Khosravi-Maharlooei, Mohsen

ABSTRACT Type 1 Diabetes ( T1D ) is an autoimmune disorder marked by the immune‐mediated destruction of pancreatic β‐cells, resulting in insulin deficiency and dysregulated glucose control. Current therapies—such as insulin replacement and artificial pancreas systems—manage symptoms but fail to restore endogenous β‐cell function or halt disease progression. Transplantation strategies, including islet allo‐ and xenotransplantation, offer potential cures but remain limited by immune rejection, donor scarcity, and the adverse effects of systemic immunosuppression. Within the framework of predictive, preventive, and personalised medicine (3 PM), T1D management requires a paradigm shift towards early detection, targeted prevention, and individualised therapy. Predictive biomarkers and molecular phenotyping can identify high‐risk individuals and forecast graft outcomes, while preventive strategies—such as localised immunomodulation, bioenergetic support, and control of systemic inflammation—improve tolerance and graft longevity. Personalised interventions, including patient‐specific biomaterials, immunoprotective encapsulation, and regulatory T cell–based or stem‐cell–derived β‐cell replacement, address immune and metabolic heterogeneity. Recent progress in biomaterials, encapsulation, and 3D bioprinting enables the practical implementation of this 3 PM approach by enhancing oxygenation, vascular integration, and specific scaffold design. Integration of AI‐driven analytics, digital health monitoring, and multi‐modal diagnostics further supports predictive control of transplant outcomes. This review highlights advances in islet transplantation and regenerative biomaterial engineering as key enablers of the transition from reactive treatment to 3 PM‐guided, patient‐tailored therapy for T1D .

Autoimmune diseases arise from a breakdown of immune tolerance and complex interplay of genetic susceptibility, environmental triggers, tissue-specific immune responses, microbiota, and regulatory pathways. Mouse models remain essential for dissecting these mechanisms, but no single model fully reproduces the heterogeneity, chronicity, and immune complexity of autoimmune disease in humans. This review summarizes classical murine and humanized mouse models used to study inflammatory bowel disease (IBD), multiple sclerosis (MS), type-1 diabetes (T1D), and rheumatoid arthritis (RA). We also highlight disease-specific scoring systems, including clinical indices, histopathology, imaging, cytokine profiling, autoantibody assessment, and human immune-cell readouts, as essential tools for standardized interpretation. Conventional murine models provide experimental control and mechanistic clarity, whereas humanized models improve assessment of human immune responses, patient-specific biology, and therapeutic translation. However, humanized systems remain limited by incomplete immune reconstitution, graft-versus-host disease, donor variability, cost, and incomplete tissue architecture. By providing a comparative framework spanning both conventional and humanized models, this review aims to guide informed model selection tailored to specific research questions in autoimmune disease biology and translational therapeutic development.

Abstract Adoptive T-cell therapies using tumour-specific T-cell receptors (TCRs) are limited by competition with endogenous receptors, which impairs efficacy and poses risks of off-target autoreactivity. Here we present a CRISPR-based platform that completely and selectively eliminates both endogenous TCR-α and -β chains without affecting introduced transgenic TCRs, irrespective of codon optimization. This approach achieves >90% deletion efficiency in Jurkat and primary human T cells, markedly enhancing the expression, pairing fidelity, and functional potency of transgenic receptors. Using a clinically relevant HLA-A*02:01-restricted DMF5 TCR, we show that dual TCR ablation boosts antigen-specific activation and cytotoxicity in vitro and significantly enhances tumor clearance in vivo in human immune system (HIS) mice, while preventing graft-versus-host disease (GVHD). Targeted locus amplification revealed that CRISPR-induced double-strand breaks did not alter lentiviral integration profiles, confirming genomic safety. Extending this approach to four insulin-reactive TCRs demonstrated that removal of endogenous receptors increased transduction efficiency and functional activity, with one (1E6) showing selective activation and infiltration of stem cell–derived islet grafts (SC-islets) in vivo . This study establishes a universal, safe, and scalable genome-editing platform for generating functionally precise human T cells. By integrating cancer immunotherapy and autoimmune disease modelling within a single framework, it provides a strong preclinical rationale for dual endogenous TCR removal as a route to improved specificity, safety, and therapeutic efficacy in TCR-based cell therapies.

ABSTRACT We report the optimization of a 38‐parameter spectral flow cytometry panel to identify, phenotype, and assess lineage plasticity of human regulatory T cells (Tregs). Tregs are an indispensable T cell lineage with pleiotropic tolerogenic functions whose activities contribute critically to numerous disease settings including cancer, autoimmunity, and infectious disease, among others. Phenotypic and functional heterogeneity within the Treg lineage has been appreciated, but the etiology and impact of Treg plasticity across disease states remain incompletely understood. Better tools are thus needed to deeply characterize human Treg phenotypic heterogeneity at the single cell level to advance discovery of Treg‐based biomarkers in disease and to assess the effects of Treg‐directed therapeutics. To this end, our 38‐parameter panel consists of a 13‐marker PBMC backbone module to broadly phenotype PBMCs while specifically discriminating Tregs, and a 25‐marker Treg phenotyping module to determine Treg differentiation state, activation profile, and lineage subtype. In contrast to many high‐parameter OMIPs that rely on surface staining only, we incorporated several intracellular targets in this panel. This afforded the opportunity to thoroughly evaluate binding characteristics of all antibodies in both pre‐fixation and post‐fixation and permeabilization settings; we identify several antibodies eligible for overnight post‐fixation staining that require substantially reduced titers as compared to traditional pre‐fixation staining, resulting in significant cost savings. Dimensionality reduction and semi‐supervised clustering on healthy donor PBMC‐derived Tregs profiled by our panel reveal up to 14 discrete Treg phenotypes. In sum, this panel enables deep phenotypic characterization of human Treg heterogeneity in peripheral blood specimens by spectral flow cytometry.

Human immune system (HIS) mice constructed in various ways are widely used for investigations of human immune responses to pathogens, transplants, and immunotherapies. In HIS mice that generate T cells de novo from hematopoietic progenitors, T cell-dependent multisystem autoimmune disease occurs, most rapidly when the human T cells develop in the native NOD.Cg- Prkdc scid Il2rg tm1Wjl (NSG) mouse thymus, where negative selection is abnormal. Disease develops very late when human T cells develop in human fetal thymus grafts, where robust negative selection is observed. We demonstrate here that PD-1 + CD4 + peripheral (Tph) helper-like and follicular (Tfh) helper-like T cells developing in HIS mice can induce autoimmune disease. Tfh-like cells were more prominent in HIS mice with a mouse thymus, in which the highest levels of IgG were detected in plasma, compared to those with a human thymus. While circulating IgG and IgM antibodies were autoreactive to multiple mouse antigens, in vivo depletion of B cells and antibodies did not delay the development of autoimmune disease. Conversely, adoptive transfer of enriched Tfh- or Tph-like cells induced disease and autoimmunity-associated B cell phenotypes in recipient mice containing autologous human APCs without T cells. Tfh/Tph cells from mice with a human thymus expanded and induced disease more rapidly than those originating in a murine thymus, implicating HLA-restricted T cell-APC interactions in this process. Since Tfh, Tph, autoantibodies, and lymphopenia-induced proliferation (LIP) have all been implicated in various forms of human autoimmune disease, the observations here provide a platform for the further dissection of human autoimmune disease mechanisms and therapies.

Abstract Human immune system (HIS) mice constructed in various ways are widely used for investigations of human immune responses to pathogens, transplants and immunotherapies. In HIS mice that generate T cells de novo from hematopoietic progenitors, T cell-dependent multisystem autoimmune disease occurs, most rapidly when the human T cells develop in the native NOD.Cg- Prkdcscid Il2rgtm1Wjl (NSG) mouse thymus, where negative selection is abnormal. Disease develops very late when human T cells develop in human fetal thymus grafts, where robust negative selection is observed. We demonstrate here that PD-1+CD4+ peripheral (Tph) helper-like and follicular (Tfh) helper-like T cells developing in HIS mice can induce autoimmune disease. Tfh- like cells were more prominent in HIS mice with a mouse thymus, in which the highest levels of IgG were detected in plasma, compared to those with a human thymus. While circulating IgG and IgM antibodies were autoreactive to multiple mouse antigens, in vivo depletion of B cells and antibodies did not delay the development of autoimmune disease. Conversely, adoptive transfer of enriched Tfh- or Tph-like cells induced disease and autoimmunity-associated B cell phenotypes in recipient mice containing autologous human APCs without T cells. Tfh/Tph cells from mice with a human thymus expanded and induced disease more rapidly than those originating in a murine thymus, implicating HLA-restricted T cell-APC interactions in this process. Since Tfh, Tph, autoantibodies and lymphopenia-induced proliferation (LIP) have all been implicated in various forms of human autoimmune disease, the observations here provide a platform for the further dissection of human autoimmune disease mechanisms and therapies.

Human Immune System (HIS) mice constructed with mature human immune cells or with human hematopoietic stem cells and thymic tissue have provided an important tool for human immunological research. In this article, we first review the different types of HIS mice based on human tissues transplanted and sources of the tissues. We then focus on knowledge of human T cell development and responses obtained using HIS mouse models. These areas include the development of human T cell subsets, with a focus on αβ conventional T cells and regulatory T cells, and human T cell responses in the settings of infection, transplantation rejection and tolerance, autoimmune disease, cancer immunotherapy, and regulatory T cell therapy. We also discuss the limitations and potential future applications of HIS mouse models.

Abstract Human immune system (HIS) mice constructed in various ways are widely used for investigations of human immune responses to pathogens, transplants and immunotherapies. In HIS mice that generate T cells de novo from hematopoietic progenitors, T cell-dependent multisystem autoimmune disease occurs, most rapidly when the human T cells develop in the native NOD.Cg- Prkdcscid Il2rgtm1Wjl (NSG) mouse thymus, where negative selection is abnormal. Disease develops very late when human T cells develop in human fetal thymus grafts, where robust negative selection is observed. We demonstrate here that PD-1+CD4+ peripheral (Tph) helper-like and follicular (Tfh) helper-like T cells developing in HIS mice can induce autoimmune disease. Tfh-like cells were more prominent in HIS mice with a mouse thymus, in which the highest levels of IgG were detected in plasma, compared to those with a human thymus. While circulating IgG and IgM antibodies were autoreactive to multiple mouse antigens, in vivo depletion of B cells and antibodies did not delay the development of autoimmune disease. Conversely, adoptive transfer of enriched Tfh- or Tph-like cells induced disease and autoimmunity-associated B cell phenotypes in recipient mice containing autologous human APCs without T cells. T cells from mice with a human thymus expanded and induced disease more rapidly than those originating in a murine thymus, implicating HLA-restricted T cell-APC interactions in this process. Since Tfh, Tph, autoantibodies and LIP have all been implicated in various forms of human autoimmune disease, the observations here provide a platform for the further dissection of human autoimmune disease mechanisms and therapies.

Human immune system (HIS) mice constructed in various ways are widely used for investigations of human immune responses to pathogens, transplants, and immunotherapies. In HIS mice that generate T cells de novo from hematopoietic progenitors, T cell-dependent multisystem autoimmune disease occurs, most rapidly when the human T cells develop in the native NOD.Cg- Prkdc scid Il2rg tm1Wjl (NSG) mouse thymus, where negative selection is abnormal. Disease develops very late when human T cells develop in human fetal thymus grafts, where robust negative selection is observed. We demonstrate here that PD-1 + CD4 + peripheral (Tph) helper-like and follicular (Tfh) helper-like T cells developing in HIS mice can induce autoimmune disease. Tfh-like cells were more prominent in HIS mice with a mouse thymus, in which the highest levels of IgG were detected in plasma, compared to those with a human thymus. While circulating IgG and IgM antibodies were autoreactive to multiple mouse antigens, in vivo depletion of B cells and antibodies did not delay the development of autoimmune disease. Conversely, adoptive transfer of enriched Tfh- or Tph-like cells induced disease and autoimmunity-associated B cell phenotypes in recipient mice containing autologous human APCs without T cells. Tfh/Tph cells from mice with a human thymus expanded and induced disease more rapidly than those originating in a murine thymus, implicating HLA-restricted T cell-APC interactions in this process. Since Tfh, Tph, autoantibodies, and lymphopenia-induced proliferation (LIP) have all been implicated in various forms of human autoimmune disease, the observations here provide a platform for the further dissection of human autoimmune disease mechanisms and therapies.