cell therapies

2026-08-16 | FOXP3 as a therapeutic target in autoimmune diseases: Molecular regulation, regulatory T cells, and emerging precision immunotherapies

Forkhead box protein P3 (FOXP3) is a key transcription factor responsible for the development and function of regulatory T cells (Tregs), which play a crucial role in maintaining immune tolerance and preventing autoimmune responses. Defects in FOXP3 expression or function can impair Treg activity, leading to immune dysregulation and the development of autoimmune diseases. While complete loss of FOXP3 results in immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, altered FOXP3 expression and Treg dysfunction have also been reported in common autoimmune disorders such as systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes mellitus, multiple sclerosis, and inflammatory bowel disease. Recent advances have significantly improved our understanding of the molecular mechanisms regulating FOXP3, including transcriptional control, epigenetic modifications, metabolic pathways, and environmental influences that affect Treg stability and function. These discoveries have led to the development of novel therapeutic approaches aimed at restoring immune tolerance through enhancement of FOXP3 activity and Treg-mediated suppression. Strategies such as low-dose interleukin-2 therapy, adoptive Treg cell transfer, antigen-specific Treg therapy, chimeric antigen receptor regulatory T cells (CAR-Tregs), and gene-editing technologies have shown promising results in preclinical and early clinical studies. This review summarizes the current understanding of FOXP3 biology, its role in autoimmune disease pathogenesis, and recent advances in FOXP3-directed therapeutic strategies. In addition, emerging concepts including Treg plasticity, epigenetic regulation, immunometabolism, and precision immunotherapy are discussed. A better understanding of FOXP3-mediated immune regulation may facilitate the development of targeted therapies capable of achieving long-term immune tolerance and improved clinical outcomes in patients with autoimmune diseases.

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2026-07-28 | Limosilactobacillus reuteri-educated T cells protect against activation of liver inflammation in immunocompromised mice 2229185

Abstract Introduction Oral administration of probiotic Limosilactobacillus reuteri DSM 17938 prolongs survival and reduces Th1- and Th2-associated inflammation in Treg-deficient scurfy (SF) mice, which model human IPEX syndrome. It is unclear how DSM 17938 educated SF-CD4+T cells can facilitate T cell-liver communication. Methods We adoptively transferred by intraperitoneal injection cells isolated from SF spleens into lymphocyte-deficient-RAG1KO mice and compared the CD4+T cells from SF mice gavage-fed with DSM 17938 with the CD4+T cells from untreated SF mice (Prob-SF-CD4+T cells versus SF-CD4+T cells). Liver inflammatory histology and transcriptomes in RAG1KO mice were analyzed. Results We observed that Prob-SF-CD4+T cells reduced the incidence and severity of liver inflammation caused by transferring SF-CD4+T cells. SF-CD4+T cells up-regulated expression of liver genes involved in TLR cascades, inflammatory cytokine and death receptor signals, while down-regulated genes linked to mitochondrial respiratory chain complexes, TCA cycle, liver detoxification and lipid metabolism. However, Prob-SF-CD4+T cell transfer reversed SF-CD4+T cell-induced transcriptomic changes in inflammatory and metabolic clusters by modulating distinct genes participating in TLR regulation, mitochondrial function and cell cycle. Conclusion In conclusion, inflammatory CD4+T cells can perpetuate an exaggerated immune response in the immunologically naïve host. DSM17938 has the capacity to reprogram inflammatory CD4+T cells and allowed them to benefit the recipient. Probiotic-modulated T cells can be further explored as a therapeutic option for autoimmune liver diseases. Funding Source National Institutes of Health (NIH)/National Institute of Allergy and Infectious Diseases (NIAID) R03AI153725 Topic Categories Therapeutic Approaches to Autoimmunity (THER)

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2026-06-26 | FOXP3 Mutations and Instability as Determinants of Regulatory T-Cell Plasticity in Endocrine Autoimmunity

Autoimmune endocrine diseases constitute a group of disorders characterized by immune-mediated destruction or dysfunction of hormone-producing glands. The pathogenesis of these diseases reflects a breakdown of immune tolerance in which regulatory T cells (Tregs) play a key role. The transcription factor forkhead box P3 (FOXP3) is a master regulator of Treg differentiation and suppressive function. Also, it is central to maintaining self-tolerance. Genetic mutations in FOXP3, including those responsible for immune dysregulation, polyendocrinopathy, enteropathy X-linked (IPEX) syndrome, highlight the critical role of FOXP3 in endocrine immune tolerance. Emerging evidence suggests that autoimmune endocrine disorders may reflect organ-specific destabilization of FOXP3 expression rather than complete Treg deficiency. The reversibility or irreversible loss of FOXP3 gene expression represents a key determinant of Treg plasticity and the persistence of autoimmune inflammation. This review proposes an integrated genetic–epigenetic model of FOXP3 instability and examines how the endocrine microenvironment shapes Treg plasticity. Genetic or epigenetic alterations affecting FOXP3 expression can impair Treg activity and precipitate endocrine organ-specific autoimmunity. Epigenetic mechanisms such as DNA methylation, histone modifications, and non-coding RNA-mediated regulation that modulate FOXP3 transcriptional activity are discussed. From a translational perspective, the potential of FOXP3 as a biomarker for endocrine disease susceptibility and progression was summarized. Furthermore, therapeutic strategies employed for expanding or engineering functional FOXP3+ Tregs using antigen-specific vaccines, chimeric antigen receptors (CAR)-Tregs, gene therapy, or low-dose interleukin-2 (IL-2) were described.

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2026-03-19 | Limosilactobacillus reuteri alleviates proinflammatory T-cell-mediated liver injury and transcriptomic changes in immunocompromised mice.

A deficiency of immunosuppressive regulatory T cells, as seen in scurfy (SF) mice or in IPEX syndrome in humans, can lead to multiorgan inflammation. Oral administration of the probiotic Limosilactobacillus reuteri Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSM) 17938 prolongs survival and reduces Th1- and Th2-associated inflammation in SF mice. It remains unclear how DSM 17938-educated SF-CD4+ T cells modulate T-cell-liver communication. To characterize CD4+ T cells from SF mice orally administered DSM 17938 (Prob-SF-CD4+ T cells) and to compare them with CD4+ T cells from SF mice (SF-CD4+ T cells), cells isolated from SF spleens were adoptively transferred by intraperitoneal (IP) injection into lymphocyte-deficient Recombination-Activating Gene (RAG)-1-deficient (RAG1KO) mice. Liver histological inflammation and macrophages (MΦs), liver sample transcriptomes by RNAseq, and stool microbiota by 16S rRNA sequencing were then assessed in RAG1KO mice. Prob-SF-CD4+ T cells reduced the incidence and severity of liver inflammation and F4/80+MΦ infiltration by SF-CD4+ T-cell transfer. SF-CD4+ T cells upregulated genes and altered RNA splicing factors and events involved in inflammatory pathways, including Toll-like receptor (TLR) cascades, inflammatory cytokines, and death receptor signals. SF-CD4+ T cells downregulated genes linked to metabolism, including mitochondrial function, the TCA cycle, lipids, and liver detoxification. Prob-CD4+ T-cell transfer reversed SF-CD4+ T-cell-induced gene changes in inflammatory and metabolic interactive clusters while modulating distinct genes involved in TLR regulation and the cell cycle. CD4+ T-cell transfer altered gut microbial diversity compared with RAG1KO mice without CD4+ T-cell transfer. Prob-SF-CD4+ T-cell transfer exclusively increased the relative abundance (RA) of Incertae_sedis and reduced the RA of Clostridia_vadinBB60_group in the stool of RAG1KO mice. Inflammatory lymphocytes (CD4+ T cells) can perpetuate an exaggerated immune response in an immunologically naïve host. Feeding with DSM 17938 modulated T cells and allowed them to provide beneficial effects to the recipient. We observed activation of multiple genes and their interactions. These findings suggest that probiotics or probiotic-modulated T cells could be further explored as therapeutic options for autoimmune liver diseases.

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2026-03-15 | Preclinical efficacy and safety assessment of engineered regulatory T cells for treatment of IPEX and other autoimmune disorders.

FOXP3 is an essential transcription factor driving lineage commitment and function of regulatory T cells (Tregs). We previously reported a proof-of-concept study describing engineered Tregs (EngTregs) generated using homology-directed repair-based editing of the FOXP3 gene in CD4+ T cells, resulting in constitutive, high-level endogenous FOXP3 expression leading to acquisition of a Treg phenotype and robust in vitro and in vivo suppressive function. Here, we expand this gene-editing strategy to integrate a functional FOXP3 cDNA to enable EngTreg therapy for immune dysregulation, poly-endocrinopathy, enteropathy, X-linked syndrome (IPEX), a devastating multiorgan autoimmune disorder mediated by mutations within the FOXP3 gene. We provide a detailed characterization of preclinical EngTreg generation, including gene targeting efficiencies, cell enrichment and expansion, analyses of potential off-target editing, and phenotypic and functional characterization, including in vitro suppression of effector T cells and in vivo reversal of graft-versus-host disease. Importantly, in parallel, we utilize syngeneic and humanized mouse models to demonstrate the safety of EngTregs in primary and secondary humoral responses and viral infection control, respectively. Our combined preclinical dataset strongly supports the efficacy and safety of EngTregs as a promising potential cellular therapeutic approach for IPEX and possibly other autoimmune disorders.

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proteins

2026-05-01 | Peripheral Expression of FOXP3 in Brazilian Patients with IPEX Syndrome: From FOXP3 Biomarker to Targeted FOXP3 Therapy Within the CNE3I

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a monogenic disorder caused by loss-of-function mutations in the FOXP3 gene, which is critical for the development of functional regulatory T cells (Tregs). In IPEX patients, Tregs are unable to inhibit effector T cell proliferation and cytokine production, leading to a loss of peripheral immune tolerance. The disease presents with heterogeneous clinical manifestations, severe early-onset autoimmunity, the classic triad (enteropathy, eczema, and type 1 diabetes), as well as atypical or late-onset symptoms. A clear genotype–phenotype correlation has not been established for IPEX, and immunological assessments that could contribute to the diagnosis are scarce. Therefore, we aim to characterize the peripheral Treg cells in IPEX patients in Brazil through combined quantitative and qualitative flow cytometry analysis. We enrolled 6 male patients with a confirmed IPEX diagnosis (clinical, genetic, and immunological). All patients exhibited autoimmunity (enteropathy: 5/6; arthritis: 3/6; hemolytic anemia: 2/6; type 1 diabetes: 2/6), and allergic manifestations (rhinitis: 6/6; asthma: 4/6), eczema (4/6), and recurrent sinusitis (4/6) were also observed. Up to the last follow-up, two patients were alive after bone marrow transplantation and one after gene therapy (Figure 1). Peripheral FOXP3 expression was assessed in peripheral blood mononuclear cells (PBMCs) by flow cytometry (CD3, CD4, CD25, CD127, and FOXP3). Quantitative analysis determined the frequency of Tregs (CD4+CD25+CD127-FOXP3+), while qualitative analysis measured FOXP3 protein expression via median fluorescence intensity (MFI). The frequency of circulating Tregs in IPEX patients from our cohort was highly variable (14.6%–81.2%; mean: 58.5%) and overlapped with the control range (59.6%–84.1%; mean: 72.4%). In contrast, FOXP3 MFI was significantly lower in patient Tregs (mean: 986, range: 863–1,276) compared to controls (mean: 1,937, range: 1,089–4,132; p<0.05), another indication of quantitative Treg defects. Different patterns of FOXP3 expression have been reported, depending on the type and location of the mutation. While Treg numbers can be preserved in IPEX syndrome, FOXP3 protein expression per cell is consistently and significantly reduced. This defect in the expression level of FOXP3 likely underlies Treg dysfunction and disease pathogenesis. Assessment of FOXP3 MFI emerges as an additional valuable complementary diagnostic tool, providing functional insight beyond genetic sequencing alone. Figure 1. Clinical, immunologic, genetic, and therapeutic findings for IPEX syndrome within the CNE3i (Centro Nacional de Erros Inatos da Imunidade e Imunodesregulação) in Brazil. (1) Demonstrates the main clinical and geographical findings of the six IPEX patients; (2) general and advanced laboratory findings; and (3) genetics and therapeutics. SP, São Paulo; MG, Minas Gerais; PE, Pernambuco; DF, Distrito Federal; ES, Espírito Santo; IgE, immunoglobulin E; IgG immunoglobulin G; DNT, double negative T cells; IFN-SG, interferon-stimulated genes; MFI, median fluorescence intensity; BMT, bone marrow transplantation; GT, gene therapy; LFW, last follow-up. FINEP funding: 0956/24; FAPESP funding: 2023/09965-0; Instituto de Investigação em Imunologia funding CNPQ/MCTI: 408685/2024-7.

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2025-11-01 | Foxp3 M370I mutation allows the activation of T effector programs in regulatory T cells 3759

Abstract Description The transcription factor Foxp3 in mice dictates the development and function of regulatory T cells (Tregs) to maintain self-tolerance. The mutation of amino acid 370 (M to I) of FOXP3 protein was identified in IPEX patients with type-2 autoimmunity. We generated an M370I-knock in (KI) mouse by CRISPR-Cas9. The homozygous female KI (Foxp3M370I/M370I) mice and the hemizygous male KI (Foxp3M370I/Y) mice showed T cell activation with multi-organ inflammation. The KI Tregs were capable to produce effector T cell cytokines (IL-2, IFN-γ, IL-4, and IL-17A). We also generated heterozygous KI female (Foxp3M370I/GFP) mice which were healthy in general without type-2 inflammation. However, the KI Tregs still possessed the ability of producing IL-2/IFN-γ. IP-MS of Foxp3 showed an altered pattern of Foxp3 interacting proteins between WT and KI Tregs, including NFAT and RUNX1. Structural modelling indicated that M370I may disrupt head-to-head dimerization of FOXP3. While another amino acid substitution F374C that sits in the center of H4 helix, may form an intra-domain disulfide to favor swap-domain dimer. We further generated mice carrying FOXP3-F374C mutation and these mice indeed had similar phenotypes. Thus, our results indicate that M370I and F374C KI Tregs displayed effector-phenotypes, possibly resulting from enhanced formation of domain-swap FOXP3 dimerization. This work was supported by the Division of Intramural Research of NIAID, NIH. Funding Sources NIH/NIAID 1ZIAAI001169 Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)

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2025-09-04 | Case report: anti-IL-6 autoantibodies in a patient with immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome

We describe an atypical presentation of Immune dysregulation, Polyendocrinopathy, Enteropathy, X-linked syndrome. The patient exhibited food allergies and eczema, along with recurrent and severe infections, but notably lacked the hallmark chronic diarrhea and autoimmune polyendocrinopathy. Whole-exome sequencing revealed the hemizygous FOXP3 variant c.210+1G>T resulting in a loss of protein expression. Immunophenotyping showed an unusual overlap between immune deficiency and immune dysregulation. The patient had CD4 + lymphopenia, with a marked reduction of naïve CD4 + T cells, and impaired T cell proliferation to specific antigens. Moreover, he had reduced serum levels of immunoglobulin (Ig) G2, IgA, and IgM, but high IgE levels and eosinophilia. Given these features consistent with a cellular and humoral immune defect predisposing to infections, the patient was treated with immunoglobulin replacement therapy, which was beneficial. We identified an altered immunophenotypic signature shared between T regulatory and T effector cells. This T helper 1-like memory phenotype corresponded to an increased secretion of interferon-γ following ex vivo stimulation of peripheral mononuclear cells. A key immunological finding was the presence of likely neutralizing anti-IL-6 autoantibodies which, to the best of our knowledge, have never been reported in patients with IPEX syndrome. Although documented later in the disease course, the latter might explain the Hyper IgE syndrome-like features displayed by the patient, including the allergic manifestations in the absence of hyperactivation of the T helper 2 compartment, as well as the poor inflammatory response during infections. This case extends our knowledge of IPEX syndrome by: i) expanding the spectrum of clinical presentations; ii) revealing a distinct phenotypic signature affecting both T regulatory and T effector cells; iii) suggesting that autoantibodies against cytokines may play a previously underappreciated role in shaping the disease manifestations, not only by driving immune dysregulation and allergy but also by impairing immune defense against infections.

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2025-09-04 | Image 2_Case report: anti-IL-6 autoantibodies in a patient with immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome.jpeg

We describe an atypical presentation of Immune dysregulation, Polyendocrinopathy, Enteropathy, X-linked syndrome. The patient exhibited food allergies and eczema, along with recurrent and severe infections, but notably lacked the hallmark chronic diarrhea and autoimmune polyendocrinopathy. Whole-exome sequencing revealed the hemizygous FOXP3 variant c.210+1G>T resulting in a loss of protein expression. Immunophenotyping showed an unusual overlap between immune deficiency and immune dysregulation. The patient had CD4+ lymphopenia, with a marked reduction of naïve CD4+ T cells, and impaired T cell proliferation to specific antigens. Moreover, he had reduced serum levels of immunoglobulin (Ig) G2, IgA, and IgM, but high IgE levels and eosinophilia. Given these features consistent with a cellular and humoral immune defect predisposing to infections, the patient was treated with immunoglobulin replacement therapy, which was beneficial. We identified an altered immunophenotypic signature shared between T regulatory and T effector cells. This T helper 1-like memory phenotype corresponded to an increased secretion of interferon-γ following ex vivo stimulation of peripheral mononuclear cells. A key immunological finding was the presence of likely neutralizing anti-IL-6 autoantibodies which, to the best of our knowledge, have never been reported in patients with IPEX syndrome. Although documented later in the disease course, the latter might explain the Hyper IgE syndrome-like features displayed by the patient, including the allergic manifestations in the absence of hyperactivation of the T helper 2 compartment, as well as the poor inflammatory response during infections. This case extends our knowledge of IPEX syndrome by: i) expanding the spectrum of clinical presentations; ii) revealing a distinct phenotypic signature affecting both T regulatory and T effector cells; iii) suggesting that autoantibodies against cytokines may play a previously underappreciated role in shaping the disease manifestations, not only by driving immune dysregulation and allergy but also by impairing immune defense against infections.

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2024-03-20 | Immune tolerance and the prevention of autoimmune diseases essentially depend on thymic tissue homeostasis

The intricate balance of immune reactions towards invading pathogens and immune tolerance towards self is pivotal in preventing autoimmune diseases, with the thymus playing a central role in establishing and maintaining this equilibrium. The induction of central immune tolerance in the thymus involves the elimination of self-reactive T cells, a mechanism essential for averting autoimmunity. Disruption of the thymic T cell selection mechanisms can lead to the development of autoimmune diseases. In the dynamic microenvironment of the thymus, T cell migration and interactions with thymic stromal cells are critical for the selection processes that ensure self-tolerance. Thymic epithelial cells are particularly significant in this context, presenting self-antigens and inducing the negative selection of autoreactive T cells. Further, the synergistic roles of thymic fibroblasts, B cells, and dendritic cells in antigen presentation, selection and the development of regulatory T cells are pivotal in maintaining immune responses tightly regulated. This review article collates these insights, offering a comprehensive examination of the multifaceted role of thymic tissue homeostasis in the establishment of immune tolerance and its implications in the prevention of autoimmune diseases. Additionally, the developmental pathways of the thymus are explored, highlighting how genetic aberrations can disrupt thymic architecture and function, leading to autoimmune conditions. The impact of infections on immune tolerance is another critical area, with pathogens potentially triggering autoimmunity by altering thymic homeostasis. Overall, this review underscores the integral role of thymic tissue homeostasis in the prevention of autoimmune diseases, discussing insights into potential therapeutic strategies and examining putative avenues for future research on developing thymic-based therapies in treating and preventing autoimmune conditions.

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small molecules

2026-09-04 | Targeting the FOXP3-T-bet interaction to restore Treg stability in IFN-γ-driven autoimmunity.

Regulatory T-cell (Treg) stability is maintained by dynamic remodeling of the FOXP3 transcriptional complex, and disruption of this complex leads to Treg dysfunction and immune dysregulation. However, how specific FOXP3 mutations alter the dynamic remodeling of the FOXP3 complex and thereby contribute to pathogenic Treg reprogramming in IPEX syndrome remains unclear. Here, we demonstrate that predominant Th1 inflammation manifests in both FOXP3V408M IPEX patients and FOXP3V408M knock-in mice and reveal that the mutation intrinsically impairs Treg-mediated control of Th1 inflammation, revealing a distinct pathogenesis of this mutation in IPEX syndrome. Mechanistically, the V408M mutation disrupts the FOXP3-T-bet interaction, impairing the FOXP3-mediated restraint of T-bet-driven IFN-γ production and thereby contributing to increased Th1 inflammation. Using an AI-driven virtual screening approach, we identified a first-in-class small molecule, FM029, that directly binds to FOXP3 and reinforces its interaction with T-bet. FM029 strongly suppressed Treg-derived IFN-γ production and alleviated IFN-γ-driven tissue inflammation in both FOXP3V408M mice and an acute colitis model. Collectively, these findings establish the FOXP3-T-bet interaction as a central checkpoint that governs Treg stability and IFN-γ-driven Th1 pathology, providing a proof-of-concept that pharmacologic stabilization of the FOXP3-T-bet interaction can mitigate IFN-γ-driven immune disorders.

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2026-09-03 | Unraveling primary immune regulatory disorders: A comprehensive narrative review from clinical suspicion to diagnosis and management

Historically defined by infectious susceptibility, Primary Immunodeficiencies (PIDs) have evolved into Inborn Errors of Immunity (IEI), including Primary Immune Regulatory Disorders (PIRDs), where immune dysregulation predominates. Despite genetic advances, a 70% "diagnostic gap" persists. This review provides a framework for PIRD management through phenotypic selection, deep sequencing for mosaicism, and multi-omics integration. Phenotypic stringency, such as that applied to fulfill ALPS or IPEX-like criteria, can improve diagnostic yield. Technologies like long-read genome sequencing (lrGS) and targeted amplicon-based deep sequencing (ADS) are essential for resolving structural variants and low frequency variant allele fraction (VAF) somatic events (VAF < 5%) missed by standard pipelines. Furthermore, precision therapies, including JAK inhibitors, Leniolisib, and Abatacept, seems promissing therapeutic approaches to restore immunological homeostasis. Closing the diagnostic gap requires a multimodal approach integrating clinical expertise, advanced genomics, and functional translation. Ultimately, precision immunology is shifting IEI management toward targeted control and potential cure via gene editing.

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2026-07-28 | Targeting the FOXP3—T-bet interaction to restore Treg stability in IFN-γ—driven autoimmunity 2254306

Abstract Introduction Regulatory T cells (Tregs) maintain immune homeostasis through FOXP3-centered transcriptional complexes that tightly control lineage stability and suppressive function. However, how specific FOXP3 mutations disturb this complex and drive pathogenic Treg reprogramming in IPEX syndrome remains unclear. We identified a distinctive mechanism by which the FOXP3 V408M mutation promotes Th1-skewed inflammation and also explored a pharmacological strategy to restore Treg stability. Methods We generated FOXP3 V408M knock-in mice and performed immunophenotyping, transcriptomic, and chromatin conformation analyses to determine how the mutation affects FOXP3—T-bet interaction and Ifng transcription. An AI-driven virtual screening strategy integrating sequence- and structure-based modeling was applied to identify compounds that stabilize FOXP3—T-bet interaction. Functional validation was performed in vitro and in multiple in vivo mouse models. Results FOXP3 V408M mutation disrupted the FOXP3—T-bet interaction, thereby releasing T-bet from FOXP3-mediated repression and enhancing Ifng transcription. This defect reprogrammed Tregs toward an IFN-γ—producing phenotype that promoted Th1 inflammation. Among the AI-driven screening hits, 430C10 emerged as a first-in-class FOXP3-targeting stabilizer binding an allosteric pocket within the FKH domain. 430C10 reinforced the FOXP3—T-bet interaction and suppressed T-bet—driven IFN-γ production by Tregs. Oral 430C10 treatment markedly alleviated IFN-γ+ Treg—driven inflammation in FOXP3 V408M mice and improved disease outcomes in an acute colitis model under FOXP3 WT settings. Conclusion Our findings define the FOXP3—T-bet interaction as a tunable checkpoint controlling Treg stability and IFN-γ—driven autoimmunity. Pharmacological stabilization of this interaction with 430C10 provides a proof-of-concept therapeutic strategy for restoring immune homeostasis in IPEX syndrome and related autoimmune diseases. Funding Source Our research is supported by National Natural Science Foundation of China (82271829, 32130041, 82441047, 82241222); The Innovation Program of Shanghai Municipal Education Commission (21140902900); Noncommunicable Chronic Diseases-National Science and Tech Topic Categories Therapeutic Approaches to Autoimmunity (THER)

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2026-02-02 | Metadichol Orchestrates Cellular Reprogramming and Regenerative Pathways via FOX Transcription Factor Networks: Implications for Immune–Metabolic Rejuvenation

Significance: The 2025 Nobel Prize in Physiology or Medicine was awarded to Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi for their groundbreaking discoveries concerning peripheral immune tolerance, specifically identifying the FOXP3 gene as the master regulator of regulatory T cells (Tregs). Their work demonstrated that FOXP3 mutations cause severe autoimmune disease (IPEX syndrome), establishing FOXP3 as essential for immune self-tolerance. This study demonstrates that Metadichol significantly upregulates FOXP3 expression (5.46-fold), providing a novel pharmacological approach to enhance regulatory T-cell function and immune homeostasis—directly relevant to the Nobel Prize-winning discoveries. Background: Forkhead box (FOX) transcription factors constitute a large family of regulatory proteins that control diverse cellular processes, including development, metabolism, immunity, and aging. Metadichol, a nano lipid formulation derived from long-chain alcohols, has demonstrated pleiotropic biological effects, including immunomodulation and metabolic regulation. Objective: To comprehensively evaluate the effects of metadichol treatment on FOX transcription factor gene expression in human peripheral blood mononuclear cells (PBMCs) via quantitative PCR analysis. Methods: Human PBMCs were isolated via Histopaque density gradient centrifugation and treated with Metadichol at concentrations of 1 pg/ml, 100 pg/ml, 1 ng/ml, and 100 ng/ml. Total RNA was extracted, reverse- transcribed, and analyzed by quantitative PCR for 45 FOX genes. Gene expression changes were calculated via normalization to GAPDH via the 2^-ΔΔCq method. Results: Metadichol treatment resulted in dose-dependent modulation of FOX gene expression. At the highest concentration (100 ng/ml), significant upregulation of multiple FOX genes was observed, with FOXO1 showing the greatest increase (8.74-fold), followed by FOXA1 (7.39-fold) and FOXH1 (7.22-fold). Additional substantial increases were noted for FOXA2 (6.57-fold), FOXA3 (6.98-fold), FOXB1 (6.79-fold), FOXP3 (5.46-fold), and FOXP4 (6.23-fold). Conversely, selective downregulation was observed for FOXL2 (0.16-fold), FOXL1 (0.54- fold), and FOXD4L1 (0.56-fold). Conclusions: Metadichol has potent and selective effects on FOX transcription factor expression in human PBMCs, with preferential upregulation of genes involved in metabolic regulation, immune homeostasis, induced pluripotency and cellular longevity pathways. These findings suggest potential therapeutic applications in age- related diseases, metabolic disorders, and immunomodulation, and regenerative medicine. Importantly, the coordinated upregulation of pluripotency-associated genes, including FOXD3, FOXO1, and FOXM1, establishes Metadichol as a compelling modulator of cellular reprogramming networks with significant implications for advancing stem cell-based regenerative therapies. The differential expression patterns indicate complex regulatory mechanisms that warrant further investigation to elucidate their clinical translation potential. Key words: Fox family, Metadichol, immune metabolic rejuvenation, nuclear receptors, SOX family, Toll-like receptors, KLFs, sirtuins, circadian genes, GDF11, TERT, Klotho, induced pluripotency, regenerative medicine, 2025 Nobel Prize, FOXP3, regulatory T cells, immune tolerance.

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2025-11-26 | Overactive STAT3 Dysregulates BCR Signalling and Drives Accumulation and Autoreactivity of Disease-Associated CD21low B Cells

Introduction Signal transducer and activator of transcription 3 (STAT3) regulates gene expression downstream of cytokine/hormone receptors. Germline heterozygous STAT3 gain-of-function mutations cause early-onset multi-organ autoimmune disease, including type-1 diabetes, autoimmune thyroid disease, rheumatoid arthritis, enteropathies, autoimmune cytopenias, and/or B memory lymphopenia, many pointing to B cell tolerance defects. In populations, JAK-STAT3 polymorphisms and STAT3 signalling cytokines are associated with increased risk of B cell-mediated autoimmune diseases, and the cytokines’ levels correlate with disease severity. Finally, STAT3 can be mutated to gain-of-function and is frequently constitutively active in B lymphomas. Despite this, B cell-intrinsic effects of overactive STAT3 remain unknown. Method and Results We address this in patients, and mice engineered to carry the most common pathogenic germline gain-of-function mutation, STAT3T716M, or STAT3G421R and STAT3K658N, also found in lymphomas/leukemias. Gain-of-function STAT3 causes aberrant accumulation of polyclonal CD21low B cells resembling those that accumulate with age, chronic infections, immunodeficiency, and autoimmune diseases. It causes accumulation of self-reactive SWHEL B cells recognising a blood cell surface autoantigen and, in humans, of VH4-34+ B cells recognising I/i self-antigen on blood cells. Using mouse and human BCR deep sequencing, flow cytometry, single-cell RNA, and chromatin immunoprecipitation sequencing, we show overactive STAT3 induces a surprising and striking dysregulation of BCR signalling molecules, many of which are direct pSTAT3 targets, and dysregulates BCR-induced Tbet and atypical differentiation. We use in vivo inhibition to test whether STAT3-mutant atypical B cells are specifically depleted by BCR-PI3K inhibition. In a first-in-kind analysis, we study additive effects of JAK-STAT3 and BCR polymorphisms on atypical B cell abundance and mRNA phenotypes in single-cell expression quantitative trait loci and RNA sequencing data from &gt;1,000 individuals. Conclusion Our findings reveal the landscape of genes and proteins dysregulated by overactive STAT3 in B cells and a novel mechanism explaining over-accumulation of autoantibody-enriched CD21low B cells in multiple diseases characterised by JAK-STAT polymorphisms and/or over-abundant IL-6/IL-21 cytokines.

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antibodies

2026-09-01 | Case Report: Effective IL-4/IL-13 axis suppression and resolution of severe atopic dermatitis by dupilumab monotherapy in a patient with IPEX syndrome.

The treatment of immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome has largely focused on immunosuppression with little impact on the atopic manifestations of the disease. Dupilumab therapy has been used successfully in primary atopic diseases and immune regulatory disorders to control type 2 inflammation. Indeed, it has been reported in two prior IPEX cases, but in combination with immunosuppressive agents. Here, we are the first to report the clinical and immunologic impact of dupilumab monotherapy in IPEX. A 4-year-old boy with a confirmed hemizygous Forkhead box protein 3 (FOXP3) missense variant (c.1150G>A; p.Ala384Thr) presented with severe, treatment-refractory atopic dermatitis beginning in the newborn period, failure to thrive, lymphadenopathy, food and environmental allergies, asthma, recurrent febrile neutropenia, and type 1 diabetes mellitus, with a peak IgE of 74,625 IU/mL. Following initiation of dupilumab monotherapy at age 2, the patient had a marked improvement in atopic dermatitis by Eczema Area and Severity Index (EASI) score, a rapid decline in serum IgE, improved growth, reduced respiratory hospitalizations, and a profoundly improved quality of life. Immunologically, dupilumab effectively suppressed IgE and plasma interleukin-4 (IL-4) and IL-13 to healthy control levels. In addition, C-C motif chemokine ligand 27 (CCL27), important for cutaneous T-cell trafficking, was detected at healthy control levels. Upstream alarmins, eosinophil mediators, T helper 1 (Th1) cytokines, and Treg-specific demethylated region (TSDR) demethylation remained elevated-indicating ongoing systemic immune dysregulation not fully addressed by dupilumab alone. This case demonstrates that dupilumab monotherapy can effectively suppress the IL-4/IL-13 axis and substantially improve atopic manifestations in IPEX, potentially by restoring skin-specific immune tolerance through rebalancing cutaneous T-cell trafficking. These findings support dupilumab as a targeted adjunctive therapy for the atopic features of IPEX and provide a rationale for the systematic study of dupilumab alone or in combination with other immunosuppression regimens.

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2026-02-07 | Pediatric IPEX-Associated Dermatitis Responds To Dupilumab: Evidence from Skin Transcriptomics and Immune Profiling.

Immunodysregulation, Polyendocrinopathy, Enteropathy, and X-linked (IPEX) syndrome is a rare autoimmune disorder caused by mutations in the FOXP3 gene. Patients with IPEX frequently present with severe dermatitis, diabetes, and enteropathy. This study explores the efficacy of Dupilumab (an anti-IL-4Rα monoclonal antibody) in treating persistent, severe dermatitis in an IPEX patient refractory to conventional treatments like sirolimus. We conducted a clinical case study of a 2-year-old IPEX patient with refractory dermatitis. Whole-exome sequencing (WES) confirmed the FOXP3 mutation. Skin biopsies were analyzed for inflammatory gene expression by RNA sequencing and immunohistochemistry to characterize inflammatory pathways. Immune cell phenotyping was performed using flow cytometry pre- and post-treatment in peripheral blood mononuclear cells (PBMCs). The patient was treated with Dupilumab alongside sirolimus and prednisone. Clinical improvements were evaluated using the Eczema Area and Severity Index (EASI) score. Immunohistochemistry revealed elevated IL-13 expression. RNA sequencing of skin samples revealed upregulation of both Th1- and Th2-related genes, suggesting a dual inflammatory phenotype in IPEX dermatitis. The patient exhibited significant clinical improvement after 8 months of sustained Dupilumab therapy, with the EASI decreasing from 24.8 to 0.4. Flow cytometry demonstrated a reduction in Th1 and Th2 cell subsets post-treatment, accompanied by an increase in Treg and Th3 cell populations as well as enhanced expression of immunosuppressive markers such as CTLA-4 and CD39. Dupilumab appears promising as a therapeutic option for managing refractory dermatitis in IPEX, particularly by attenuating Th1/Th2 inflammation and promoting regulatory responses mediated by Treg and Th3 cells.

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2025-12-22 | CARD8: An Emerging Genetic Cause of Autoinflammatory and CVID-Like Syndromes?

Introduction CARD8 encodes the caspase recruitment domain-containing protein 8, a negative regulator of the NLRP3 inflammasome and a modulator of innate immune signaling. Although not yet formally classified among inborn errors of immunity (IEIs), emerging evidence suggests a potential role of CARD8 variants in autoinflammatory syndromes and immune dysregulation. Case Presentations We describe three unrelated patients from different families with variable phenotypes involving autoinflammation and immune dysregulation. Patient 1: A 15-year-old female with an IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked)-like phenotype, including alopecia universalis, growth retardation, pubertal delay, and elevated serum IL-18 levels. A heterozygous frameshift variant in CARD8 (c.40delG, p.Glu14fs) was identified. Patient 2: A 3-year-old male presenting with neonatal lupus-like rash, severe atopic dermatitis, refractory autoimmune cytopenias, persistent hepatitis, and total villous atrophy on intestinal biopsy (Marsh 3b). A heterozygous frameshift variant (c.68dupG, p.Ser24fs) was detected. Patient 3: A 42-year-old female with adult-onset CVID (common variable immunodeficiency)-like phenotype, including recurrent pneumonia, chronic diarrhea, and persistent hypogammaglobulinemia requiring immunoglobulin replacement. A heterozygous missense variant (c.1093A&gt;C, p.Met365Leu) was identified. Discussion These cases illustrate the broad clinical spectrum associated with CARD8 variants, ranging from severe early-onset autoinflammatory disease to adult-onset humoral immunodeficiency. The presence of elevated IL-18 and multi-organ involvement supports dysregulated inflammasome activation as a key pathogenic mechanism. Importantly, heterozygous variants may result in incomplete penetrance and variable expressivity, complicating diagnosis and counseling. Conclusion CARD8 mutations should be considered in patients presenting with unexplained autoinflammation, immune dysregulation, or CVID-like phenotypes. Recognition of this spectrum may facilitate earlier diagnosis, appropriate therapeutic interventions targeting IL-1/IL-18 pathways, and genetic counseling for affected families.

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2025-11-26 | Primary Immunodeficiency and Enteropathy: A Diagnostic and Therapeutic Challenge

Introduction Inborn errors of immunity (IEIs) frequently present with gastrointestinal manifestations, yet enteropathy remains a poorly characterized complication with debilitating sequelae. Often misdiagnosed as atypical coeliac disease or inflammatory bowel disease (IBD), primary immunodeficiency (PID)-associated enteropathy (PID-E) lacks specific diagnostic endoscopic or histological criteria. This review explores distinctions between PID-E and classic gastrointestinal (GI) diseases and outlines our national initiative to develop a clinical database of affected patients. Method We conducted a comprehensive review of peer-reviewed articles, registries, and case series describing GI manifestations in PIDs, focusing on immune-mediated mechanisms, diagnostic features, and immunosuppressive treatments. Concurrently, we distributed an expression of interest Google Survey via the Clinical Immunogenomics Research Consortium of Australasia (CIRCA) to estimate case numbers nationally. Exclusion criteria included self-limited GI infections (&lt;8 weeks), IBD diagnosed before the age of 6, and GI disease related to chronic granulomatous disease (CGD), X-linked inhibitor of apoptosis protein (XIAP) deficiency, and immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome. Results PID-E is loosely defined as chronic diarrhoea with malabsorption and small bowel inflammation not meeting diagnostic criteria for classic GI diseases. Histology is variable and often non-specific, including villous atrophy, intraepithelial lymphocytosis, graft-versus-host disease-like changes, and IBD-like inflammation, but commonly a notable absence of plasma cells. Diagnosis requires integration of clinical, histological, and immunological data. Optimal treatment has not been defined; however, biologic agents, including anti-TNF-alpha agents, CTLA-4 inhibitors, and mTOR inhibitors, have shown benefit in case reports. Our national survey yielded 20 responses, identifying an estimated 100–150 cases across Australia to date, contributing to a growing database to inform future research and clinical guidelines. Conclusion PID-E is a distinct clinical entity that requires early recognition and tailored management approach through multidisciplinary collaboration. Our multi-centre data collection highlights the heterogeneity of presentations, complications, and treatment in Australian patients with PID-E. There is a need for consensus guidelines and a national database to drive future research and improve patient outcomes.

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2025-01-23 | Reduced autoimmunity associated with deletion of host CD73.

CD73 is ubiquitously expressed and regulates critical functions across multiple organ systems. The sequential actions of CD39 and CD73 accomplish the conversion of adenosine triphosphate to adenosine and shift the adenosine triphosphate-driven proinflammatory immune cell milieu toward an anti-inflammatory state. This immunological switch is a major mechanism by which regulatory T (Treg) cells control inflammation. Foxp3 engages in Treg development and function. Foxp3 mutations result in the scurfy (SF) mouse phenotype and a rapidly lethal lymphoproliferative syndrome. We generated double knockout (KO) mouse (CD73KOSF) by breeding heterozygous Foxp3sf/J females to CD73KO male mice to remove host CD73. We initially aimed to use these mice to identify a specific probiotic-CD73 effect, previously shown for Limosilactobacillus reuteri DSM 17938. We expected CD73 deletion to enhance the severity of autoimmunity in SF mice. However, we unexpectedly observed that KO of host CD73 in SF mice clinically reduced the severity of autoimmunity including reduced ear thickness, increased ear size, and less deformed ears, along with less dry and brittle skin. KO of CD73 in SF mice significantly reduced the numbers of CD4+ and CD8+T cells in spleen and blood. We identified that KO of CD73 in SF mice reduced the numbers of T cells in the thymus compared with those in SF mice, indicating that the milder clinical phenotype may be due to reduced central and peripheral lymphoproliferation. These new findings suggest targeting CD73 could improve T cell-mediated dermatitis, one of the most common symptoms in Treg deficiency-associated primary immune deficiencies.

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2025-03-03 | Forkhead Box Protein P3 in the Immune System

Regulatory T cells (Tregs) play a central role in immune regulation and tolerance. The transcription factor FOXP3 is a master regulator of Tregs in both humans and mice. Mutations in FOXP3 lead to the development of IPEX syndrome in humans and the scurfy phenotype in mice, both of which are characterized by fatal systemic autoimmunity. Additionally, Treg dysfunction and FOXP3 expression instability have been implicated in nongenetic autoimmune diseases, including graft-versus-host disease, inflammatory bowel disease, rheumatoid arthritis, and multiple sclerosis. Recent investigations have explored FOXP3 expression in allergic diseases, revealing Treg alterations in food allergies, asthma, and atopic dermatitis. This review examines the multifaceted roles of FOXP3 and Tregs in health and various pathological states, including autoimmune disorders, allergic diseases, and cancer. Additionally, this review focuses on the impact of recent technological advancements in facilitating Treg-mediated cell and gene therapy approaches, including CRISPR/Cas9-based gene editing. The critical function of FOXP3 in maintaining immune homeostasis and tolerance to both self-antigens and alloantigens is emphasized. Considering the potential involvement of Tregs in allergic diseases, pharmacological interventions and cell-based immunomodulatory strategies may offer promising avenues for developing novel therapeutic approaches in this field.

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2024-12-11 | Foxp3 in the Immune System

Regulatory T cells (Tregs) play a central role in immune regulation and tolerance. The transcription factor FOXP3 is a master regulator of Tregs in both humans and mice. Mutations in FOXP3 lead to the development of IPEX syndrome in humans and the scurfy phenotype in mice, both of which are characterized by fatal systemic autoimmunity. Additionally, Treg dysfunction and FOXP3 expression instability have been implicated in non-genetic autoimmune diseases, including graft-versus-host disease, inflammatory bowel disease, rheumatoid arthritis, and multiple sclerosis. Recent investigations have explored FOXP3 expression in allergic diseases, revealing Treg alterations in food allergies, asthma, and atopic dermatitis. This review examines the multifaceted roles of FOXP3 and Tregs in health and various pathological states including autoimmune disorders, allergic diseases, and cancer. Additionally, this review focuses on the impact of recent technological advancements in facilitating Treg-mediated cell and gene therapy approaches, including CRISPR/Cas9-based gene editing. The critical function of FOXP3 in maintaining immune homeostasis and tolerance to both self-antigens and alloantigens has been emphasized. Considering the potential involvement of Tregs in allergic diseases, pharmacological interventions and cell-based immunomodulatory strategies may offer promising avenues for developing novel therapeutic approaches in this field.

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2024-10-30 | Expanding the spectrum of IPEX: from new clinical findings to novel treatments.

This review aims to provide an overview of recent research findings regarding immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, focusing on clinical and immunological novelties, as well as emerging treatment strategies, based on the published literature of the last few years. While it is well known that IPEX can present with a wide range of atypical clinical manifestations, new and unique phenotypes continue to emerge, making it essential to maintain a high level of clinical suspicion both at the time of diagnosis and during follow-up. This unpredictability in clinical presentation is further compounded by the lack of a clear genotype-phenotype correlation. A valuable tool for monitoring comes from recent discoveries regarding the epigenetic signature of Tregs, which, by correlating with disease severity, could prove to be a useful biomarker for diagnosis and ongoing management. The use of biological agents is emerging as an alternative to traditional immunosuppression. Additionally, ongoing studies are exploring the feasibility of gene therapy through the introduction of the wild-type FOXP3 into peripheral CD4 + T cells. Further research is needed to fully understand the variable clinical presentations of IPEX and optimize tailored therapies, ensuring better management and outcomes for affected individuals.

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2024-08-19 | IL-27 Gene Therapy Ameliorates IPEX Syndrome Caused by Germline Mutation of Foxp3 Gene: A Major Role for Induction of IL-10.

Inactivating mutations of Foxp3, the master regulator of regulatory T cell development and function, lead to immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome in mice and humans. IPEX is a fatal autoimmune disease, with allogeneic stem cell transplant being the only available therapy. In this study, we report that a single dose of adeno-associated virus (AAV)-IL-27 to young mice with naturally occurring Foxp3 mutation (Scurfy mice) substantially ameliorates clinical symptoms, including growth retardation and early fatality. Correspondingly, AAV-IL-27 gene therapy significantly prevented naive T cell activation, as manifested by downregulation of CD62L and upregulation of CD44, and immunopathology typical of IPEX. Because IL-27 is known to induce IL-10, a key effector molecule of regulatory T cells, we evaluated the contribution of IL-10 induction by crossing IL-10-null allele to Scurfy mice. Although IL-10 deficiency does not affect the survival of Scurfy mice, it largely abrogated the therapeutic effect of AAV-IL-27. Our study revealed a major role for IL-10 in AAV-IL-27 gene therapy and demonstrated that IPEX is amenable to gene therapy.

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2024-01-29 | Efficient and sustained FOXP3 locus editing in hematopoietic stem cells as a therapeutic approach for IPEX syndrome.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a monogenic disorder caused by mutations in the FOXP3 gene, required for generation of regulatory T (Treg) cells. Loss of Treg cells leads to immune dysregulation characterized by multi-organ autoimmunity and early mortality. Hematopoietic stem cell (HSC) transplantation can be curative, but success is limited by autoimmune complications, donor availability and/or graft-vs.-host disease. Correction of FOXP3 in autologous HSC utilizing a homology-directed repair (HDR)-based platform may provide a safer alternative therapy. Here, we demonstrate efficient editing of FOXP3 utilizing co-delivery of Cas9 ribonucleoprotein complexes and adeno-associated viral vectors to achieve HDR rates of >40% in vitro using mobilized CD34+ cells from multiple donors. Using this approach to deliver either a GFP or a FOXP3 cDNA donor cassette, we demonstrate sustained bone marrow engraftment of approximately 10% of HDR-edited cells in immune-deficient recipient mice at 16 weeks post-transplant. Further, we show targeted integration of FOXP3 cDNA in CD34+ cells from an IPEX patient and expression of the introduced FOXP3 transcript in gene-edited primary T cells from both healthy individuals and IPEX patients. Our combined findings suggest that refinement of this approach is likely to provide future clinical benefit in IPEX.

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