B cell depletion therapies in autoimmune diseases: Monoclonal antibodies or chimeric antigen receptor-based therapy?

Heterohybridomas producing human immunoglobulin light chains using CD138-selected bone marrow cells

Background

Light chain research is hampered by lack of mammalian cell lines producing human light chains (FLC). Therefore, we used heterohybridoma (HH) technology to produce clones making FLC thereby providing tools to study light chain behavior.

Methods

Marrow CD138+ cells from patients with multiple myeloma (MM) and polyclonal gammopathy (PG) were selected, fused with B5-6 T cells and cultured in hypoxanthine-aminopterin-thymidine medium (HAT). HH clones were selected based on ELISA for human immunoglobulins and flow cytometry for intracellular (IC) FLC. We compared marrow cell counts and HH yields by diagnosis, evaluated clones making only FLC by flow and by dimer/monomer (D/M) ratios in vitro and in vivo, and sequenced FLC genes with RT-PCR.

Results

Marrows from 13 patients with active disease, 10 MM and 3 PG, were no different in mononuclear or CD138-selected cell counts. HH FLC clones (7 λ, 1 κ) were obtained from 5/10 MM and 2/3 PG; one PG case produced 2 HH FLC clones (one λ and one κ). Of the 10 MM cases, 8 had high risk cytogenetic features and 4 of the 8 produced HH clones while of the 3 PG cases 2 had negative cytogenetics and 1 had loss of IgH identified and produced an HH clone. Mononuclear (MNC) and CD138-selected cell numbers were markedly higher in the samples that enabled productive fusions. Median MFI for the 8 HH clones by IC flow for FLC was 9849 (range, 5344-27451) and median percentage of cells IC positive was 88 % (69-95). Medians of in vitro and in vivo FLC production were 47 μg/mL (9-80) per million cells after 2 days of culture and 66.4 μg/mL (16-1100) in NOD-SCID γ (NSG) mice 14 days after intraperitoneal (IP) implants of 2 × 106 HH cells. Dimer/monomer ratio medians were 0.575 (0.08-0.939) in vitro and 0.91 (0.82-2.7) in vivo, values that were correlated (R2 = 0.565) by two-tailed paired t-test with P < 0.05.

Conclusions

B5-6 T HH producing human FLC were obtained from 50 % of MM and PG cases. High numbers of MNC and CD138+ cells enabled productive fusions. The HH clones produced FLC with easily appreciated dimers and monomers in vitro and in vivo. With IP in vivo implants after 2 weeks more dimers were seen than in short term cultures in vitro. These HH clones will be made available for study of FLC metabolism and testing of therapeutics designed to abrogate FLC production or enable FLC clearance in vivo.

CD19+ B cell depletion: a novel strategy to alleviate ischemic stroke damage

Background

Ischemic stroke, accounting for approximately 80% of all stroke cases, is a major public health challenge and a leading cause of death and disability worldwide. Current treatments primarily involve thrombolytic therapy, limited to a 4.5-hour window due to the risk of complications, underscoring the need for new therapeutic targets. Systemic inflammation plays a critical role in stroke progression, with immune cells infiltrating the brain and exacerbating damage. B cells, in particular, have been implicated in stroke pathogenesis, although their exact role remains contentious. This study examines anti-CD19 antibody (aCD19 Ab) treatment in a stroke model to determine if CD19+ B cell depletion can reduce infarct size and alleviate inflammation.

Results

This study investigated whether temporary inhibition of B-cell activity using an aCD19 Ab could alleviate ischemic brain injury in a stroke mouse model by regulating cerebral and systemic immune reactions. Mice subjected to middle cerebral artery occlusion (MCAO) exhibited significant reductions in infarct size and brain edema, prolonged post-MCAO survival, and improved behavioral outcomes following aCD19 Ab treatment. Transmission electron microscopy (TEM) and Computed Tomography Angiography (CTA) results revealed a reduction in microvascular endothelial edema, decreased mitochondrial damage in neurons, reduced neuronal apoptosis, and a favorable reconstruction of the cerebral vascular network. Additionally, B cell inhibition reduced pro-inflammatory cytokines and immune cells in the brain and peripheral circulation. The immune response alterations observed in the MCAO/R group were consistent with the trends indicated by stroke patient data.

Conclusions

Temporary inhibition of B-cell activity via aCD19 antibody injection alleviated ischemic brain injury in a mouse model of stroke by suppressing systemic immune reactions. Changes in immune cells within the meninges may play a role, and further investigation is needed to understand the mechanisms involved. These findings suggest that cerebral and systemic immune responses contribute to the pathogenesis of ischemic stroke, and temporary B cell depletion may represent a potential therapeutic target for stroke therapy.

A new therapeutic pathway in autoimmune diseases: chimeric antigen receptor T cells (CAR-T) targeting specific cell subtypes or antigen-specific B lymphocytes—a brief review

In hematological malignancies, autologous immunotherapy with T lymphocytes expressing a chimeric antigen receptor (CAR-T) has been successfully applied. CAR enhances the immuno-cellular effector system directly against cells expressing target antigens. The objective here was to discuss the prospects of applying CAR-T and its variants in autoimmune diseases (AIDs) to deplete pathogenic autoantibodies by eliminating B lymphocytes and plasma cells. B cells play a crucial role in the pathogenesis of AID through the production of autoantibodies, cytokine dysregulation, antigen presentation, and regulatory dysfunction. In AID with numerous autoreactive clones against various autoantigens, such as systemic lupus erythematosus, rheumatoid arthritis, vasculitis, myositis, and systemic sclerosis, CAR-T targeting CD19/CD20 and B-cell maturation antigen (BCMA) have shown success in preclinical and clinical studies, representing an innovative option for refractory patients when standard treatments fail. The suppression of B lymphocytes reactive against specific antigens using cytolytic T cells carrying a chimeric autoantibody receptor (CAAR-T) offers a promising approach for managing various AIDs, especially those with characterized pathogenic autoantibodies, such as pemphigus vulgaris, myasthenia gravis, and anti-NMDAR autoimmune encephalitis. CAAR-T allows the elimination of autoreactive B lymphocytes without compromising the general functionality of the immune system, minimizing common side effects in general immunosuppressive therapies, including immunobiologicals and CAR-T. In vitro, preclinical, and clinical (phase 1) studies have demonstrated the efficacy and specificity of CAR-T and CAAR-T in several AIDs; however, extensive clinical trials (phase 3) are required to assess their safety and clinical applicability. These advances promise to enhance precision medicine in the management of AIDs, offering personalized treatments for individual patients.

CXCR4 Inhibition Enhances the Efficacy of CD19 Monoclonal Antibody-Mediated Extermination of B-Cell Lymphoma

CD19 and CXCR4 are pivotal regulators of B-cell activation and migration, respectively. Specifically, CXCR4 signaling critically influences the dissemination of various malignant B cells through constitutive activation and aberrant expression. This study explores the interaction between CD19 and CXCR4 signaling in the context of B-cell lymphomas, particularly focusing on diffuse large B-cell lymphoma (DLBCL) and Waldenström Macroglobulinemia (WM). We assessed the roles of CD19 in survival and CXCL12-induced migration by using knockout (KO) cells of DLBCL and WM origin alongside evaluating the impact of CD19 monoclonal antibodies (mAbs) on antibody-dependent cell-mediated cytotoxicity (ADCC). Our results highlight that CD19 is important for survival and CXCL12-induced migration, and mAbs variably increase CXCL12-induced migration and enhance ADCC. Additionally, we demonstrate that the endogenous peptide inhibitor of the CXCR4 (EPI-X4) derivative JM#21 effectively inhibits CD19-mediated migration enhancement and promotes ADCC, thereby augmenting the therapeutic efficacy of CD19 mAb-based immunotherapy in lymphoma models. Our study underscores the potential of targeting both CD19 and CXCR4 to refine therapeutic strategies for treating B-cell malignancies, suggesting a synergistic approach could improve clinical outcomes in WM treatment.

Six events that shaped antibody approvals in oncology

A little over twenty-five years ago, the European Medicines Agency (EMA) and the Food and Drug Administration (FDA) approved the chimeric antibody rituximab which fundamentally altered the landscape of anti-cancer drugs. While only a few antibodies were approved in the immediate years that followed the rituximab approval, the last decade saw a wave of antibody-drug approvals in the oncology arena. In the last three years, the EMA and FDA greenlighted eighteen antibodies, the majority of them designed in the formats of antibody-drug conjugates (ADC) and bispecific antibodies (BsAb). While the use of ADC and BsAb formats and the current rapid pace of approvals appear routine and almost inevitable, such progress was thought to be quite improbable in the early days of therapeutic antibody development. To understand how we arrived at the current state of antibody development in oncology, we focus on six monumental events that shaped antibody approvals over the last two and half decades. We examine the circumstances that led to the approval of rituximab and trastuzumab, the first successful antibodies for the treatment of hematologic and solid cancers. We detail the generation of the ADC and BsAb formats that dramatically augmented antibody-mediated precision cytotoxicity. Finally, we explore the development of ipilimumab, the first immune checkpoint-inhibiting antibody that activates the immune system to kill cancer cells, and the discovery that allowed the use of checkpoint inhibitors across all cancer types based on the presence of genetic markers. Revisiting these key events provides critical insights into the process of antibody development in oncology.

Autoimmunity in Cardiomyopathy-Induced Heart Failure and Cardiac Autoantibody Removal by Immunoadsorption

There is increasing evidence that β1-adrenoreceptor autoantibody (β1AR-AAb) elimination can break the vicious circle induced by certain pathological conditions associated with alteration of the physiological self-tolerance, followed by generation of such AAbs and activation of cell-mediated immune processes directed against the myocardium. Concerning this, the present narrative review article provides an updated overview of the state of knowledge about the role of auto-immunity in the etiopathogenesis of cardiomyopathies, with a particular focus on immunoadsorption (IA) therapy for β1AR-AAb-positive adult patients with a dilated cardiomyopathy (DCM)-associated refractory heart failure (HF). Among many relevant findings, the increasing prevalence (up to 97%) of β1AR-AAb-positive patients related to the aggravation of HF, the high prevalence (between 84% and 91%) of HF patients in which IA can reduce to a minimum any increased β1AR-AAb level, as well as the high prevalence (about 80%) of responders to the IA-induced normalization of β1AR-AAb levels by long-term improvement in LV ejection fraction with increase in LV stroke volume and cardiac output, are of particular relevance. Given that after the elimination of β1AR-AAbs in potential candidates for heart transplantation (HTx), the post-IA 3- and 5-year HTx-/mechanical support-free survival probability reached 80% and 63-69%, respectively, the good tolerability of IA and the possibility to repeat that therapy also in elderly persons strongly suggest that in appropriately selected patients, this therapy deserves much more attention in the future.

Mechanistic Evaluation of Anti-CD19 CAR-T Cell Therapy Repurposed in Systemic Lupus Erythematosus Using a Quantitative Systems Pharmacology Model

CAR-T cell therapy, renowned for its success in oncology, is now venturing into the realm of B cell-mediated autoimmune diseases. Recent observations have revealed significant pharmacological effects of CD19 CAR-T cells in patients with systemic lupus erythematosus (SLE), suggesting promising applications in other autoimmune conditions. Consequently, as of December 2024, there are 116 different clinical trials evaluating CAR-T cells against autoimmune conditions. While the field is starting to understand the overall pharmacological actions of CAR-T cells in autoimmune diseases, the dose-exposure-response relationship remains inadequately characterized due to limited clinical data. To address these uncertainties, we have developed a Quantitative Systems Pharmacology (QSP) model using short-term limited clinical data of anti-CD19 CAR-Ts in autoimmune disease patients (n = 5), followed by a model qualification step utilizing an external dataset (n = 13). The developed QSP model integrated and effectively characterized the (1) cellular kinetics of different immunophenotypic population of CAR-T cells, (2) impact of lymphodepletion chemotherapy on host immune cells, (3) CAR-mediated elimination of CD19+ B-cells and (4) dynamic changes in disease surrogate biomarkers and its relationship with clinical score. The key pharmacological biomarkers which were incorporated within the QSP model included anti double stranded DNA (anti-dsDNA) antibodies, proteinuria, C3 protein and IFN-alpha. Later, a linear regression analysis-based relationship was developed between continuous disease biomarkers and the categorical SLE disease activity index (SLE-DAI) determined by the investigators offering a predictive framework for disease progression in SLE patients. This proposed QSP model holds potential to elucidate quantitative pharmacology and expedite clinical advancement of autologous and allogeneic cell therapies in autoimmune diseases.

Unlocking Transplant Tolerance with Biomaterials

For patients suffering from organ failure due to injury or autoimmune disease, allogeneic organ transplantation with chronic immunosuppression is considered the god standard in terms of clinical treatment. However, the true "holy grail" of transplant immunology is operational tolerance, in which the recipient exhibits a sustained lack of alloreactivity toward unencountered antigen presented by the donor graft. This outcome is resultant from critical changes to the phenotype and genotype of the immune repertoire predicated by the activation of specific signaling pathways responsive to soluble and mechanosensitive cues. Biomaterials have emerged as a medium for interfacing with and reprogramming these endogenous pathways toward tolerance in precise, minimally invasive, and spatiotemporally defined manners. By viewing seminal and contemporary breakthroughs in transplant tolerance induction through the lens of biomaterials-mediated immunomodulation strategies-which include intrinsic material immunogenicity, the depot effect, graft coatings, induction and delivery of tolerogenic immune cells, biomimicry of tolerogenic immune cells, and in situ reprogramming-this review emphasizes the stunning diversity of approaches in the field and spotlights exciting future directions for research to come.

Juvenile Dermatomyositis: Updates in Pathogenesis and Biomarkers, Current Treatment, and Emerging Targeted Therapies

Juvenile dermatomyositis is a rare systemic inflammatory autoimmune disease involving muscle, skin, and vessels. Most patients do not fully respond to initial therapy, instead having a chronic refractory or polycyclic disease course. Pathogenesis is not completely understood, but immune cell dysregulation, particularly of B cells, mitochondrial dysfunction, changes in neutrophils and neutrophil extracellular traps (NETs), and increased type I and type II interferon (IFN) signaling have been described. There are limited randomized controlled trials of drugs in juvenile dermatomyositis (JDM), and treatment is largely based on lower-quality data such as case series, retrospective studies, and open-label prospective studies. These data have been compiled into expert recommendations or consensus treatment plans, which help guide therapy. While initial therapy is more standard with most including corticosteroids (high-dose oral and/or pulse intravenous methylprednisolone) and methotrexate, for refractory patients, guidelines are more varied with multiple options or combinations, including biologic therapies. There is a clear need for more efficacious and personalized therapy in JDM. Emerging treatment options worthy of further study in JDM include targeting IFN-signaling (JAK, IFNAR1, IFN beta), B-cells (CD20, CD19, BAFF, TACI, CD38, BCMA) including Chimeric Antigen Receptor (CAR)-T cell therapy, mitochondrial dysfunction, and NETs.

Ocular immune-related diseases: molecular mechanisms and therapy

Ocular immune-related diseases, represent a spectrum of conditions driven by immune system dysregulation, include but not limit to uveitis, diabetic retinopathy, age-related macular degeneration, Graves' ophthalmopathy, etc. The molecular and cellular mechanisms underlying these diseases are typically dysfunctioned immune responses targeting ocular tissues, resulting in inflammation and tissue damage. Recent advances have further elucidated the pivotal role of different immune responses in the development, progression, as well as management of various ocular immune diseases. However, there is currently a relative lack of connection between the cellular mechanisms and treatments of several immune-related ocular diseases. In this review, we discuss recent findings related to the immunopathogenesis of above-mentioned diseases. In particular, we summarize the different types of immune cells, inflammatory mediators, and associated signaling pathways that are involved in the pathophysiology of above-mentioned ophthalmopathies. Furthermore, we also discuss the future directions of utilizing anti-inflammatory regime in the management of these diseases. This will facilitate a better understanding of the pathogenesis of immune-related ocular diseases and provide new insights for future treatment approaches.

Advances in CAR-T therapy for central nervous system tumors

The application of chimeric antigen receptor T-cell therapy in central nervous system tumors has significantly advanced; however, challenges pertaining to the blood-brain barrier, immunosuppressive microenvironment, and antigenic heterogeneity continue to be encountered, unlike its success in hematological malignancies such as acute lymphoblastic leukemia and diffuse large B-cell lymphomas. This review examined the research progress of chimeric antigen receptor T-cell therapy in gliomas, medulloblastomas, and lymphohematopoietic tumors of the central nervous system, focusing on chimeric antigen receptor T-cells targeting antigens such as EGFRvIII, HER2, B7H3, GD2, and CD19 in preclinical and clinical studies. It synthesized current research findings to offer valuable insights for future chimeric antigen receptor T-cell therapeutic strategies for central nervous system tumors and advance the development and application of this therapeutic modality in this domain.

Monoclonal antibodies: From magic bullet to precision weapon

Monoclonal antibodies (mAbs) are used to prevent, detect, and treat a broad spectrum of non-communicable and communicable diseases. Over the past few years, the market for mAbs has grown exponentially with an expected compound annual growth rate (CAGR) of 11.07% from 2024 (237.64 billion USD estimated at the end of 2023) to 2033 (679.03 billion USD expected by the end of 2033). Ever since the advent of hybridoma technology introduced in 1975, antibody-based therapeutics were realized using murine antibodies which further progressed into humanized and fully human antibodies, reducing the risk of immunogenicity. Some benefits of using mAbs over conventional drugs include a drastic reduction in the chances of adverse reactions, interactions between drugs, and targeting specific proteins. While antibodies are very efficient, their higher production costs impede the process of commercialization. However, their cost factor has been improved by developing biosimilar antibodies as affordable versions of therapeutic antibodies. Along with the recent advancements and innovations in antibody engineering have helped and will furtherly help to design bio-better antibodies with improved efficacy than the conventional ones. These novel mAb-based therapeutics are set to revolutionize existing drug therapies targeting a wide spectrum of diseases, thereby meeting several unmet medical needs. This review provides comprehensive insights into the current fundamental landscape of mAbs development and applications and the key factors influencing the future projections, advancement, and incorporation of such promising immunotherapeutic candidates as a confrontation approach against a wide list of diseases, with a rationalistic mentioning of any limitations facing this field.

Cutting-edge approaches to B-cell depletion in autoimmune diseases

B-cell depletion therapy (BCDT) has been employed to treat autoimmune disease for ~20 years. Immunoglobulin G1 (IgG1) monoclonal antibodies targeting CD20 and utilizing effector function (eg, antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, antibody-dependent cellular phagocytosis) to eliminate B cells have historically been the predominant therapeutic approaches. More recently, diverse BCDT approaches targeting a variety of B-cell surface antigens have been developed for use in hematologic malignancies, including effector-function-enhanced monoclonal antibodies, chimeric antigen receptor T-cell (CAR-T) treatment, and bispecific T-cell engagers (TCEs). The latter category of antibodies employs CD3 engagement to augment the killing of target cells. Given the improvement in B-cell depletion observed with CAR-T and TCEs compared with conventional monospecific antibodies for treatment of hematologic malignancies and the recent case reports demonstrating therapeutic benefit of CAR-T in autoimmune disease, there is potential for these mechanisms to be effective for B-cell-mediated autoimmune disease. In this review, we discuss the various BCDTs that are being developed in autoimmune diseases, describing the molecule designs, depletion mechanisms, and potential advantages and disadvantages of each approach as they pertain to safety, efficacy, and patient experience. Additionally, recent advances and strategies with TCEs are presented to help broaden understanding of the potential for bispecific antibodies to safely and effectively engage T cells for deep B-cell depletion in autoimmune diseases.

Immune system dysregulation in the pathogenesis of non-alcoholic steatohepatitis: unveiling the critical role of T and B lymphocytes

Non-alcoholic fatty liver disease (NAFLD), characterized by the excessive accumulation of fat within the cytoplasm of hepatocytes (exceeding 5% of liver weight) in individuals without significant alcohol consumption, has rapidly evolved into a pressing global health issue, affecting approximately 25% of the world population. This condition, closely associated with obesity, type 2 diabetes, and the metabolic syndrome, encompasses a spectrum of liver disorders ranging from simple steatosis without inflammation to non-alcoholic steatohepatitis (NASH) and cirrhotic liver disease. Recent research has illuminated the complex interplay between metabolic and immune responses in the pathogenesis of NASH, underscoring the critical role played by T and B lymphocytes. These immune cells not only contribute to necroinflammatory changes in hepatic lobules but may also drive the onset and progression of liver fibrosis. This narrative review aims to provide a comprehensive exploration of the effector mechanisms employed by T cells, B cells, and their respective subpopulations in the pathogenesis of NASH. Understanding the immunological complexity of NASH holds profound implications for the development of targeted immunotherapeutic strategies to combat this increasingly prevalent and burdensome metabolic liver disease.

Impact of Rituximab on Remission Rates in Granulomatosis With Polyangiitis: A Systematic Review

This systematic review evaluates the efficacy of rituximab in inducing and maintaining remission in patients with granulomatosis with polyangiitis (GPA). We conducted a comprehensive search across multiple databases, identifying 81 studies, of which 11 met our inclusion criteria after rigorous screening and assessment for relevance and quality. Our analysis shows that rituximab, compared to traditional treatments such as cyclophosphamide and azathioprine, significantly improves remission rates and reduces relapse frequency in GPA patients. Notably, rituximab's benefits extend across various patient demographics, including pediatric groups, and are evident in different dosing regimens, highlighting its versatility and potential as a first-line therapy. The review also underscores the importance of personalized medicine approaches in managing GPA, as rituximab's effectiveness was particularly pronounced in patients with relapsing disease forms. Future research should focus on long-term outcomes, optimal dosing strategies, and the economic implications of widespread rituximab use in clinical practice. Our findings advocate for the integration of rituximab into standard treatment protocols for GPA, offering new hope for patients afflicted with this challenging autoimmune disorder.

Circumventing B Cell Responses to Allow for Redosing of Adeno-Associated Virus Vectors

Adeno-associated virus (AAV)-mediated gene therapy has made significant progress in the last few decades. Nevertheless, challenges imposed by the immune system remain. The very high doses of AAV vectors used for some disorders have resulted in serious adverse events (SAEs) or even deaths, demonstrating that AAV vector doses that can safely be injected into patients are limited and for some indications below the therapeutic dose. Currently used immunosuppressive drugs have not prevented the SAEs, indicating that it may be prudent to treat patients with repeated transfer of moderate doses rather than a single injection of high doses of AAV vectors. The former approach has been avoided as AAV vectors elicit neutralizing antibodies that prevent successful reapplication of serologically crossreactive vectors. Immunosuppressive regimens that block B cell responses to AAV vectors or treatments that remove AAV neutralizing antibodies thus need to be developed to allow for a shift from toxic single-dose injections of AAV vectors to repeated treatments with more moderate and safe doses. Preventing or blocking antibody responses would also allow for redosing of patients with declining transgene product expression, or for effective AAV-mediated gene transfer into patients with the pre-existing neutralizing antibodies.

A new era in the science and care of kidney diseases

Notable progress in basic, translational and clinical nephrology research has been made over the past five decades. Nonetheless, many challenges remain, including obstacles to the early detection of kidney disease, disparities in access to care and variability in responses to existing and emerging therapies. Innovations in drug development, research technologies, tissue engineering and regenerative medicine have the potential to improve patient outcomes. Exciting prospects include the availability of new drugs to slow or halt the progression of chronic kidney disease, the development of bioartificial kidneys that mimic healthy kidney functions, and tissue engineering techniques that could enable transplantable kidneys to be created from the cells of the recipient, removing the risk of rejection. Cell and gene therapies have the potential to be applied for kidney tissue regeneration and repair. In addition, about 30% of kidney disease cases are monogenic and could potentially be treated using these genetic medicine approaches. Systemic diseases that involve the kidney, such as diabetes mellitus and hypertension, might also be amenable to these treatments. Continued investment, communication, collaboration and translation of innovations are crucial to realize their full potential. In addition, increasing sophistication in exploring large datasets, implementation science, and qualitative methodologies will improve the ability to deliver transformational kidney health strategies.

A Comprehensive Review of Monoclonal Antibodies in Modern Medicine: Tracing the Evolution of a Revolutionary Therapeutic Approach

Monoclonal antibodies (mAbs) have emerged as potent therapeutic agents, revolutionizing the landscape of modern medicine. This comprehensive review traces the evolution of mAbs from their inception to their current prominence, highlighting key milestones in their development and exploring their diverse therapeutic applications. Beginning with an overview of their molecular structure and mechanisms of action, we delve into the production and engineering of mAbs, including hybridoma technology and recombinant DNA techniques. Therapeutic applications across various medical disciplines, including cancer treatment, autoimmune diseases, and infectious diseases, are examined in detail, showcasing the significant clinical successes of mAbs. Furthermore, this review discusses the challenges and opportunities in manufacturing scalability, cost-effectiveness, and access to therapies. Looking ahead, the implications of mAbs in future research and clinical practice are explored, emphasizing the potential for next-generation mAbs, personalized medicine, and integration with emerging modalities such as immunotherapy and gene therapy. In conclusion, the evolution of monoclonal antibodies underscores their transformative impact on healthcare and their continued promise to advance the frontiers of medicine.

Emerging biologic frontiers for Sjogren's syndrome: Unveiling novel approaches with emphasis on extra glandular pathology

Primary Sjögren's Syndrome (pSS) is a complex autoimmune disorder characterized by exocrine gland dysfunction, leading to dry eyes and mouth. Despite growing interest in biologic therapies for pSS, FDA approval has proven challenging due to trial complications. This review addresses the absence of a molecular-target-based approach to biologic therapy development and highlights novel research on drug targets and clinical trials. A literature search identified potential pSS treatment targets and recent advances in molecular understanding. Overlooking extraglandular symptoms like fatigue and depression is a notable gap in trials. Emerging biologic agents targeting cytokines, signal pathways, and immune responses have proven efficacy. These novel therapies could complement existing methods for symptom alleviation. Improved grading systems accounting for extraglandular symptoms are needed. The future of pSS treatment may involve gene, stem-cell, and tissue-engineering therapies. This narrative review offers insights into advancing pSS management through innovative biologic interventions.

B cells and the stressed brain: emerging evidence of neuroimmune interactions in the context of psychosocial stress and major depression

The immune system has emerged as a key regulator of central nervous system (CNS) function in health and in disease. Importantly, improved understanding of immune contributions to mood disorders has provided novel opportunities for the treatment of debilitating stress-related mental health conditions such as major depressive disorder (MDD). Yet, the impact to, and involvement of, B lymphocytes in the response to stress is not well-understood, leaving a fundamental gap in our knowledge underlying the immune theory of depression. Several emerging clinical and preclinical findings highlight pronounced consequences for B cells in stress and MDD and may indicate key roles for B cells in modulating mood. This review will describe the clinical and foundational observations implicating B cell-psychological stress interactions, discuss potential mechanisms by which B cells may impact brain function in the context of stress and mood disorders, describe research tools that support the investigation of their neurobiological impacts, and highlight remaining research questions. The goal here is for this discussion to illuminate both the scope and limitations of our current understanding regarding the role of B cells, stress, mood, and depression.

B-cell targeted therapies in autoimmune encephalitis: mechanisms, clinical applications, and therapeutic potential

Autoimmune encephalitis (AE) broadly refers to inflammation of the brain parenchyma mediated by autoimmune mechanisms. In most patients with AE, autoantibodies against neuronal cell surface antigens are produced by B-cells and induce neuronal dysfunction through various mechanisms, ultimately leading to disease progression. In recent years, B-cell targeted therapies, including monoclonal antibody (mAb) therapy and chimeric antigen receptor T-cell (CAR-T) therapy, have been widely used in autoimmune diseases. These therapies decrease autoantibody levels in patients and have shown favorable results. This review summarizes the mechanisms underlying these two B-cell targeted therapies and discusses their clinical applications and therapeutic potential in AE. Our research provides clinicians with more treatment options for AE patients whose conventional treatments are not effective.

CD19-targeting CAR T cells protect from ANCA-induced acute kidney injury

OBJECTIVES

Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides (AAV) are life-threatening systemic autoimmune diseases manifesting in the kidneys as necrotizing crescentic glomerulonephritis (NCGN). ANCA antigens are myeloperoxidase (MPO) or proteinase 3. Current treatments include steroids, cytotoxic drugs and B cell-depleting antibodies. The use of chimeric antigen receptor (CAR) T cells in autoimmune diseases is a promising new therapeutic approach. We tested the hypothesis that CAR T cells targeting CD19 deplete B cells, including MPO-ANCA-producing B cells, thereby protecting from ANCA-induced NCGN.

METHODS

We tested this hypothesis in a preclinical MPO-AAV mouse model. NCGN was established by immunisation of MPO-/- mice with murine MPO, followed by irradiation and transplantation with haematopoietic cells from wild-type mice alone or together with either CD19-targeting CAR T cells or control CAR T cells.

RESULTS

CD19 CAR T cells efficiently migrated to and persisted in bone marrow, spleen, peripheral blood and kidneys for up to 8 weeks. CD19 CAR T cells, but not control CAR T cells, depleted B cells and plasmablasts, enhanced the MPO-ANCA decline, and most importantly protected from NCGN.

CONCLUSION

Our proof-of-principle study may encourage further exploration of CAR T cells as a treatment for ANCA-vasculitis patients with the goal of drug-free remission.

Breg-Mediated Immunoregulation in the Skin

Wound healing is a complex process involving a coordinated series of events aimed at restoring tissue integrity and function. Regulatory B cells (Bregs) are a subset of B lymphocytes that play an essential role in fine-tuning immune responses and maintaining immune homeostasis. Recent studies have suggested that Bregs are important players in cutaneous immunity. This review summarizes the current understanding of the role of Bregs in skin immunity in health and pathology, such as diabetes, psoriasis, systemic sclerosis, cutaneous lupus erythematosus, cutaneous hypersensitivity, pemphigus, and dermatomyositis. We discuss the mechanisms by which Bregs maintain tissue homeostasis in the wound microenvironment through the promotion of angiogenesis, suppression of effector cells, and induction of regulatory immune cells. We also mention the potential clinical applications of Bregs in promoting wound healing, such as the use of adoptive Breg transfer.

Daratumumab for autoimmune diseases: a systematic review

OBJECTIVE

Refractory autoimmune diseases remain a significant challenge in clinical practice and new therapeutic options are needed. This systematic review evaluates the existing reported data on the CD38-targeting antibody daratumumab as a new therapeutic approach in autoantibody-mediated autoimmune diseases.

METHODS

A protocolised systematic literature review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. Two databases (Medline and Embase) were searched for suitable studies. Usage of daratumumab in non-oncological or non-transplantation associated diseases with autoimmune pathophysiology was analysed including patient characteristics, therapeutic regimen, adverse events and patient outcome.

RESULTS

38 publications reporting the clinical course of 83 patients met the inclusion criteria. Daratumumab usage was reported in therapy-refractory cases (median of 5 different previous therapies) in 24 different autoimmune diseases. The median number of applications of daratumumab was 4, mainly via intravenous applications (87%). Concomitant treatment included glucocorticoids in 64% of patients, intravenous immunoglobulins (33%) and rituximab (17%). Remission or improvement of disease was reported in 81% of patients. Autoantibody depletion or reduction was stated in 52% of patients. Death occurred in three patients (3%). Adverse events were reported in 45% of patients including application-associated reaction (20%), infection (19%) and hypogammaglobulinaemia (33%).

CONCLUSION

Targeting CD38 via daratumumab is a new promising therapeutic option in therapy refractory autoimmune diseases. Efficacy as well as optimal therapeutic regimen and management or prevention of adverse events require further investigation. Therefore, systematic clinical trials of this therapeutic approach are needed.

Elucidating the neuroimmunology of traumatic brain injury: methodological approaches to unravel intercellular communication and function

The neuroimmunology of traumatic brain injury (TBI) has recently gained recognition as a crucial element in the secondary pathophysiological consequences that occur following neurotrauma. Both immune cells residing within the central nervous system (CNS) and those migrating from the periphery play significant roles in the development of secondary brain injury. However, the precise mechanisms governing communication between innate and adaptive immune cells remain incompletely understood, partly due to a limited utilization of relevant experimental models and techniques. Therefore, in this discussion, we outline current methodologies that can aid in the exploration of TBI neuroimmunology, with a particular emphasis on the interactions between resident neuroglial cells and recruited lymphocytes. These techniques encompass adoptive cell transfer, intra-CNS injection(s), selective cellular depletion, genetic manipulation, molecular neuroimaging, as well as in vitro co-culture systems and the utilization of organoid models. By incorporating key elements of both innate and adaptive immunity, these methods facilitate the examination of clinically relevant interactions. In addition to these preclinical approaches, we also detail an emerging avenue of research that seeks to leverage human biofluids. This approach enables the investigation of how resident and infiltrating immune cells modulate neuroglial responses after TBI. Considering the growing significance of neuroinflammation in TBI, the introduction and application of advanced methodologies will be pivotal in advancing translational research in this field.