disease, that is the loss of immune tolerance to β-cells remains elusive. Emerging strategies to reshape the immune response to pancreatic autoantigens include the adoptive transfer of ex vivo cultured regulatory cells, either mesenchymal stem cells (MSCs), regulatory T cells (Tregs), or dendritic cells (DCs), collectively known as regulatory cell therapy. This review aims to provide an overview of the regulatory cell-based approaches for T1D currently under development. Although several clinical trials have demonstrated the safety of in vivo administration of regulatory cells to T1D patients, only mild signs of efficacy have been reported. The most promising results were observed in patients with shorter disease duration and higher residual β-cell mass, suggesting that early interventions may result in clinical benefit. Significant challenges remain, including the long-term efficacy and stability of the infused products. In the future, approaches combining regulatory cell-based therapies with immunomodulatory agents or strategies to restore the damaged insulin-producing cells may hold the key to achieving a functional cure for T1D.

Transfer of bone marrow niche-residential regulatory T cells ameliorates experimental colitis

BACKGROUND

Adoptive transfer of regulatory T cells (Tregs) has been proposed as a next-generation treatment approach for the treatment of various inflammatory or autoimmune disorders(Amini et al., 2022; Bluestone et al., 2023, 2015; Dall'Era et al., 2019; Chandran et al., 2017; Laukova and Glatman Zaretsky, 2023; Voskens et al., 2023; Canavan et al., 20161-8), inclusive of inflammatory bowel diseases (IBD). Identification of the appropriate Treg populations as donor sources for effective cell therapy is of great importance. We have recently identified specialized Tregs that localize within the hematopoietic stem cell (HSC) microenvironments(Fujisaki et al., 2011; Hirata et al., 2018, 2019, 2015; Kakiuchi et al., 2021a, 2021b; Furuhashi et al., 20259-16) of bone marrow (BM), termed HSC niches. These BM niche Tregs exhibit robust anti-inflammatory and pro-regenerative effects and render HSCs immune privileged. The transfer of BM niche Tregs exhibits high therapeutic effects against BM transplantation and injury(Hirata et al., 2018; Kakiuchi et al., 2021b10, 14). Yet, the treatment effects of transferred BM niche Tregs in non-BM disease settings remain unknown.

OBJECTIVES

We investigated the therapeutic effects of transfer of BM niche Tregs for IBD using mouse models of experimental colitis. To identify the key effector molecule of niche Tregs, we further examined the roles of cell-surface ectoenzyme CD39 expressed at high levels by BM niche Tregs.

STUDY DESIGN

Mouse colitis was induced by administering dextran sulfate sodium salt. Subsequently, the mice received intravenous injections of BM niche Tregs, BM non-niche Tregs, lymph node Tregs, or vehicle alone. We compared these treatment effects on clinical scores, histopathological features and profiles of immune cells. We also tested how targeted deletion of CD39 in the adoptively transferred Tregs impacted experimental outcomes.

RESULTS

The transfer of as few as 1.5 × 104 BM niche Tregs per mouse ameliorated clinical and histopathological features of the mouse colitis far better than the transfer of other Tregs. The transfer of BM niche Tregs inhibited the generation of Th17 cells and promoted the regeneration and recovery of the colon tissue. Targeted deletion of CD39 in Tregs abrogated therapeutic effects of transferred BM niche Tregs.

CONCLUSION

We show robust therapeutic effects of the transfer of BM niche Tregs in the experimental model of colitis. Donor niche Tregs mediate anti-inflammatory and pro-regenerative effects via Treg CD39. Our work suggests the transfer of BM niche Tregs is a promising approach to treat colitic disorders and boost tissue regeneration.

Therapeutic application of regulatory T cell in osteoarthritis

Regulatory T cells (Tregs) are the specific T cell population that suppress inflammatory immunity. Independent of their inhibitory activities, Tregs exhibit unique capacity to repair tissue damage. Rapid progresses are made in the processing and engineering of Tregs for clinical applications. Tregs have been used in the treatment of autoimmune diseases, transplantation rejection and graft-versus-host disease. Osteoarthritis is one of the major diseases that affect at least 600 million people worldwide. Osteoarthritis is characterized by physical erosion of cartilage, accompanied with chronic and low-grade inflammation. Tregs possess abilities to increase osteoclast differentiation and bone resorption, repair bone physical damage, and increase bone mass. Tregs are therefore candidate therapeutics for osteoarthritis for both inflammation resolution and tissue repairing. In this review, we will summarize the recent development in using Tregs in immunotherapy, and the potential of using Tregs in osteoarthritis.

Immunomodulatory agents and cell therapy for patients with type 1 diabetes

Type 1 diabetes (TID) is a chronic disease caused by autoimmune destruction of pancreatic β-cells, that progresses in three stages: 1) stage 1: β-cell autoimmunity + normoglycemia; 2) stage 2: β-cell autoimmunity + mild dysglycemia; 3) stage 3: symptomatic disease + hyperglycemia. Interventions to prevent or cure T1D in the various stages of the disease have been pursued and may target the prevention of the destruction of β cells, regression of insulitis, preservation or recovery of β cells residual mass. Some therapies show promising results that might change the natural history and the approach to patients with T1D in the next few years. Teplizumab, a humanized monoclonal antibody that binds to CD3, was recently approved in the USA to delay Stage 3 T1D in individuals ≥ 8 years of age. Other non-cellular immunomodulatory therapies, both antigen-specific and non-specific, have shown interesting results either in patients with stage 2 or recent onset stage 3 T1D. Cell therapies such as non-myeloablative transplantation of autologous hematopoietic stem cells, mesenchymal stem cells, and tolerogenic dendritic cells have been also studied in these individuals, aiming immunomodulation. Stem cell-derived islet replacement therapy is promising for patients with long- standing T1D, especially with asymptomatic hypoglycemia not resolved by technology. This review aimed to provide updated information on the main immunomodulatory agents and cell therapy options for type 1 diabetes.

Potential regulation of artesunate on bone metabolism through suppressing inflammatory infiltration in type 2 diabetes mellitus

OBJECTIVE

Osteoimmunology is an emerging field that explores the interplay between bone and the immune system. The immune system plays a critical role in the pathogenesis of diabetes and significantly affects bone homeostasis. Artesunate, a first-line treatment for malaria, is known for its low toxicity and multifunctional properties. Increasing evidence suggests that artesunate possesses anti-inflammatory, immunoregulatory, and osteogenic effects. This review aims to explore the relationship between immune regulation and bone metabolism in type 2 diabetes (T2DM) and to investigate the potential therapeutic application of artesunate.

METHODS

This review systematically examines literature from PubMed/Medline, Elsevier, Web of Science, Embase, the International Diabetes Federation, and other relevant databases.

RESULTS

This review synthesizes evidence from multiple sources to delineate the relationship between T lymphocytes and T2DM, the regulation of T lymphocyte subsets in bone metabolism, and the effects of artesunate on both T lymphocytes and bone metabolism. Recent studies suggest a bidirectional regulatory relationship between T2DM and T lymphocytes (CD4+ T and CD8+ T) during the onset and progression of the disease, with inflammatory and anti-inflammatory cytokines serving as key mediators. T lymphocyte subsets and their cytokines play a pivotal role in regulating osteogenesis and osteoclastogenesis in pathological conditions. Furthermore, artesunate has shown promise in modulating inflammatory infiltration and bone metabolism.

CONCLUSION

The accumulated evidence indicates that artesunate exerts regulatory effects on bone metabolism in T2DM by influencing T lymphocyte differentiation.

Engineered antigen-specific T regulatory cells suppress autoreactivity to the anti-glomerular basement membrane disease antigen

Anti-glomerular basement membrane (anti-GBM) disease is accompanied by insufficient antigen-specific regulatory T cells (Tregs) and clonally expanded antigen-specific conventional T cells. In particular, this applied to the immunodominant T cell autoepitope of type IV collagen, α3(IV)NC1135-145, presented by human leukocyte antigen-DRB1∗1501. Here, we investigated whether Tregs engineered to express GBM-T cell receptors (TCR) specific for α3(IV)NC1135-145 better suppress autoimmunity. The GBM-TCR Treg cell product exhibited a phenotypically stable Treg phenotype, produced α3(IV)NC1135-145-specific functional responses, and were superior suppressors of autoreactive conventional T cells and bystander conventional T cells compared to polyclonal Tregs or irrelevant TCR-transduced Tregs. We also found that GBM-TCR Tregs modulate other immune cells like dendritic cells and B cells to a more tolerogenic phenotype. Importantly, our findings support the development of GBM-TCR Tregs as a promising cell-based therapy for anti-GBM disease.

Diverse potential of chimeric antigen receptor-engineered cell therapy: Beyond cancer

BACKGROUND

Chimeric antigen receptor (CAR)-engineered cell therapies have made significant progress in haematological cancer treatment. This success has motivated researchers to investigate its potential applications in non-cancerous diseases, with substantial strides already made in this field.

MAIN BODY

This review summarises the latest research on CAR-engineered cell therapies, with a particular focus on CAR-T cell therapy for non-cancerous diseases, including but not limited to infectious diseases, autoimmune diseases, cardiac diseases and immune-mediated disorders in transplantation. Additionally, the review discusses the current obstacles that need to be addressed for broader clinical applications.

CONCLUSION

With ongoing research and continuous improvements, CAR-engineered cell therapy holds promise as a potent tool for treating various diseases in the future.

KEY POINTS

CAR-engineered cell therapy has expanded beyond cancer to treat autoimmune diseases, infections, cardiac diseases, and transplant-related rejection. The CAR platform is diverse, with various cell types such as CAR-T, CAR-NK, and CAR-M potentially suited for different disease contexts. The safety, efficacy, and practicality of CAR cell therapy in non-cancer diseases remain challenging, requiring further technological optimization and clinical translation.

Regulatory T cell-based therapies for type 1 diabetes: a narrative review

Type 1 diabetes (T1D) is an autoimmune disease caused by the destruction of pancreatic insulin-secreting beta cells, resulting in hyperglycemia and a lifelong need for exogenous insulin therapy. Regulatory T cells (Tregs) are essential for maintaining immune tolerance and preventing autoimmune reactions. It has been shown that dysfunctional Tregs participate in the pathophysiology of T1D. Therapeutic approaches designed to enhance Treg stability, survival, and function have progressively emerged as a promising treatment strategy for T1D. This narrative review explores the potential of Treg cell-based therapy as a therapeutic tool to alter the natural history of T1D. It discusses different pharmacological strategies to enhance Treg stability and function, as well as the latest advances in Treg cell-based therapies, including adoptive Treg cell therapy and genetic engineering of Tregs. It also outlines current challenges and future research directions for integrating Treg cell-based therapy into clinical practice, aiming to provide a comprehensive overview of its potential benefits and limitations as an innovative therapeutic intervention for T1D.

Dysregulation and therapeutic prospects of regulatory T cells in type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease that selectively destroys β-cells in the pancreas that produce insulin. Several studies have implicated and elaborated the significant role of regulatory T cells (Tregs) in the pathogenesis of T1D. Tregs are a specialized subset of T cells and are critical regulators of peripheral self-tolerance. However, if the number, function, or stability of these cells is altered, it can lead to autoimmunity. This review summarizes the current knowledge and understanding about Treg function in both health and T1D, Tregs dysregulation, and various factors, including microRNAs, that affect their dysregulation in T1D. The review also focuses on the advantages and challenges of Treg-based therapies for T1D.

A Multidisciplinary Approach of Type 1 Diabetes: The Intersection of Technology, Immunotherapy, and Personalized Medicine

Background: Type 1 diabetes (T1D) is a chronic autoimmune disorder characterized by the destruction of pancreatic β-cells, leading to absolute insulin deficiency. Despite advancements in insulin therapy and glucose monitoring, achieving optimal glycemic control remains a challenge. Emerging technologies and novel therapeutic strategies are transforming the landscape of T1D management, offering new opportunities for improved outcomes. Methods: This review synthesizes recent advancements in T1D treatment, focusing on innovations in continuous glucose monitoring (CGM), automated insulin delivery systems, smart insulin formulations, telemedicine, and artificial intelligence (AI). Additionally, we explore biomedical approaches such as stem cell therapy, gene editing, immunotherapy, gut microbiota modulation, nanomedicine-based interventions, and trace element-based therapies. Results: Advances in digital health, including CGM integration with hybrid closed-loop insulin pumps and AI-driven predictive analytics, have significantly improved real-time glucose management. AI and telemedicine have enhanced personalized diabetes care and patient engagement. Furthermore, regenerative medicine strategies, including β-cell replacement, CRISPR-based gene editing, and immunomodulatory therapies, hold potential for disease modification. Probiotics and microbiome-targeted therapies have demonstrated promising effects in maintaining metabolic homeostasis, while nanomedicine-based trace elements provide additional strategies to regulate insulin sensitivity and oxidative stress. Conclusions: The future of T1D management is shifting toward precision medicine and integrated technological solutions. While these advancements present promising therapeutic avenues, challenges such as long-term efficacy, safety, accessibility, and clinical validation must be addressed. A multidisciplinary approach, combining biomedical research, artificial intelligence, and nanotechnology, will be essential to translate these innovations into clinical practice, ultimately improving the quality of life for individuals with T1D.

Synthetic receptor-based cell therapies for autoimmune diseases: an update

Increasing frequency of autoimmune diseases is one of the major problems in modern societies. Despite the introduction of new therapeutic agents for autoimmunity over the past several decades, more progress is needed. Synthetic receptor-based cell therapies are being adopted as an option for treating autoimmune diseases from the field of oncology. Currently evaluated strategies can be summarized into two approaches. The first one is the elimination of autoreactive cells by targeting them, for example, with CAR-T or CAAR-T cells. The second is based on rebalancing the proinflammatory milieu with engineered immunosuppressive cells, for example, CAR-Treg. Both approaches can be supplemented with the use of synthetic systems such as Split-CAR, SynNotch, MESA, GEMS, and SNIPR, or prospective off-the-shelf approaches, for example, in situ use of the in vitro transcribed mRNA, ultimately allowing for enhanced efficacy and safety. The primary goal of our review is to provide some perspective on both strategies in basic, translational, and clinical studies with all their advantages and disadvantages to allow for informed future design of adoptive cell therapies for autoimmune diseases.

Advances in the Pathogenesis and Treatment Strategies for Type 1 Diabetes Mellitus

Type 1 diabetes (T1D) is a complex autoimmune disorder distinguished by the infiltration of immune cells into pancreatic islets, primarily resulting in damage to pancreatic β-cells. Despite extensive research, the precise pathogenesis of T1D remains elusive, with its etiology linked to a complex interplay of genetic, immune, and environmental factors. While genetic predispositions, such as HLA and other susceptibility genes, are necessary, they do not fully account for disease development. Environmental influences such as viral infections and dietary factors may contribute to the disease by affecting the immune system and epigenetic modifications. Additionally, endogenous retroviruses (ERVs) might play a role in T1D pathogenesis. Current therapeutic approaches, including insulin replacement therapy, immune omodulatory therapy, autoantigen immunotherapy, organ transplantation, and genetic modification, offer potential to alter disease progression but are still constrained by limitations. This review presents updated knowledge on T1D, with a focus on risk factors, predisposing hypotheses, and recent advancements in therapeutic strategies.

A Granzyme B-Cleavable T Cell-Targeted Bispecific Cell Vesicle Connector for Reversing New-Onset Type 1 Diabetes

Type 1 diabetes (T1D) is an autoimmune disorder in which pancreatic β-cells are destroyed by CD8+ T cells. Anti-CD3 antibody effectively treats early-stage T1D when β-cell autoantibodies are detected but before symptoms appear. However, it impairs the immune system temporarily, exposing individuals to infection. A therapeutic that can reverse new-onset T1D without harming the immune system remains urgently needed. Herein, we have constructed cellular vesicles presenting granzyme B-responsive fusion proteins (designated aCD8-GrzBcs-IL2) composed of a single-chain variable fragment of anti-CD8 antibodies and a mutein interleukin-2 (IL2). aCD8-GrzBcs-IL2 is designed to simultaneously inhibit CD8+ T cells and promote Treg cells, especially when CD8+ T cells are attacking β-cells. In vitro, these cellular vesicles can inhibit the cell-killing effect of CD8+ T cells and enhance the expansion of Treg cells. Notably, intravenous administration of aCD8-GrzBcs-IL2-expressed cellular vesicles reversed newly onset diabetes in 77.8% of nonobese diabetic (NOD) mice without reducing blood CD3+ T cells and CD8+ T cells, indicating a favorable safety profile.

T-regulatory cells for the treatment of autoimmune diseases

Autoimmune diseases result from imbalances in the immune system and disturbances in the mechanisms of immune tolerance. T-regulatory cells (Treg) are key factors in the formation of immune tolerance. Tregs modulate immune responses and repair processes, controlling the innate and adaptive immune system. The use of Tregs in the treatment of autoimmune diseases began with the manipulation of endogenous Tregs using immunomodulatory drugs. Then, a method of adoptive transfer of Tregs grown in vitro was developed. Adoptive transfer of Tregs includes polyclonal Tregs with non-specific effects and antigen-specific Tregs in the form of CAR-Treg and TCR-Treg. This review discusses non-specific and antigen-specific approaches to the use of Tregs, their advantages, disadvantages, gaps in development, and future prospects.

Antigen-specific immunotherapies for autoimmune disease

Antigen-specific therapies have a long history in the treatment of allergy but have not been successful in autoimmunity. However, in the past 20 years, advances in the definition of the self-antigens that promote autoimmunity and the growing understanding of the mechanisms that maintain tolerance in health but fail in autoimmunity have led to antigen-specific approaches being considered for the treatment of autoimmune diseases. The core goal of each antigen-specific treatment approach is to remove the immune response that promotes autoimmunity whilst sparing protective responses. Approaches to antigen-specific therapy range from targeted deletion of autoreactive lymphocytes to tolerization of autoreactive T cells and active inhibition of autoimmune responses. Technologies such as vaccines, nanoparticles, cell-based therapies and gene editing are being harnessed to achieve these goals. Remaining challenges include the selection of the best antigen to target, modality and timing of administration of these therapies and the disease in which the therapies are used; overcoming these challenges will be vital to move antigen-specific therapies forward. Once established, antigen-specific therapy has the potential to be applied broadly in the area of autoimmunity.

The Efficiency of Brain-Derived Neurotrophic Factor Secretion by mRNA-Electroporated Regulatory T Cells Is Highly Impacted by Their Activation Status

Genetic engineering of regulatory T cells (Tregs) presents a promising avenue for advancing immunotherapeutic strategies, particularly in autoimmune diseases and transplantation. This study explores the modification of Tregs via mRNA electroporation, investigating the influence of T-cell activation status on transfection efficiency, phenotype, and functionality. For this CD45RA+ Tregs were isolated, expanded, and modified to overexpress brain-derived neurotrophic factor (BDNF). Kinetics of BDNF expression and secretion were explored. Treg activation state was assessed by checking the expression of activation markers CD69, CD71, and CD137. Our findings show that only activated Tregs secrete BDNF post-genetic engineering, even though both activated and resting Tregs express BDNF intracellularly. Notably, the mTOR pathway and CD137 are implicated in the regulation of protein secretion in activated Tregs, indicating a complex interplay of signalling pathways. This study contributes to understanding the mechanisms governing protein expression and secretion in engineered Tregs, offering insights for optimizing cell-based therapies and advancing immune regulation strategies.

Harnessing the biology of regulatory T cells to treat disease

Regulatory T (Treg) cells are a suppressive subset of CD4+ T cells that maintain immune homeostasis and restrain inflammation. Three decades after their discovery, the promise of strategies to harness Treg cells for therapy has never been stronger. Multiple clinical trials seeking to enhance endogenous Treg cells or deliver them as a cell-based therapy have been performed and hint at signs of success, as well as to important limitations and unanswered questions. Strategies to deplete Treg cells in cancer are also in active clinical testing. Furthermore, multi-dimensional methods to interrogate the biology of Treg cells are leading to a refined understanding of Treg cell biology and new approaches to harness tissue-specific functions for therapy. A new generation of Treg cell clinical trials is now being fuelled by advances in nanomedicine and synthetic biology, seeking more precise ways to tailor Treg cell function. This Review will discuss recent advances in our understanding of human Treg cell biology, with a focus on mechanisms of action and strategies to assess outcomes of Treg cell-targeted therapies. It highlights results from recent clinical trials aiming to enhance or inhibit Treg cell activity in a variety of diseases, including allergy, transplantation, autoimmunity and cancer, and discusses ongoing strategies to refine these approaches.

Improving regulatory T cell-based therapy: insights into post-translational modification regulation

Regulatory T (Treg) cells are pivotal for maintaining immune homeostasis and play essential roles in various diseases, such as autoimmune diseases, graft-versus-host disease (GVHD), tumors, and infectious diseases. Treg cells exert suppressive function via distinct mechanisms, including inhibitory cytokines, granzyme or perforin-mediated cytolysis, metabolic disruption, and suppression of dendritic cells. Forkhead Box P3 (FOXP3), the characteristic transcription factor, is essential for Treg cell function and plasticity. Cumulative evidence has demonstrated that FOXP3 activity and Treg cell function are modulated by a variety of post-translational modifications (PTMs), including ubiquitination, acetylation, phosphorylation, methylation, glycosylation, poly(ADP-ribosyl)ation, and uncharacterized modifications. This review describes Treg cell suppressive mechanisms and summarizes the current evidence on PTM regulation of FOXP3 and Treg cell function. Understanding the regulatory role of PTMs in Treg cell plasticity and function will be helpful in designing therapeutic strategies for autoimmune diseases, GVHD, tumors, and infectious diseases.

Induction of Antigen-Specific Tolerance in a Multiple Sclerosis Model without Broad Immunosuppression

Multiple sclerosis (MS) is a severe autoimmune disorder that wreaks havoc on the central nervous system, leading to a spectrum of motor and cognitive impairments. There is no cure, and current treatment strategies rely on broad immunosuppression, leaving patients vulnerable to infections. To address this problem, our approach aims to induce antigen-specific tolerance, a much-needed shift in MS therapy. We have engineered a tolerogenic therapy consisting of spray-dried particles made of a degradable biopolymer, acetalated dextran, and loaded with an antigenic peptide and tolerizing drug, rapamycin (Rapa). After initial characterization and optimization, particles were tested in a myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis model of MS. Representing the earliest possible time of diagnosis, mice were treated at symptom onset in an early therapeutic model, where particles containing MOG and particles containing Rapa+MOG evoked significant reductions in clinical score. Particles were then applied to a highly clinically relevant late therapeutic model during peak disease, where MOG particles and Rapa+MOG particles each elicited a dramatic therapeutic effect, reversing hind limb paralysis and restoring fully functional limbs. To confirm the antigen specificity of our therapy, we immunized mice against the influenza antigen hemagglutinin (HA) and treated them with MOG particles or Rapa+MOG particles. The particles did not suppress antibody responses against HA. Our findings underscore the potential of this particle-based therapy to reverse autoimmunity in disease-relevant models without compromising immune competence, setting it apart from existing treatments.

Protocol for a first-in-human feasibility study of T regulatory cells (TR004) for inflammatory bowel disease using (ex vivo) Treg expansion (TRIBUTE)

INTRODUCTION

Crohn's disease (CD) is a chronic, immune-mediated inflammatory bowel disease (IBD), presenting with symptoms of abdominal pain and bleeding from the gastrointestinal tract. There is no known cure. In vitro-expanded 'thymus-derived' regulatory T cells (tTreg) have shown promise in preclinical models of IBD, leading to interest in their use as a potential therapy in CD. We present a study protocol for a first-in-human study of Tregs for IBD using ex vivo Treg expansion. This study will explore the preliminary safety and tolerability of a single dose of Treg immunotherapy and will inform the design of a subsequent larger trial.

METHODS AND ANALYSIS

Four patients will be recruited from gastroenterology clinics at Guy's and St Thomas' NHS Foundation Trust. Eligible participants are those who are at least 18 years old, have a diagnosis of active moderate to severe CD and have failed to respond to or tolerate at least two prior lines of standard medication. Participants receive a single dose of autologous ex vivo-expanded Tregs and will be followed up to week 21 to collect safety and exploratory efficacy data. Additional safety monitoring will occur at 1 and 2 years post-dose. The primary endpoint is defined as the occurrence of dose-limiting toxicity occurring within 5 weeks post-infusion.

ETHICS AND DISSEMINATION

The study protocol and related documents have been approved by a NHS Research Ethics Committee, the Health Research Authority and the Medicines and Healthcare products Regulatory Agency for Clinical Trial Authorisation. It is intended that the results of the trial will be presented at international conferences and will be submitted for publication in a peer-reviewed scientific journal.

TRIAL REGISTRATION NUMBER

NCT03185000.

Metabolic reprogramming of naïve regulatory T cells by IL-7 and IL-15 promotes their persistence and performance upon adoptive transfer

Tregs for adoptive therapy are traditionally expanded ex vivo using high doses of IL-2. However, the final Treg product has limited survival once infused in patients, potentially affecting therapeutic effectiveness. Here, we tested a novel expansion protocol in which highly purified naïve Tregs were expanded with a combination of IL-7 and IL-15, in the absence of IL-2. The final Treg product was enriched with cells displaying an immature CD45RA+CD62L+CD95+ phenotype, reminiscent of conventional memory stem T cells. The combination of IL-7 and IL-15 confers Tregs a glycolytic metabolism and improved metabolic fitness, characterized by an increased capacity to adapt metabolism according to glucose and oxygen availability. Tregs expanded with IL-7 and IL-15 showed longer persistence and an improved capacity to control xeno-GvHD in NSG mice. This work suggests that metabolic reprogramming induced by IL-7 and IL-15 provides better Treg performance for adoptive therapy.

Current perspectives and the future of disease-modifying therapies in type 1 diabetes

Use of immunomodulating agents to prevent the progression of autoimmune β-cell damage leading to type 1 diabetes mellitus (T1DM) is an interesting area for research. These include non-specific anti-inflammatory agents, immunologic vaccination and anti-inflammatory agents targeting specific immune cells or cytokines. Teplizumab is an anti-CD3-molecule that binds to and leads to the disappearance of the CD3/TCR complex and rendering the T cell anergic to its target antigen. Preclinical and clinical trials have demonstrated its efficacy in reducing the decline in serum C-peptide levels and the need for insulin therapy if used early in the disease process of T1DM. The benefits have been apparent as early as six months to as long as seven years after therapy. It has recently been approved by the Food and Drug Administration to delay the onset of clinical (stage 3) type 1 diabetes in children above 8 years of age. In their recent meta-analysis published in the World Journal of Diabetes, Ma et al found that those in the teplizumab treatment group have a greater likelihood of reduction in insulin use, change in C-peptide response, and better glycemic control compared to the control group with a good safety profile. However, all the included randomized control trials have been conducted in high-income countries. High cost of therapy and unknown utility of the molecule in stage 3 disease limit its widespread use.

CAR-T cell therapy: developments, challenges and expanded applications from cancer to autoimmunity

Chimeric Antigen Receptor (CAR)-T cell therapy has rapidly emerged as a groundbreaking approach in cancer treatment, particularly for hematologic malignancies. However, the application of CAR-T cell therapy in solid tumors remains challenging. This review summarized the development of CAR-T technologies, emphasized the challenges and solutions in CAR-T cell therapy for solid tumors. Also, key innovations were discussed including specialized CAR-T, combination therapies and the novel use of CAR-Treg, CAR-NK and CAR-M cells. Besides, CAR-based cell therapy have extended its reach beyond oncology to autoimmune disorders. We reviewed preclinical experiments and clinical trials involving CAR-T, Car-Treg and CAAR-T cell therapies in various autoimmune diseases. By highlighting these cutting-edge developments, this review underscores the transformative potential of CAR technologies in clinical practice.

Pre-Type 1 Diabetes in Adolescents and Teens: Screening, Nutritional Interventions, Beta-Cell Preservation, and Psychosocial Impacts

Type 1 Diabetes (T1D) is a progressive autoimmune disease often identified in childhood or adolescence, with early stages detectable through pre-diabetic markers such as autoantibodies and subclinical beta-cell dysfunction. The identification of the pre-T1D stage is critical for preventing complications, such as diabetic ketoacidosis, and for enabling timely interventions that may alter disease progression. This review examines the multifaceted approach to managing T1D risk in adolescents and teens, emphasizing early detection, nutritional interventions, beta-cell preservation strategies, and psychosocial support. Screening for T1D-associated autoantibodies offers predictive insight into disease risk, particularly when combined with education and family resources that promote lifestyle adjustments. Although nutritional interventions alone are not capable of preventing T1D, certain lifestyle interventions, such as weight management and specific nutritional choices, have shown the potential to preserve insulin sensitivity, reduce inflammation, and mitigate metabolic strain. Pharmacological strategies, including immune-modulating drugs like teplizumab, alongside emerging regenerative and cell-based therapies, offer the potential to delay disease onset by protecting beta-cell function. The social and psychological impacts of a T1D risk diagnosis are also significant, affecting adolescents' quality of life, family dynamics, and mental health. Supportive interventions, including counseling, cognitive-behavioral therapy (CBT), and group support, are recommended for managing the emotional burden of pre-diabetes. Future directions call for integrating universal or targeted screening programs within schools or primary care, advancing research into nutrition and psychosocial support, and promoting policies that enhance access to preventive resources. Advocacy for the insurance coverage of screening, nutritional counseling, and mental health services is also crucial to support families in managing T1D risk. By addressing these areas, healthcare systems can promote early intervention, improve beta-cell preservation, and support the overall well-being of adolescents at risk of T1D.

Selected Aspects of the Neuroimmunology of Cell Therapies for Neurologic Disease: Perspective

Neurologic disease remains a cause of incalculable suffering, a formidable public health burden, and a wilderness of complex biology and medicine. At the same time, advances in basic science, technology, and the clinical development toolkit bring meaningful benefit for patients along with realistic hope for those whose conditions remain inadequately treated. This perspective focuses on cell-based therapies for neurologic disease, with particular emphasis on neuroimmunologic disorders and on the immunologic considerations of cell therapy for nonimmune conditions. I will consider the use of chimeric antigen receptor (CAR)-T effector cells and regulatory T-cell therapies for autoimmune conditions. I will briefly discuss the immune aspects of pluripotent stem cell (PSC)-derived neuronal therapies. With apologies for the omission, we do not discuss mesenchymal stem cells, glial progenitor cells, or CAR-NK cells, primarily for space limitations.

Cars pick up another passenger: Organ transplantation

With over 30,000 patients having received CAR T cells as a treatment for malignancy, our experience in oncology has facilitated numerous efforts to adapt the CAR therapeutic platform for diseases and conditions beyond cancer. Recognition of their efficacy, where traditional small molecule or biologic therapies fail, has spurred multiple efforts leveraging CAR T cells for immune modulation in the setting of organ/tissue transplantation. In the present review, we discuss CAR T cell approaches that are currently under development, to target both humoral and cellular alloimmunity. These include CAR T platforms repurposed from oncology and autoimmune diseases, as well as ones designed specifically to target alloimmunity in transplant. We also present important challenges and application considerations that will need to be addressed before we can expect successful clinical translation. Finally, we highlight a few of the exciting advances currently in development that are likely to pave a smoother path to translating CAR T cell therapies into transplant patients.

Role of Regulatory T Cells in Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a common cerebrovascular disease that can lead to severe neurological dysfunction in surviving patients, resulting in a heavy burden on patients and their families. When ICH occurs, the blood‒brain barrier is disrupted, thereby promoting immune cell migration into damaged brain tissue. As important immunosuppressive T cells, regulatory T (Treg) cells are involved in the maintenance of immune homeostasis and the suppression of immune responses after ICH. Treg cells mitigate brain tissue damage after ICH in a variety of ways, such as inhibiting the neuroinflammatory response, protecting against blood‒brain barrier damage, reducing oxidative stress damage and promoting nerve repair. In this review, we discuss the changes in Treg cells in ICH clinical patients and experimental animals, the mechanisms by which Treg cells regulate ICH and treatments targeting Treg cells in ICH, aiming to support new therapeutic strategies for clinical treatment.

Conferring alloantigen specificity to regulatory T cells: A comparative analysis of cell preparations undergoing clinical development in transplantation

Conferring alloantigen-specificity to ex vivo expanded CD4+CD25+FOXP3+ regulatory T cells (Tregs) increases their capacity to counteract effector alloimmune responses following adoptive transfer into transplant recipients. Three strategies are currently undergoing clinical development, which involve the following: (1) expanding Tregs in the presence of donor B cells (donor alloantigen-reactive [DAR] Tregs); (2) culturing Tregs with donor cells in the presence of costimulation blockade (CSB-Tregs); and (3) transducing Tregs with an human leukocyte antigen A2-specific chimeric antigen receptor (CAR-Tregs). Our goal in this study was to assess the relative potency of each of these manufactured Treg products both in vitro and in vivo. When compared with polyclonal Tregs, all 3 manufacturing strategies increased the precursor frequency of alloreactive Tregs, and this was proportional to the overall in vitro immunosuppressive properties of the cell products. Accordingly, CAR-Tregs, which contained the highest frequency of donor-reactive Tregs, exhibited the strongest suppressive effects on a cell-per-cell basis. Similarly, in an in vivo mouse model of graft-vs-host disease, infusion of CAR-Tregs conferred a significantly longer recipient survival than any other Treg product. Our results highlighting the alloantigen-reactivity and associated immunosuppressive properties of different manufactured Treg products have implications for the mechanistic interpretation of currently ongoing clinical trials in transplantation.

Changes in Treg cells and cytokines in the peripheral blood of patients with coronary artery disease combined with type 2 diabetes mellitus

BACKGROUND

Patients with coronary artery disease (CAD) combined with type 2 diabetes mellitus (T2DM) develop serious atherosclerotic and diffuse lesions. Inadequate numbers and the dysfunction of CD4+CD25+Foxp3+regulatory T lymphocytes (Treg cells) are common mechanisms underlying the immunopathological damage in CAD and T2DM.

OBJECTIVES

We aimed to explore Treg cell changes in patients with CAD complicated with T2DM and to investigate the association between Treg cells and the severity of CAD.

METHODS

A total of 257 participants were included in the study, divided into a healthy control group (HC, n = 63), CAD group (n = 106), and CAD complicated with T2DM group (CAD+T2DM, n = 88). Flow cytometry detected Treg cell levels, and serum IL-10, IL-6, and ELISA detected TGF-β.

RESULTS

The sample for this study consisted of 170 males and 87 females, with 88 (34.24 %) participants having diabetes and 169 (65.76 %) without diabetes. The proportion of circulating Treg cells was lower in the CAD and CAD+T2DM groups than in the HC group, and it was lower in the CAD+T2DM group than in the CAD group. The plasma levels of IL-10 and TGF-β were lower in the CAD than in the HC group, and the levels in the CAD+T2DM group were significantly lower than those in the CAD group. However, the plasma IL-6 level changed in the opposite direction. Gensini's score was negatively correlated with Treg cells (R = - 0.57, P < .05). Subgroup analyses and interaction analyses showed that the association of Treg with the Gensini score was robust.

CONCLUSION

The level of Treg cells was an independent protective factor for patients with CAD and T2DM and was negatively correlated with the Gensini score. Therefore, Treg cells may be used as therapeutic targets for CAD with T2DM patients.

Belatacept and regulatory T cells in transplantation: synergistic strategies for immune tolerance and graft survival

Calcineurin inhibitors (CNIs) have been a cornerstone in solid organ transplantation for many years; however, their prolonged use is linked to significant adverse effects, most notably nephrotoxicity. Belatacept, a modified version of cytotoxic T lymphocyte antigen-4 immunoglobulin with increased binding affinity for its ligand, has emerged as a viable alternative to traditional CNIs due to its lower toxicity profile. Despite these benefits, belatacept is associated with a higher rate of acute rejection, which presents a challenge for long-term graft survival. This review reevaluates the limitations of belatacept in achieving long-term acceptance of transplants and highlights the importance of regulatory T (Treg) cells in maintaining immune tolerance and preventing graft rejection. Additionally, it discusses the potential benefits of combining therapies that boost Treg cells with belatacept to increase the effectiveness of immunosuppression and improve graft outcomes.

The role of B cells in the pathogenesis of type 1 diabetes

Type 1 diabetes (T1D) is a metabolic disorder caused by a complete lack of insulin, primarily manifested by hyperglycemia. The mechanisms underlying the onset of T1D are complex, involving genetics, environment, and various unknown factors, leading to the infiltration of various immune components into the islets. Besides T cells, B cells are now considered important contributors to the pathogenesis of T1D, according to recent studies. In non-obese diabetic (NOD) mice, the absence of B cells prevents the development of T1D, and B-cell depletion can even restore the function of pancreatic β cells, emphasizing their involvement in the development of T1D. Naturally, besides pathogenic B cells, regulatory B cells (Bregs) might have a protective function in T1D. This article examines the mechanisms behind B-cell tolerance and the defects in B-cell tolerance checkpoints in T1D. We explored possible functions of B cells in T1D, including the role of islet autoantibodies in T1D, T-B cell interactions, and the role of Bregs in the pathogenesis of T1D. We also summarized the advances of B cell-targeted therapy, exploring new methods for intervention and treatment of T1D.

High-affinity chimeric antigen receptor signaling induces an inflammatory program in human regulatory T cells

Regulatory T cells (Tregs) are promising cellular therapies to induce immune tolerance in organ transplantation and autoimmune disease. The success of chimeric antigen receptor (CAR) T cell therapy for cancer has sparked interest in using CARs to generate antigen-specific Tregs. Here, we compared CAR with endogenous T cell receptor (TCR)/CD28 activation in human Tregs. Strikingly, CAR Tregs displayed increased cytotoxicity and diminished suppression of antigen-presenting cells and effector T (Teff) cells compared with TCR/CD28-activated Tregs. RNA sequencing revealed that CAR Tregs activate Teff cell gene programs. Indeed, CAR Tregs secreted high levels of inflammatory cytokines, with a subset of FOXP3+ CAR Tregs uniquely acquiring CD40L surface expression and producing IFN-γ. Interestingly, decreasing CAR antigen affinity reduced Teff cell gene expression and inflammatory cytokine production by CAR Tregs. Our findings showcase the impact of engineered receptor activation on Treg biology and support tailoring CAR constructs to Tregs for maximal therapeutic efficacy.

Synthetic gene circuits drive disease-fighting T cells

Immune cells can be programmed to deliver targeted therapies in models of brain and inflammatory disease.

From promise to practice: CAR T and Treg cell therapies in autoimmunity and other immune-mediated diseases

Autoimmune diseases, characterized by the immune system's attack on the body's own tissues, affect millions of people worldwide. Current treatments, which primarily rely on broad immunosuppression and symptom management, are often associated with significant adverse effects and necessitate lifelong therapy. This review explores the next generation of therapies for immune-mediated diseases, including chimeric antigen receptor (CAR) T cell and regulatory T cell (Treg)-based approaches, which offer the prospect of targeted, durable disease remission. Notably, we highlight the emergence of CD19-targeted CAR T cell therapies, and their ability to drive sustained remission in B cell-mediated autoimmune diseases, suggesting a possible paradigm shift. Further, we discuss the therapeutic potential of Type 1 and FOXP3+ Treg and CAR-Treg cells, which aim to achieve localized immune modulation by targeting their activity to specific tissues or cell types, thereby minimizing the risk of generalized immunosuppression. By examining the latest advances in this rapidly evolving field, we underscore the potential of these innovative cell therapies to address the unmet need for long-term remission and potential tolerance induction in individuals with autoimmune and immune-mediated diseases.

Therapeutic potentials of adoptive cell therapy in immune-mediated neuropathy

Immune-mediated neuropathy (IMN) is a group of heterogenous neuropathies caused by intricate autoimmune responses. For now, known mechanisms of different IMN subtypes involve the production of autoantibodies, complement activation, enhanced inflammation and subsequent axonal/demyelinating nerve damages. Recent therapeutic studies mainly focus on specific antibodies and small molecule inhibitors previously approved in rheumatoid diseases. Initial strategies based on the pathophysiologic features of IMN should be explored. Adoptive cell therapy (ACT) refers to the emerging immunotherapies in which circulating immunocytes are collected from peripheral blood and modified with killing and immunomodulatory capacities. It consists of chimeric antigen receptor-T cell therapy, T cell receptor-engineered T cell, CAR-Natural killer cell therapy, and others. In the last decade, ACT has demonstrated extraordinary potentials in treating cancers, infectious diseases and autoimmune diseases. Versatile combinations of targets, chimeric domains and effector cells greatly empower ACT to treat complicated immune disorders. In this review, we summarized the advances of ACT and envisioned suitable strategies for different IMN subtypes.

Identification of a novel PDC-E2 epitope in primary biliary cholangitis: Application for engineered Treg therapy

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease, characterized by progressive destruction of small intrahepatic bile ducts and portal inflammation. Treatment options are limited, with reliance on liver transplantation in advanced cases. The adaptive immune response is implicated in disease pathogenesis by the presence of anti-mitochondrial antibodies targeting the E2 subunit of the pyruvate dehydrogenase complex (PDC-E2) in 90-95 % of patients and T cells infiltrating the portal tracts. Here, we examined T cell responses to peptides derived from PDC-E2, with a focus on CD4 T cell responses restricted to HLA Class II DRB4∗01:01, an allele found in 62 % of PBC patients, to uncover PDC-E2 epitopes that could be used for engineered regulatory T cell (Treg; EngTreg) therapy. Using an activation-induced marker assay and single cell RNA-sequencing, we found clonal expansion of CD4 T cells reactive to PDC-E2 epitopes among both T conventional (Tconv) and Tregs. Those T cell receptor (TCR) repertoires were non-overlapping and private and included TCRs specific for a novel PDC-E2 epitope restricted to DRB4∗01:01. CD4 Tconv cells reactive to the PDC-E2 novel epitope showed phenotypic heterogeneity skewed towards T follicular helper cells. Using a TCR specific for this novel PDC-E2 epitope, we created an EngTreg that suppressed PDC-E2-specific polyclonal CD4 Tconv cells from PBC patients. This study advances knowledge of PDC-E2-specific T cell responses and introduces a novel PDC-E2 epitope recognized by both Tconv and Tregs. Generation of EngTreg specific for this epitope provides therapeutic potential for PBC.

Exercise, autoimmune diseases and T-regulatory cells

Diverse forms of physical activities contribute to improvement of autoimmune diseases and may prevent disease burst. T regulatory cells (Tregs) maintain tolerance in autoimmune condition. Physical activity is one of the key factors causing enhancement of Tregs number and functions, keeping homeostatic state by its secrotome. Muscles secrete myokines like IL-6, PGC1α (PPARγ coactivator-1 α), myostatin, transforming growth factor β (TGF-β) superfamily), IL-15, brain derived neurotrophic factor (BDNF) and others. The current concept points to the role of exercise in induction of highly functional and stable muscle Treg phenotype. The residing-Tregs require IL6Rα signaling to control muscle function and regeneration. Skeletal muscle Tregs IL-6Rα is a key target for muscle-Tregs cross-talk. Thus, interplay between the Tregs-skeletal muscle, following exercise, contribute to the balance of immune tolerance and autoimmunity. The cargo delivery, in the local environment and periphery, is performed by extracellular vesicles (EVs) secreted by muscle and Tregs, which deliver proteins, lipids and miRNA during persistent exercise protocols. It has been suggested that this ensemble induce protection against autoimmune diseases.

Breaking barriers: advancing cellular therapies in autoimmune disease management

Autoimmune diseases occur due to a dysregulation within the immune system, leading to an aberrant assault on the organism's own tissues. The pathogenesis of these conditions is multifactorial, encompassing intricate interplays among genetic predispositions, environmental determinants, and hormonal fluctuations. The spectrum of autoimmune diseases is broad, impacting a multitude of organ systems, with notable examples such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), multiple sclerosis (MS), psoriasis, and vitiligo. Despite substantial progress in therapeutic interventions over recent years, a definitive cure for autoimmune diseases has yet to be realized, with existing modalities largely providing palliative care. Cellular therapy is considered the fourth pillar in the management of oncological disorders subsequent to surgical resection, radiotherapy, and chemotherapy. Cellular therapies have shown potential in augmenting immune competence and eliminating of targeted neoplastic cells in a spectrum of cancers. As targeting specific molecules on the surface of autoreactive B and T cells, such as CD19, BCMA, CD20, and CTLA-4, cellular therapies are emerging as promising approaches for the treatment of autoimmune diseases. This review delineates the advancements in the application of cellular therapies applied recently for autoimmune diseases and proposes considerations for the advancement of novel therapeutic strategies.