Type 1 diabetes (T1D) develops spontaneously despite functional antigen presentation machinery in the thymus and a perceptible central tolerance process. We found that intrathymic enrichment with IL-4 fine tunes signaling through the IL-4/IL-13 heteroreceptor (HR) in early thymic progenitors (ETPs), augments negative selection of self-reactive T cells, sustains a diverse T cell repertoire devoid of clones expressing disease-associated T cell receptor (TCR) genes, and protects the nonobese diabetic (NOD) mouse from T1D. Indeed, optimal IL-4 activates STAT transcription factors to program ETP fate decision toward CD11c+CD8α+ dendritic cells (DCs) agile in negative T cell selection and clonal deletion of diabetogenic T cells. However, due to diminished invariant natural killer T (iNKT) 2 cell frequency in the NOD thymus, IL-4 is as suboptimal level, metering STAT activation to program ETP fate decision toward the T cell lineage leading to diminished negative selection, a clonally restricted TCR repertoire, and manifestation of spontaneous T1D. These insights uncover yet another interplay by which IL-4 affects T1D.
Alexis N. Cattin-Roy, Kimberly G. Laffey, Luan B. Le, Adam G. Schrum, Habib Zaghouani
The development of pathogenic autoreactive CD4+ T cells, particularly in the context of impaired signaling, remains poorly understood. Unraveling how defective signaling pathways contribute to their activation and persistence is crucial for identifying new therapeutic targets. We profiled a highly arthritogenic subset of naïve CD4+ T cells using bulk and single-cell RNA and TCR sequencing from SKG mice, which develop CD4+ T cell mediated autoimmune arthritis driven by a hypomorphic mutation in Zap70—a key TCR signaling kinase. Despite impaired signaling, these cells exhibit heightened expression of T cell activation and cytokine signaling genes, but diminished expression of a subset of tolerogenic markers (Izumo1r, Tnfrsf9, Cd5, S100a11) compared to wild-type cells. The arthritogenic cells show an enrichment for TCR variable beta (Vβ) chains targeting superantigens from the endogenous mouse mammary tumor virus (MMTV) but exhibit diminished induction of tolerogenic markers following peripheral antigen encounter, contrasting with the robust induction of negative regulators seen in wild-type cells. In arthritic joints, cells expressing superantigen-reactive Vβs expand alongside detectable MMTV proviruses. Antiretroviral treatment and superantigen-reactive T cell depletion curtail SKG arthritis, suggesting that endogenous retroviruses disrupt peripheral tolerance and promote the activation and differentiation of self-reactive CD4+ T cells into pathogenic effector cells.
Elizabeth E. McCarthy, Steven Yu, Noah Perlmutter, Yuka Nakao, Ryota Naito, Charles Lin, Vivienne Riekher, Joe DeRisi, Chun Jimmie Ye, Arthur Weiss, Judith F. Ashouri
Hannes Vietzen, Laura M. Kühner, Sarah M. Berger, Philippe L. Furlano, Gabriel Bsteh, Thomas Berger, Paulus Rommer, Elisabeth Puchhammer-Stöckl
Patients heterozygous for germline CBL loss-of-function (LOF) variants can develop myeloid malignancy, autoinflammation, or both, if some or all of their leukocytes become homozygous for these variants through somatic loss of heterozygosity (LOH) via uniparental isodisomy. We observed an upregulation of the inflammatory gene expression signature in whole blood from these patients, mimicking monogenic inborn errors underlying autoinflammation. Remarkably, these patients had constitutively activated monocytes that secreted 10 to 100 times more inflammatory cytokines than those of healthy individuals and CBL LOF heterozygotes without LOH. CBL-LOH hematopoietic stem and progenitor cells (HSPCs) outgrew the other cells, accounting for the persistence of peripheral monocytes homozygous for the CBL LOF variant. ERK pathway activation was required for the excessive production of cytokines by both resting and stimulated CBL-LOF monocytes, as shown in monocytic cell lines. Finally, we found that about 1 in 10,000 individuals in the UK Biobank were heterozygous for CBL LOF variants and that these carriers were at high risk of hematological and inflammatory conditions.
Jonathan Bohlen, Ivan Bagarić, Taja Vatovec, Masato Ogishi, Syed F. Ahmed, Axel Cederholm, Lori Buetow, Steicy Sobrino, Corentin Le Floc’h, Carlos A. Arango-Franco, Luis Seabra, Marine Michelet, Federica Barzaghi, Davide Leardini, Francesco Saettini, Francesca Vendemini, Francesco Baccelli, Albert Catala, Eleonora Gambineri, Marinella Veltroni, Yurena Aguilar de la Red, Gillian I. Rice, Filippo Consonni, Laureline Berteloot, Laetitia Largeaud, Francesca Conti, Cécile Roullion, Cécile Masson, Boris Bessot, Yoann Seeleuthner, Tom Le Voyer, Darawan Rinchai, Jérémie Rosain, Anna-Lena Neehus, Lucia Erazo-Borrás, Hailun Li, Zarah Janda, En-Jui Cho, Edoardo Muratore, Camille Soudée, Candice Lainé, Eric Delabesse, Claire Goulvestre, Cindy S. Ma, Anne Puel, Stuart G. Tangye, Isabelle André, Christine Bole-Feysot, Laurent Abel, Miriam Erlacher, Shen-Ying Zhang, Vivien Béziat, Chantal Lagresle-Peyrou, Emmanuelle Six, Marlène Pasquet, Laia Alsina, Alessandro Aiuti, Peng Zhang, Yanick J. Crow, Nils Landegren, Riccardo Masetti, Danny T. Huang, Jean-Laurent Casanova, Jacinta Bustamante
CD8+ T cells destroy insulin-producing pancreatic β cells in type 1 diabetes through HLA class I–restricted presentation of self-antigens. Combinatorial peptide library screening was used to produce a preferred peptide recognition landscape for a patient-derived T cell receptor (TCR) that recognized the preproinsulin-derived (PPI-derived) peptide sequence LWMRLLPLL in the context of disease risk allele HLA A*24:02. Data were used to generate a strong superagonist peptide, enabling production of an autoimmune HLA A*24:02–peptide–TCR structure by crystal seeding. TCR binding to the PPI epitope was strongly focused on peptide residues Arg4 and Leu5, with more flexibility at other positions, allowing the TCR to strongly engage many peptides derived from pathogenic bacteria. We confirmed an epitope from Klebsiella that was recognized by PPI-reactive T cells from 3 of 3 HLA A*24:02+ patients. Remarkably, the same epitope selected T cells from 7 of 8 HLA A*24+ healthy donors that cross-reacted with PPI, leading to recognition and killing of HLA A*24:02+ cells expressing PPI. These data provide a mechanism by which molecular mimicry between pathogen and self-antigens could have resulted in the breaking of self-tolerance to initiate disease.
Garry Dolton, Anna Bulek, Aaron Wall, Hannah Thomas, Jade R. Hopkins, Cristina Rius, Sarah A.E. Galloway, Thomas Whalley, Li Rong Tan, Théo Morin, Nader Omidvar, Anna Fuller, Katie Topley, Md Samiul Hasan, Shikha Jain, Nirupa D’Souza, Thomas Hodges-Hoyland, the TIRID Consortium, Owen B. Spiller, Deborah Kronenberg-Versteeg, Barbara Szomolay, Hugo A. van den Berg, Lucy C. Jones, Mark Peakman, David K. Cole, Pierre J. Rizkallah, Andrew K. Sewell
Multiple Sclerosis (MS) is a chronic disease characterized by dysregulated self-reactive immune responses that damage the neurons’ myelin sheath, leading to progressive disability. The primary therapeutic option, immunosuppressants, inhibits pathogenic anti-myelin responses but depresses the immune system. Antigen-specific monocyte-derived autologous tolerogenic dendritic cells (tolDCs) offer alternative therapeutic approaches to restore tolerance to auto-antigens without causing generalized immunosuppression. However, immune dysregulation in MS could impact the properties of the monocytes used as starting material for this cell therapy. Here, we characterized CD14+ monocytes, mature dendritic cells (mDCs) and Vitamin-D3-tolDCs (VitD3-tolDCs) from active, treatment-naive MS patients and healthy donors (HD). Using multi-omics, we identified a switch in these cell types towards proinflammatory features characterized by alterations in the AhR and NF-kB pathways. MS patient-derived VitD3-tolDCs showed reduced tolerogenic properties compared to those from HD, which were fully restored through direct AhR agonism and using in vivo or in vitro Dimethyl Fumarate (DMF) supplementation. Additionally, in the experimental autoimmune encephalomyelitis (EAE) mouse model, combined therapy of DMF and VitD3-tolDCs was more efficient than monotherapies in reducing the clinical score of mice. We propose that a combined therapy with DMF and VitD3-tolDCs offers enhanced therapeutic potential in treating MS.
Federico Fondelli, Jana Willemyns, Roger Domenech-Garcia, Maria José Mansilla, Gerard Godoy-Tena, Anna G. Ferreté-Bonastre, Alex Agúndez-Moreno, Silvia Presas-Rodriguez, Cristina Ramo-Tello, Esteban Ballestar, Eva Martínez-Cáceres
BACKGROUND. Teplizumab, a FcR non-binding anti-CD3 mAb, is approved to delay progression of type 1 diabetes (T1D) at-risk patients. Previous investigations described the immediate effects of the 14-day treatment, but longer-term effects of the drug remain unknown. METHODS. With an extended analysis of study participants, we found that 36% were undiagnosed or remained clinical diabetes free after 5 years suggesting operational tolerance. Using single cell RNA-seq, we compared the phenotypes, transcriptome, and repertoire of peripheral blood CD8+ T cells including autoreactive T cells from study participants before and after teplizumab and features of responders and non-responders. RESULTS. At 3 months, there were transcriptional signatures of cell activation in CD4+ and CD8+ T cells including signaling that was reversed at 18 months. At that time, there was reduced expression of genes in T cell receptor and activation pathways in clinical responders. In CD8+ T cells, we found increased expression of genes associated with exhaustion and immune regulation with teplizumab treatment. These transcriptional features were further confirmed in an independent cohort. Pseudotime analysis showed differentiation of CD8+ exhausted and memory cells with teplizumab treatment. IL7R expression was reduced and patients with lower expression of CD127 had longer diabetes free intervals. In addition, the frequency of autoantigen reactive CD8+ T cells, that expanded in the placebo group over 18 months, did not increase in the teplizumab group. CONCLUSION. These findings indicate that teplizumab promotes operational tolerance in T1D, involving activation followed by exhaustion and regulation and prevents expansion of autoreactive T cells. TRIAL REGISTRATION. ClinicalTrials.gov: NCT01030861. FUNDING. NIDDK/NIH, Juvenile Diabetes Research Foundation.
Ana Lledó-Delgado, Paula Preston-Hurlburt, Sophia Currie, Pamela Clark, Peter S. Linsley, S. Alice Long, Can Liu, Galina Koroleva, Andrew J. Martins, John S. Tsang, Kevan C. Herold
Inflammatory neuropathies, which include chronic inflammatory demyelinating polyneuropathy (CIDP) and Guillain Barré syndrome (GBS), result from autoimmune destruction of the PNS and are characterized by progressive weakness and sensory loss. CD4+ T cells play a key role in the autoimmune destruction of the PNS. Yet, key properties of pathogenic CD4+ T cells remain incompletely understood. Here, we used paired single-cell RNA-Seq (scRNA-Seq) and single-cell T cell receptor–sequencing (scTCR-Seq) of peripheral nerves from an inflammatory neuropathy mouse model to identify IL-21–expressing CD4+ T cells that were clonally expanded and multifunctional. These IL-21–expressing CD4+ T cells consisted of 2 transcriptionally distinct expanded cell populations, which expressed genes associated with T follicular helper (Tfh) and T peripheral helper (Tph) cell subsets. Remarkably, TCR clonotypes were shared between these 2 IL-21–expressing cell populations, suggesting a common lineage differentiation pathway. Finally, we demonstrated that IL-21 receptor–KO (IL-21R–KO) mice were protected from neuropathy development and had decreased immune infiltration into peripheral nerves. IL-21 signaling upregulated CXCR6, a chemokine receptor that promotes CD4+ T cell localization in peripheral nerves. Together, these findings point to IL-21 signaling, Tfh/Tph differentiation, and CXCR6-mediated cellular localization as potential therapeutic targets in inflammatory neuropathies.
Maryamsadat Seyedsadr, Madison F. Bang, Ethan C. McCarthy, Shirley Zhang, Ho-Chung Chen, Mahnia Mohebbi, Willy Hugo, Jason K. Whitmire, Melissa G. Lechner, Maureen A. Su
Background: Antibiotic-Refractory Lyme Arthritis (ARLA) involves a complex interplay of T cell responses targeting Borrelia burgdorferi antigens succeeding towards autoantigens by epitope spreading. However, the precise molecular mechanisms driving the pathogenic T cell response in ARLA remain unclear. Our aim was to elucidate the molecular program of disease-specific Th cells. Methods: Using flow cytometry, high-throughput T cell receptor (TCR) sequencing and scRNA-seq of CD4+ Th cells isolated from the joints of European ARLA patients, we aimed at inferring antigen specificity through unbiased analysis of TCR repertoire patterns, identifying surrogate markers for disease-specific TCRs and connecting TCR specificity to transcriptional patterns. Results: PD-1hiHLA-DR+CD4+ effector T cells were clonally expanded within the inflamed joints and persisted throughout disease course. Among these cells, we identified a distinct TCRβ motif restricted to HLA-DRB1*11 or *13 alleles. These alleles, being underrepresented in North American ARLA patients, were unexpectedly prevalent in our European cohort. The identified TCRβ motif served as surrogate marker for a convergent TCR response specific to ARLA, distinguishing it from other rheumatic diseases. In the scRNA-seq dataset, the TCRβ motif particularly mapped to peripheral T helper (TPH) cells displaying signs of sustained proliferation, continuous TCR signaling, and expressing CXCL13 and IFN-γ. Conclusion: By inferring disease-specific TCRs from synovial T cells we identified a convergent TCR response in the joints of ARLA patients that continuously fueled the expansion of TPH cells expressing a pathogenic cytokine effector program. The identified TCRs will aid in uncovering the major antigen targets of the maladaptive immune response. Funding: Supported by the German Research Foundation (DFG) MO 2160/4-1; the Federal Ministry of Education and Research (BMBF; Advanced Clinician Scientist-Program INTERACT; 01EO2108) embedded in the Interdisciplinary Center for Clinical Research (IZKF) of the University Hospital Würzburg; the German Center for Infection Research (DZIF; Clinical Leave Program; TI07.001_007) and the Interdisciplinary Center for Clinical Research (IZKF) Würzburg (Clinician Scientist Program, Z-2/CSP-30).
Johannes Dirks, Jonas Fischer, Julia Klaussner, Christine Hofmann, Annette Holl-Wieden, Viktoria Buck, Christian Klemann, Hermann J. Girschick, Ignazio Caruana, Florian Erhard, Henner Morbach
Immunoglobulin G4-related disease (IgG4-RD) is a systemic immune-mediated’ fibroinflammatory disease. The pathomechanisms remain poorly understood. Here, we identified gene variants in familial IgG4-RD and determined their functional consequences. All three affected members shared mutations of the transcription factor IKAROS, encoded by IKZF1, and the E3 ubiquitin ligase UBR4. The IKAROS mutation increased binding to the FYN promoter resulting in higher transcription of FYN in T cells. The UBR4 mutation prevented the lysosomal degradation of the phosphatase CD45. In the presence of elevated FYN, CD45 functioned as a positive regulatory loop, lowering the threshold for T cell activation. Consequently, T cells from affected family members were hyperresponsive to stimulation. When transduced with a low avidity, autoreactive T cell receptor, they responded to the autoantigenic peptide. In parallel, the high expression of FYN in T cells biased their differentiation towards TH2 polarization by stabilizing the transcription factor JunB. This bias is consistent with the frequent atopic manifestations in IgG4-RD patients including our afflicted family members. Building on the functional consequences of these two mutations, we propose a disease model that is not only instructive for IgG4-RD but also for atopic diseases for autoimmune diseases associated with an IKZF1 risk haplotype.
Qingxiang Liu, Yanyan Zheng, Ines Sturmlechner, Abhinav Jain, Maryam Own, Qiankun Yang, Huimin Zhang, Filippo Pinto e Vairo, Karen Cerosaletti, Jane H. Buckner, Kenneth J. Warrington, Matthew J. Koster, Cornelia M. Weyand, Jorg J. Goronzy
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