New insights in systemic lupus erythematosus: From regulatory T cells to CAR-T-cell strategies

Cellular therapies in rheumatic and musculoskeletal diseases

A substantial proportion of patients diagnosed with rheumatologic and musculoskeletal diseases (RMDs) exhibit resistance to conventional therapies or experience recurrent symptoms. These diseases, which include autoimmune disorders such as multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus, are marked by the presence of autoreactive B cells that play a critical role in their pathogenesis. The persistence of these autoreactive B cells within lymphatic organs and inflamed tissues impairs the effectiveness of B-cell-depleting monoclonal antibodies like rituximab. A promising therapeutic approach involves using T cells genetically engineered to express chimeric antigen receptors (CARs) that target specific antigens. This strategy has demonstrated efficacy in treating B-cell malignancies by achieving long-term depletion of malignant and normal B cells. Preliminary data from patients with RMDs, particularly those with lupus erythematosus and dermatomyositis, suggest that CAR T-cells targeting CD19 can induce rapid and sustained depletion of circulating B cells, leading to complete clinical and serological responses in cases that were previously unresponsive to conventional therapies. This review will provide an overview of the current state of preclinical and clinical studies on the use of CAR T-cells and other cellular therapies for RMDs. Additionally, it will explore potential future applications of these innovative treatment modalities for managing patients with refractory and recurrent manifestations of these diseases.

mRNA-laden lipid nanoparticle-enabled humanized CD19 CAR-T-cell engineering for the eradication of leukaemic cells

Chimeric antigen receptor T-cell (CAR-T) therapy has shown transformative potential in treating malignant tumours, with increasing global approval of CAR-T products. However, high-production costs and risks associated with viral vector-based CAR-T cells-such as insertional mutagenesis and secondary tumour formation-remain challenges. Our study introduces an innovative CAR-T engineering approach using mRNA delivered via lipid nanoparticles (LNPs), aiming to reduce costs and enhance safety while maintaining strong anti-tumour efficacy. We developed an LNP-based transfection protocol for efficient delivery of mRNA encoding full-human CAR constructs, achieving high CAR expression and significant cytotoxicity against leukaemic cells in vitro. Co-culture with Raji cells showed increased cytokine secretion and tumour cell killing by mRNA-LNP CAR-T cells. Therapeutic efficacy was further demonstrated in an NOD-scid-IL2Rγnull (NSG) mouse model with Raji engraftment, where treated mice exhibited marked tumour regression and extended survival. These findings underscore the potential of mRNA-LNPs as a non-viral, effective CAR-T engineering platform, offering a promising alternative to traditional methods that could improve CAR-T safety, efficacy and accessibility in clinical cancer immunotherapy.

Targeted Cellular Treatment of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease affecting all organ systems. The disease preferentially affects females of childbearing age. It runs a variable course. It may run a mild course that may never lead to severe disease and manifestations from critical organ systems. However, it may also run an undulating course with periods of mild and severe disease. It may run as a mild disease, quickly deteriorating to severe disease and affecting multiple organ systems. Various immune pathways related both to the innate and adaptive immune response are involved in the pathogenesis of SLE. Various drugs have been developed targeting cellular and molecular targets in these pathways. Interferons are involved in the pathogenesis of SLE, and various drugs have been developed to target this pathway. T and B lymphocytes are involved in the pathophysiology of SLE. Various treatment modalities targeting cellular targets are available for the treatment of SLE. These include biologic agents targeting B lymphocytes. However, some patients have disease refractory to these treatment modalities. For these patients, cell-based therapies may be used. Hematopoietic stem cell transplantation involving autologous cells is an option in the treatment of refractory SLE. Mesenchymal stem cells are also applied in the treatment of SLE. Chimeric antigen receptor (CAR)-T cell therapy is a novel treatment also used in SLE management. This novel treatment method holds major promise for the management of autoimmune diseases and, in particular, SLE. Major hurdles to be overcome are the logistics involved, as well as the need for specialized facilities. This review focuses on novel treatment modalities in SLE targeting cellular and molecular targets in the immune system.

IL-10 and IFN-γ as markers for early recognition of pediatric systemic lupus erythematosus complicated with macrophage activation syndrome

OBJECTIVES

To compare the clinical and laboratory characteristics of pediatric-onset systemic lupus erythematosus (pSLE), pSLE with macrophage activation syndrome (MAS), and pSLE with recurrent MAS, and to find biomarkers for the differential diagnosis of these diseases.

METHODS

Demographic, clinical, laboratory and radiological data were analysed for three groups of patients: 18 cases of pSLE with MAS, 48 age- and sex-matched cases of active pSLE without MAS and 40 age- and sex-matched cases of pSLE with inactive disease. One case of a 9-year-old girl with recurrent MAS as the primary manifestation of SLE also was recorded.

RESULTS

IL-10 and IFN-γ levels were significantly higher in pSLE patients with MAS than in pSLE patients without MAS, and were significantly correlated with SLE and MAS laboratory features. Levels of IL-10 > 7.25 pg/ml had a high sensitivity and levels of IFN-γ  > 6.7 pg/ml had a high specificity for predicting MAS in pSLE. Constitutional symptoms were evident in the case of recurrent MAS in pSLE, and traditional immunosuppressive therapies were unable to prevent the next MAS episode.

CONCLUSION

Compared with pSLE and pSLE-MAS with a single episode, pSLE with recurrent MAS has different clinical manifestations and responses to treatment, requiring intensive studies to elucidate the underlying pathogenic mechanisms. Elevated serum levels of IL-10 and IFN-γ may be correlated with pSLE with MAS and can serve as serum biomarkers for pSLE with MAS.

CAR T-cell therapy for systemic lupus erythematosus: current status and future perspectives

Systemic lupus erythematosus (SLE) and lupus nephritis (LN) are debilitating autoimmune disorders characterized by pathological autoantibodies production and immune dysfunction, causing chronic inflammation and multi-organ damage. Despite current treatments with antimalarial drugs, glucocorticoids, immunosuppressants, and monoclonal antibodies, a definitive cure remains elusive, highlighting an urgent need for novel therapeutic strategies. Recent studies indicate that chimeric antigen receptor T-cell (CAR-T) therapy has shown promising results in treating B-cell malignancies and may offer a significant breakthrough for non-malignant conditions like SLE. In this paper, we aim to provide an in-depth analysis of the advancements in CAR-T therapy for SLE, focusing on its potential to revolutionize treatment for this complex disease. We explore the fundamental mechanisms of CAR-T cell action, the rationale for its application in SLE, and the immunological underpinnings of the disease. We also summarize clinical data on the safety and efficacy of anti-CD19 and anti-B cell maturation antigen (BCMA) CAR-T cells in targeting B-cells in SLE. We discuss the clinical implications of these findings and the potential for CAR-T therapy to improve outcomes in severe or refractory SLE cases. The integration of CAR-T therapy into the SLE treatment paradigm presents a new horizon in autoimmunity research and clinical practice. This review underscores the need for continued exploration and optimization of CAR-T strategies to address the unmet needs of SLE patients.

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.

Advances in hematopoietic stem cell transplantation for autoimmune diseases

Autoimmune diseases (ADs) are a collection of immunological disorders in which the immune system responds to self-antigens by producing autoantibodies or self-sensitized cells. Current treatments are unable to cure ADs, and achieving long-term drug-free remission remains a challenging task. Hematopoietic stem cell transplantation (HSCT) stands out from other therapies by specifically targeting ADs that target various cell subpopulations, demonstrating notable therapeutic benefits and resulting in sustained drug-free remission. Since different ADs have distinct mechanisms of action, the comprehensive understanding of how HSCT works in treating ADs is crucial. This review provides a detailed overview of the latest research and clinical applications of HSCT in treating ADs, offering new insights for clinicians aiming to optimize its use for ADs management.

The Role of Chimeric Antigen Receptor T-Cell Therapy in Immune-Mediated Neurological Diseases

Despite the use of 'high efficacy' disease-modifying therapies, disease activity and clinical progression of different immune-mediated neurological diseases continue for some patients, resulting in accumulating disability, deteriorating social and mental health, and high economic cost to patients and society. Although autologous hematopoietic stem cell transplant is an effective treatment modality, it is an intensive chemotherapy-based therapy with a range of short- and long-term side-effects. Chimeric antigen receptor T-cell therapy (CAR-T) has revolutionized the treatment of B-cell and other hematological malignancies, conferring long-term remission for otherwise refractory diseases. However, the toxicity of this treatment, particularly cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome, and the complexity of production necessitate the need for a high level of specialization at treating centers. Early-phase trials of CAR-T therapies in immune-mediated B cell driven conditions, such as systemic lupus erythematosus, neuromyelitis optica spectrum disorder and myasthenia gravis, have shown dramatic clinical response with few adverse events. Based on the common physiopathology, CAR-T therapy in other immune-mediated neurological disease, including multiple sclerosis, chronic inflammatory polyradiculopathy, autoimmune encephalitis, and stiff person syndrome, might be an effective option for patients, avoiding the need for long-term immunosuppressant medications. It may prove to be a more selective immunoablative approach than autologous hematopoietic stem cell transplant, with potentially increased efficacy and lower adverse events. In this review, we present the state of the art and future directions of the use of CAR-T in such conditions. ANN NEUROL 2024;96:441-452.

CAR-T cell therapy: a game-changer in cancer treatment and beyond

In recent years, cancer has become one of the primary causes of mortality, approximately 10 million deaths worldwide each year. The most advanced, chimeric antigen receptor (CAR) T cell immunotherapy has turned out as a promising treatment for cancer. CAR-T cell therapy involves the genetic modification of T cells obtained from the patient's blood, and infusion back to the patients. CAR-T cell immunotherapy has led to a significant improvement in the remission rates of hematological cancers. CAR-T cell therapy presently limited to hematological cancers, there are ongoing efforts to develop additional CAR constructs such as bispecific CAR, tandem CAR, inhibitory CAR, combined antigens, CRISPR gene-editing, and nanoparticle delivery. With these advancements, CAR-T cell therapy holds promise concerning potential to improve upon traditional cancer treatments such as chemotherapy and radiation while reducing associated toxicities. This review covers recent advances and advantages of CAR-T cell immunotherapy.

Spectrum of Treg and self-reactive T cells: single cell perspectives from old friend HTLV-1

Despite extensive regulatory T cell (Treg) research, fundamental questions on in vivo dynamics remain to be answered. The current study aims to dissect several interwoven concepts in Treg biology, highlighting the 'self-reactivity' of Treg and their counterparts, namely naturally-arising memory-phenotype T-cells, as a key mechanism to be exploited by a human retroviral infection. We propose the novel key concept, Periodic T cell receptor (TCR)-signalled T-cells, capturing self-reactivity in a quantifiable manner using the Nr4a3-Timer-of-cell-kinetics-and-activity (Tocky) technology. Periodic and brief TCR signals in self-reactive T-cells contrast with acute TCR signals during inflammation. Thus, we propose a new two-axis model for T-cell activation by the two types of TCR signals or antigen recognition, elucidating how Foxp3 expression and acute TCR signals actively regulate Periodic TCR-signalled T-cells. Next, we highlight an underappreciated branch of immunological research on Human T-cell Leukemia Virus type 1 (HTLV-1) that precedes Treg studies, illuminating the missing link between the viral infection, CD25, and Foxp3. Based on evidence by single-cell analysis, we show how the viral infection exploits the regulatory mechanisms for T-cell activation and suggests a potential role of periodic TCR signalling in infection and malignant transformation. In conclusion, the new perspectives and models in this study provide a working framework for investigating Treg within the self-reactive T-cell spectrum, expected to advance understanding of HTLV-1 infection, cancer, and immunotherapy strategies for these conditions.

CAR T treatment beyond cancer: Hope for immunomodulatory therapy of non-cancerous diseases

Engineering a patient's own T cells to accurately identify and eliminate cancer cells has effectively cured individuals afflicted with previously incurable hematologic cancers. These findings have stimulated research into employing chimeric antigen receptor (CAR) T therapy across various areas within the field of oncology. However, evidence from both clinical and preclinical investigations emphasize the broader potential of CAR T therapy, extending beyond oncology to address autoimmune disorders, persistent infections, cardiac fibrosis, age-related ailments and other conditions. Concurrently, the advent of novel technologies and platforms presents additional avenues for utilizing CAR T therapy in non-cancerous contexts. This review provides an overview of the rationale behind CAR T therapy, delineates ongoing challenges in its application to cancer treatment, summarizes recent findings in non-cancerous diseases, and engages in discourse regarding emerging technologies that bear relevance. The review delves into prospective applications of this therapeutic approach across a diverse range of scenarios. Lastly, the review underscores concerns related to precision and safety, while also outlining the envisioned trajectory for extending CAR T therapy beyond cancer treatment.

CD19 Chimeric Antigen Receptor (CAR) T-Cell Therapy for Systemic Autoimmune Diseases

A small number of drugs have been the sole stay of conventional treatment for autoimmune illnesses for the past 10 years. These medications have a number of side effects that restrict their usage and necessitate continuous administration to keep a patient in a state of remission. While many new treatments are being researched to address this problem, chimeric antigen receptor (CAR) T-cell therapy currently shows the greatest potential. Current medical guidelines do not currently advocate the use of this medicine because it is still in its early stages of development due to continuing clinical research. Therefore, the aim of this systematic review was to determine what new findings have been reported in recent studies about the safety and efficacy of CAR T-cells. From the nine studies collected in total, it was found that systemic lupus erythematosus (SLE) was the most often researched autoimmune disease. The CAR T-cell therapy had noticeable results after one to two months on average. The most frequent adverse effect was cytokine release syndrome (CRS), which was treated cautiously and infrequently necessitated extensive intervention. All serological tests showed improvement, and clinical remission was always achieved. This review concludes that, due to the one-time infusion and low adverse reaction rate, the therapy not only outperforms conventional drugs but is also more practical. There is even more cause to look forward to the full deployment of this innovative therapeutic alternative, as variations of the therapy are currently being explored.

Peripheral helper T cells in human diseases

Peripheral helper T cells (Tph) are a specialized subset of CD4+ T cells with the ability to help B cells and induce antibody production. Although usually located in ectopic lymphoid-like structures (ELS), inside the peripheral blood, Tph cells can also be identified. The aberrant proliferation and functions of Tph cells are commonly found in the patients with disease. In this review, first we will summarize the biological characteristics of Tph cells, such as the expression of surface molecules, transcription factors and cytokines, and discuss its B cell help functions. Tph cells also have roles in a wide range of human diseases, including autoimmune diseases, infectious diseases, malignancies etc. Therefore, there is a strong interest in targeting Tph cells to improve treat strategies of human diseases.

Innovative cellular therapies for autoimmune diseases: expert-based position statement and clinical practice recommendations from the EBMT practice harmonization and guidelines committee

Autoimmune diseases (ADs) are characterized by loss of immune tolerance, high chronicity, with substantial morbidity and mortality, despite conventional immunosuppression (IS) or targeted disease modifying therapies (DMTs), which usually require repeated administration. Recently, novel cellular therapies (CT), including mesenchymal stromal cells (MSC), Chimeric Antigen Receptors T cells (CART) and regulatory T cells (Tregs), have been successfully adopted in ADs. An international expert panel of the European Society for Blood and Marrow Transplantation and the International Society for the Cell and Gene Therapy, reviewed all available evidence, based on the current literature and expert practices, on use of MSC, CART and Tregs, in AD patients with rheumatological, neurological, and gastroenterological indications. Expert-based consensus and recommendations for best practice and quality of patient care were developed to support clinicians, scientists, and their multidisciplinary teams, as well as patients and care providers and will be regularly updated.

Multilayer concept of autoimmune mechanisms and manifestations in inborn errors of immunity: Relevance for precision therapy

Autoimmunity in inborn errors of immunity (IEIs) has a multifactorial pathogenesis and develops subsequent to a genetic predisposition in conjunction with gene regulation, environmental modifiers, and infectious triggers. On the basis of incremental data availability owing to upfront application of omics technologies, a more granular and dynamic view of mechanisms and manifestations is warranted. Here, we present a comprehensive novel concept of autoimmunity in IEIs that considers multiple layers of interdependent elements and connects 101 causative genes or deletions according to the quality of the allelic variants with 47 molecular pathways and 22 immune effector mechanisms. Furthermore, we list 50 resulting manifestations together with the corresponding Human Phenotype Ontology terms and review the types and frequencies of the most relevant clinical presentations. When all of its elements are taken together, this concept (1) extends the historical anatomic view of central versus peripheral tolerance toward multiple interdependent mechanisms of immune tolerance, (2) delineates the mechanisms underlying the protean clinical manifestations, and thereby, (3) points toward the most suitable precision therapy for autoimmunity in IEIs. The multilayer concept of autoimmune mechanisms and manifestations in IEIs will facilitate research design and provide clinical guidance on the use of precision medicine irrespective of the data depth available in each health care scenario.

Pathogenesis and novel therapeutics of regulatory T cell subsets and interleukin-2 therapy in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a heterogeneous multisystem inflammatory disease with wide variability in clinical manifestations. Natural arising CD4+ regulatory T cells (Tregs) play a critical role in maintaining peripheral tolerance by suppressing inflammation and preventing autoimmune responses in SLE. Additionally, CD8+ regulatory T cells, type 1 regulatory T cells (Tr1), and B regulatory cells also have a less well-defined role in the pathogenesis of SLE. Elucidation of the roles of various Treg subsets dedicated to immune homeostasis will provide a novel therapeutic approach that governs immune tolerance for the remission of active lupus. Diminished interleukin (IL)-2 production is associated with a depleted Treg cell population, and its reversibility by IL-2 therapy provides important reasons for the treatment of lupus. This review focuses on the pathogenesis and new therapeutics of human Treg subsets and low-dose IL-2 therapy in clinical benefits with SLE.

New cell sources for CAR-based immunotherapy

Chimeric antigen receptor (CAR) T cell therapy, in which a patient's own T lymphocytes are engineered to recognize and kill cancer cells, has achieved striking success in some hematological malignancies in preclinical and clinical trials, resulting in six FDA-approved CAR-T products currently available in the market. Despite impressive clinical outcomes, concerns about treatment failure associated with low efficacy or high cytotoxicity of CAR-T cells remain. While the main focus has been on improving CAR-T cells, exploring alternative cellular sources for CAR generation has garnered growing interest. In the current review, we comprehensively evaluated other cell sources rather than conventional T cells for CAR generation.

Cellular-Based Therapies in Systemic Sclerosis: From Hematopoietic Stem Cell Transplant to Innovative Approaches

Systemic sclerosis (SSc) is a systemic disease characterized by autoimmune responses, vasculopathy and tissue fibrosis. The pathogenic mechanisms involve a wide range of cells and soluble factors. The complexity of interactions leads to heterogeneous clinical features in terms of the extent, severity, and rate of progression of skin fibrosis and internal organ involvement. Available disease-modifying drugs have only modest effects on halting disease progression and may be associated with significant side effects. Therefore, cellular therapies have been developed aiming at the restoration of immunologic self-tolerance in order to provide durable remissions or to foster tissue regeneration. Currently, SSc is recommended as the 'standard indication' for autologous hematopoietic stem cell transplantation by the European Society for Blood and Marrow Transplantation. This review provides an overview on cellular therapies in SSc, from pre-clinical models to clinical applications, opening towards more advanced cellular therapies, such as mesenchymal stem cells, regulatory T cells and potentially CAR-T-cell therapies.