RESUMO
Autoimmune diseases are commonly associated with a polygenic inheritance pattern. In rare instances, causal monogenic variants have been identified. The study by Liu et al. in this issue of the JCI provides an example of monogenic variants occurring in patients with IgG4-related disease (IgG4-RD). The authors investigated a familial cluster of IgG4-RD that consisted of an affected father and two daughters; the mother was unaffected. Genome sequencing of this quad identified a variant in IKZF1 (encoding IKAROS) and another variant in UBR4 (encoding E3 ubiquitin ligase). Both variants were present in the father and both daughters but absent in the unaffected mother. Using multidimensional profiling of immune cells and functional experiments in primary cells, the authors determined a molecular pathway contributing to T cell activation in IgG4-RD. Importantly, the characterization of these variants provides insights into pathogenic mechanisms in IgG4-RD and, potentially, other autoimmune diseases.
Assuntos
Fator de Transcrição Ikaros , Doença Relacionada a Imunoglobulina G4 , Ubiquitina-Proteína Ligases , Humanos , Doença Relacionada a Imunoglobulina G4/genética , Doença Relacionada a Imunoglobulina G4/imunologia , Doença Relacionada a Imunoglobulina G4/patologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/imunologia , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/imunologia , Feminino , Masculino , Imunoglobulina G/imunologia , Imunoglobulina G/genética , Linfócitos T/imunologia , Linfócitos T/patologia , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Variação GenéticaRESUMO
IgG4-related disease (IgG4-RD) is a systemic immune-mediated fibroinflammatory disease whose pathomechanisms remain poorly understood. Here, we identified gene variants in familial IgG4-RD and determined their functional consequences. All 3 affected members of the family shared variants of the transcription factor IKAROS, encoded by IKZF1, and the E3 ubiquitin ligase UBR4. The IKAROS variant increased binding to the FYN promoter, resulting in higher transcription of FYN in T cells. The UBR4 variant 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 the affected family members were hyperresponsive to stimulation. When transduced with a low-avidity, autoreactive T cell receptor, their T cells responded to the autoantigenic peptide. In parallel, high expression of FYN in T cells biased their differentiation toward Th2 polarization by stabilizing the transcription factor JunB. This bias was consistent with the frequent atopic manifestations in patients with IgG4-RD, including the affected family members in the present study. Building on the functional consequences of these 2 variants, we propose a disease model that is not only instructive for IgG4-RD but also for atopic diseases and autoimmune diseases associated with an IKZF1 risk haplotype.
Assuntos
Autoimunidade , Fator de Transcrição Ikaros , Células Th2 , Ubiquitina-Proteína Ligases , Humanos , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/imunologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/imunologia , Autoimunidade/genética , Células Th2/imunologia , Células Th2/patologia , Feminino , Masculino , Doença Relacionada a Imunoglobulina G4/genética , Doença Relacionada a Imunoglobulina G4/imunologia , Doença Relacionada a Imunoglobulina G4/patologia , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-fyn/genética , Proteínas Proto-Oncogênicas c-fyn/imunologia , LinhagemRESUMO
Treg therapy holds promise as a potentially curative approach to establish immune tolerance in transplantation and autoimmune disease. An outstanding question is whether therapeutic Tregs have the potential to transdifferentiate into effector T-cells and, thus, exacerbate rather than suppress immune responses. In mice, the transcription factor Helios is thought to promote Treg lineage stability in a range of inflammatory contexts. In humans, the role of Helios in Tregs is less clear, in part, due to the inability to enrich and study subsets of Helios-positive versus Helios-negative Tregs. Using an in vitro expansion system, we found that loss of high Helios expression and emergence of an intermediate Helios (Heliosmid )-expressing population correlated with Treg destabilization. We used CRISPR/Cas9 to genetically ablate Helios expression in human naive or memory Tregs and found that Helios-KO and unedited Tregs were equivalent in their suppressive function and stability in inflammation. Thus, high Helios expression is a marker, but not a driver, of human Treg stability in vitro. These data highlight the importance of monitoring Helios expression in therapeutic Treg manufacturing and provide new insight into the biological function of this transcription factor in human T-cells.
Assuntos
Antígenos de Diferenciação/imunologia , Regulação da Expressão Gênica/imunologia , Fator de Transcrição Ikaros/imunologia , Linfócitos T Reguladores/imunologia , Animais , Antígenos de Diferenciação/genética , Sistemas CRISPR-Cas , Linhagem Celular , Técnicas de Inativação de Genes , Humanos , Fator de Transcrição Ikaros/genética , CamundongosRESUMO
The Ikaros family transcription factors regulate lymphocyte development. Loss-of-function variants in IKZF1 cause primary immunodeficiency, but Ikaros family members IKZF2 and IKZF3 have not yet been associated with immunodeficiency. Here, we describe a pedigree with a heterozygous truncating variant in IKZF2, encoding the transcriptional activator and repressor Helios, which is highly expressed in regulatory T cells and effector T cells, particularly of the CD8+ T cell lineage. Protein-protein interaction analysis revealed that the variant abolished heterodimerization of Helios with Ikaros and Aiolos and also prevented Helios binding to members of the Mi-2/NuRD chromatin remodeling complex. Patients carrying the IKZF2 variant presented with a combined immunodeficiency phenotype characterized by recurrent upper respiratory infections, thrush and mucosal ulcers, and chronic lymphadenopathy. With extensive immunophenotyping, functional assays, and transcriptional analysis, we show that reduced Helios expression was associated with chronic T cell activation and increased production of proinflammatory cytokines both in effector and regulatory T cells. Lymph node histology from patients indicated dysregulated germinal center reactions. Moreover, affected individuals displayed a profound reduction in circulating MAIT cell numbers. In summary, we show that this previously undescribed loss-of-function variant in Helios leads to an immunodeficiency with signs of immune overactivation.
Assuntos
Fator de Transcrição Ikaros/imunologia , Células T Invariantes Associadas à Mucosa/imunologia , Adulto , Idoso , Feminino , Centro Germinativo/imunologia , Humanos , Fator de Transcrição Ikaros/sangue , Fator de Transcrição Ikaros/genética , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Helios, a member of the Ikaros family of transcription factors, is predominantly expressed in developing thymocytes, activated T cells, and regulatory T cells (Tregs). Studies in mice have emphasized its role in maintenance of Treg immunosuppressive functions by stabilizing Foxp3 expression and silencing the Il2 locus. However, its contribution to human immune homeostasis and the precise mechanisms by which Helios regulates other T cell subsets remain unresolved. Here, we investigated a patient with recurrent respiratory infections and hypogammaglobulinemia and identified a germline homozygous missense mutation in IKZF2 encoding Helios (p.Ile325Val). We found that HeliosI325V retains DNA binding and dimerization properties but loses interaction with several partners, including epigenetic remodelers. Whereas patient Tregs showed increased IL-2 production, patient conventional T cells had decreased accessibility of the IL2 locus and consequently reduced IL-2 production. Reduced chromatin accessibility was not exclusive to the IL2 locus but involved a variety of genes associated with T cell activation. Single-cell RNA sequencing of peripheral blood mononuclear cells revealed gene expression signatures indicative of a shift toward a proinflammatory, effector-like status in patient CD8+ T cells. Moreover, patient CD4+ T cells exhibited a pronounced defect in proliferation with delayed expression of surface checkpoint inhibitors, suggesting an impaired onset of the T cell activation program. Collectively, we identified a previously uncharacterized, germline-encoded inborn error of immunity and uncovered a cell-specific defect in Helios-dependent epigenetic regulation. Binding of Helios with specific partners mediates this regulation, which is ultimately necessary for the transcriptional programs that enable T cell homeostasis in health and disease.
Assuntos
Células Germinativas/imunologia , Fator de Transcrição Ikaros/imunologia , Adolescente , Epigênese Genética/genética , Epigênese Genética/imunologia , Humanos , Fator de Transcrição Ikaros/genética , Interleucina-2/biossíntese , Masculino , Mutação de Sentido Incorreto , Linfócitos T Reguladores/imunologiaRESUMO
Regulatory T cells (Tregs) expressing the Foxp3 transcription factor are indispensable for the maintenance of immune system homeostasis. Tregs may lose Foxp3 expression or be reprogrammed into cells that produce proinflammatory cytokines, for example, Th1-like Tregs, Th2-like Tregs, Th17-like Tregs, and Tfh-like Tregs. Accordingly, selective therapeutic molecules that manipulate Treg lineage stability and/or functional activity might have the potential to improve aberrant immune responses in human disorders. In particular, the transcription factor Helios has emerged as an important marker and modulator of Tregs. Therefore, the current review focuses on recent findings on the expression, function, and mechanisms of Helios, as well as the patterns of Foxp3+ Tregs coexpressing Helios in various human disorders, in order to explore the potential of Helios for the improvement of many immune-related diseases. The studies were selected from PubMed using the library of the Nanjing Medical University in this review. The findings of the included studies indicate that Helios expression stabilizes the phenotype and function of Foxp3+ Tregs in certain inflammatory environments. Further, Tregs coexpressing Helios and Foxp3 were identified as a specific phenotype of stronger suppressor immune cells in both humans and animal models. Importantly, there is ample evidence that Helios-expressing Foxp3+ Tregs are relevant to various human disorders, including connective tissue diseases, infectious diseases, solid organ transplantation-related immunity, and cancer. Thus, Helios+Foxp3+CD4+ Tregs could be a valuable target in human diseases, and their potential should be explored further in the clinical setting.
Assuntos
Doenças Autoimunes/imunologia , Doenças do Tecido Conjuntivo/imunologia , Fatores de Transcrição Forkhead/imunologia , Fator de Transcrição Ikaros/imunologia , Infecções/imunologia , Neoplasias/imunologia , Linfócitos T Reguladores/imunologia , Animais , Doenças Autoimunes/metabolismo , Biomarcadores/metabolismo , Doenças do Tecido Conjuntivo/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Humanos , Fator de Transcrição Ikaros/metabolismo , Infecções/metabolismo , Inflamação/imunologia , Inflamação/metabolismo , Neoplasias/metabolismo , Transplante de Órgãos , Linfócitos T Reguladores/metabolismoRESUMO
PURPOSE: IKAROS, encoded by IKZF1, is a member of the IKAROS family of zinc-finger transcription factors playing critical roles in lymphocyte development, differentiation, and tumor suppression. Several studies demonstrated that IKZF1 mutations affecting DNA binding or homo-/hetero-dimerization are mostly associated with common variable immunodeficiency, combined immunodeficiency, or hematologic manifestations. Herein we report a likely de novo, nonsense IKZF1 mutation (p.C182*) in a baby with low T cell receptor excision circles (TREC) identified by newborn screening testing for severe combined immunodeficiency. The patient also presented a profound B cell deficiency at birth. METHODS: Genetic, functional, immunologic, and clinical outcome data associated with this patient and her mutation were evaluated. RESULTS: Mutant p.C182* was detected in the cytoplasm of the patient's primary cells, in contrast to wild type (WT) IKAROS protein, only detected in the nucleus. Functional in vitro assessments revealed that p.C182* was less stable than WT IKAROS protein and failed to bind to its target DNA binding sequence and dimerize with WT IKAROS protein, resulting in impaired pericentromeric targeting and transcriptional repression by means of haploinsufficiency. During follow-up, while a spontaneous recovery of TREC and T cells was observed, B cells improved but not to sustained normal ranges. CONCLUSIONS: Patients with IKAROS-associated diseases can present with SCID-like TREC values through newborn screening testing. IKZF1 mutations should be added to the low TREC differential, although spontaneous recovery has to be considered.
Assuntos
Haploinsuficiência/genética , Fator de Transcrição Ikaros/genética , Mutação/genética , Imunodeficiência Combinada Severa/diagnóstico , Imunodeficiência Combinada Severa/genética , Linfócitos B/imunologia , Imunodeficiência de Variável Comum/genética , Imunodeficiência de Variável Comum/imunologia , DNA/genética , Células HEK293 , Haploinsuficiência/imunologia , Humanos , Fator de Transcrição Ikaros/imunologia , Recém-Nascido , Triagem Neonatal/métodos , Doenças da Imunodeficiência Primária/genética , Doenças da Imunodeficiência Primária/imunologia , Imunodeficiência Combinada Severa/imunologia , Linfócitos T/imunologiaRESUMO
Regulatory T lymphocytes are important targets for the treatment of acute respiratory distress syndrome (ARDS). IL-35 is a newly identified IL-12 cytokine family member that plays an important protective role in a variety of immune system diseases by regulating Treg cell differentiation; however, the role of IL-35 in the pathogenesis of ARDS is still unclear. Here, we found that IL-35 was significantly elevated in adult patients with ARDS compared to controls. Additionally, IL-35 was positively and significantly correlated with IL-6, IL-10 and the oxygenation index (PaO2/FiO2 ratio) but negatively correlated with TNF-α, IL-1ß and APACHE II score during ARDS. Moreover, the proportion of Treg/CD4+ cells in the peripheral blood of ARDS patients and the expression of NF-κB in PMBCs were significantly higher than in healthy individuals. Recombinant IL-35 improved survival in a murine model of CLP-induced ARDS. Additionally, IL-35 administration decreased the inflammatory response, as reflected by lower levels of cytokines (including IL-2, TNF-α, IL-1ß and IL-6) and less lung damage in CLP-induced ARDS. Furthermore, recombinant IL-35 reduced the apoptosis of lung tissue and the expression of NF-κB signalling in a CLP-induced ARDS model and increased the proportion of Treg cells in spleen and peripheral blood. In vitro experiments revealed that IL-35 can affect the phosphorylation of STAT5 during differentiation of naïve CD4+ T lymphocytes into Foxp3+Helios+ Tregs. Our findings suggest that IL-35 attenuates ARDS by promoting the differentiation of naïve CD4+ T cells into Foxp3+Helios+ Tregs, thereby providing a novel tool for anti-ARDS therapy.
Assuntos
Diferenciação Celular/imunologia , Fatores de Transcrição Forkhead/imunologia , Fator de Transcrição Ikaros/imunologia , Interleucinas/imunologia , Síndrome do Desconforto Respiratório/imunologia , Linfócitos T Reguladores/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Células Cultivadas , Citocinas/imunologia , Feminino , Humanos , Ativação Linfocitária/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-IdadeRESUMO
Hematopoietic stem cells (HSCs) are the progenitor cells that give rise to the diverse repertoire of all immune cells. As they differentiate, HSCs yield a series of cell states that undergo gradual commitment to become mature blood cells. Studies of hematopoiesis in murine models have provided critical insights about the lineage relationships among stem cells, progenitors, and mature cells, and these have guided investigations of the molecular basis for these distinct developmental stages. Primary immune deficiencies are caused by inborn errors of immunity that result in immune dysfunction and subsequent susceptibility to severe and recurrent infection(s). Over the last decade there has been a dramatic increase in the number and depth of the molecular, cellular, and clinical characterization of such genetically defined causes of immune dysfunction. Patients harboring inborn errors of immunity thus represent a unique resource to improve our understanding of the multilayered and complex mechanisms underlying lymphocyte development in humans. These breakthrough discoveries not only enable significant advances in the diagnosis of such rare and complex conditions but also provide substantial improvement in the development of personalized treatments. Here, we will discuss the clinical, cellular, and molecular phenotypes, and treatments of selected inborn errors of immunity that impede, either intrinsically or extrinsically, the development of B- or T-cells at different stages.
Assuntos
Regulação da Expressão Gênica/imunologia , Células-Tronco Hematopoéticas/imunologia , Linfopoese/imunologia , Medicina de Precisão/métodos , Doenças da Imunodeficiência Primária/genética , Animais , Diferenciação Celular , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/imunologia , Terapia Genética/métodos , Hematopoese/genética , Hematopoese/imunologia , Células-Tronco Hematopoéticas/citologia , Humanos , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/imunologia , Janus Quinase 3/genética , Janus Quinase 3/imunologia , Linfócitos/imunologia , Linfócitos/patologia , Linfopoese/genética , Camundongos , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/imunologia , Doenças da Imunodeficiência Primária/patologia , Doenças da Imunodeficiência Primária/terapiaRESUMO
The recent development of successful CAR (chimeric antigen receptor) T cell therapies has been accompanied by a need to better control potentially fatal toxicities that can arise from adverse immune reactions. Here we present a ligand-controlled CAR system, based on the IKZF3 ZF2 ß-hairpin IMiD-inducible degron, which allows for the reversible control of expression levels of type I membrane proteins, including CARs. Testing this system in an established mouse xenotransplantation model for acute lymphoblastic leukemia, we validate the ability of the CAR19-degron to target and kill CD19-positive cells displaying complete control/clearance of the tumor. We also demonstrate that the activity of CAR19-degron can be regulated in vivo when dosing a US Food and Drug Administration-approved drug, lenalidomide.
Assuntos
Fator de Transcrição Ikaros/imunologia , Fatores Imunológicos/farmacologia , Receptores de Antígenos Quiméricos/imunologia , Linfócitos T/imunologia , Adolescente , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Fator de Transcrição Ikaros/química , Fatores Imunológicos/química , Masculino , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos NOD , Camundongos SCID , Pessoa de Meia-Idade , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/patologia , Receptores de Antígenos Quiméricos/genética , Adulto JovemRESUMO
Accumulation of CD103+CD8+ resident memory T (TRM) cells in human lung tumors has been associated with a favorable prognosis. However, the contribution of TRM to anti-tumor immunity and to the response to immune checkpoint blockade has not been clearly established. Using quantitative multiplex immunofluorescence on cohorts of non-small cell lung cancer patients treated with anti-PD-(L)1, we show that an increased density of CD103+CD8+ lymphocytes in immunotherapy-naive tumors is associated with greatly improved outcomes. The density of CD103+CD8+ cells increases during immunotherapy in most responder, but not in non-responder, patients. CD103+CD8+ cells co-express CD49a and CD69 and display a molecular profile characterized by the expression of PD-1 and CD39. CD103+CD8+ tumor TRM, but not CD103-CD8+ tumor-infiltrating counterparts, express Aiolos, phosphorylated STAT-3, and IL-17; demonstrate enhanced proliferation and cytotoxicity toward autologous cancer cells; and frequently display oligoclonal expansion of TCR-ß clonotypes. These results explain why CD103+CD8+ TRM are associated with better outcomes in anti-PD-(L)1-treated patients.
Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Linfócitos T CD8-Positivos/imunologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Neoplasias Pulmonares/imunologia , Linfócitos do Interstício Tumoral/imunologia , Receptor de Morte Celular Programada 1/imunologia , Antígenos CD/genética , Antígenos CD/imunologia , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Antígeno B7-H1/imunologia , Antígenos CD8/genética , Antígenos CD8/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/patologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Citotoxicidade Imunológica/efeitos dos fármacos , Regulação da Expressão Gênica , Humanos , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/imunologia , Memória Imunológica , Imunoterapia/métodos , Cadeias alfa de Integrinas/genética , Cadeias alfa de Integrinas/imunologia , Interleucina-17/genética , Interleucina-17/imunologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidade , Ativação Linfocitária/efeitos dos fármacos , Contagem de Linfócitos , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/patologia , Fosforilação , Prognóstico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/genética , Estudos Retrospectivos , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/imunologia , Transdução de Sinais , Análise de Sobrevida , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologiaRESUMO
The zinc finger protein 36-like 2, ZFP36L2, is a member of a small family of RNA-binding proteins composed by ZFP36 (also known as tristetraprolin, TTP), ZFP36L1 and ZFP36L2 in humans, with corresponding murine orthologs. These proteins bind to adenine uridine-rich element (ARE) in the 3'untranslated region of target messenger RNA and stimulate target degradation. ZFP36 functions as an anti-inflammatory modulator in murine models of inflammatory diseases by down-regulating the production of inflammatory cytokines such as tumor necrosis factor-α. However, how ZFP36L1 and ZFP36L2 alter the function of CD4+ T cells is not completely understood. We addressed this issue by searching for the target genes of ZFP36L2 by comprehensive transcriptome analysis. We observed that ZFP36L2 is highly expressed in naïve CD4+ T cells; however, when CD4+ T cells are stimulated through their T cell receptors, ZFP36L2 expression is rapidly reduced in both humans and mice. Among CD4+ T cell populations, the expression levels of ZFP36L2 in regulatory T cells (Tregs) were significantly lower than those in naïve or effector CD4+ T cells. RNA-sequence analysis revealed that the forced expression of ZFP36L2 decreased Ikzf2 (encoding Helios) expression in Foxp3+ Tregs and inhibited the ability of induced Tregs (iTregs). ZFP36L2 directly bound to and destabilized the 3'untranslated region of Ikzf2 mRNA, which contains AU-rich elements. These results indicate that ZFP36L2 reduces the expression of Ikzf2 and suppresses iTreg function, raising the interesting possibility that the inhibition of ZFP36L2 in iTregs could be a therapeutic strategy for autoimmune diseases.
Assuntos
Proteínas de Ligação a DNA/biossíntese , Regulação da Expressão Gênica/imunologia , Fator de Transcrição Ikaros/biossíntese , Linfócitos T Reguladores/imunologia , Fatores de Transcrição/biossíntese , Fatores de Transcrição/imunologia , Tristetraprolina/imunologia , Animais , Proteínas de Ligação a DNA/imunologia , Regulação para Baixo , Humanos , Fator de Transcrição Ikaros/imunologia , Camundongos , Fatores de Transcrição/metabolismo , Tristetraprolina/metabolismoAssuntos
Fator de Transcrição Ikaros/imunologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Linfócitos T Reguladores/imunologia , Humanos , Neoplasias Pulmonares/imunologia , Carcinoma de Pequenas Células do Pulmão/imunologiaRESUMO
T cell receptor (TCR) stimulation and cytokine cues drive the differentiation of CD4+ naïve T cells into effector T cell populations with distinct proinflammatory or regulatory functions. Unlike adult naïve T cells, human fetal naïve CD4+ T cells preferentially differentiate into FOXP3+ regulatory T (Treg) cells upon TCR activation independent of exogenous cytokine signaling. This cell-intrinsic predisposition for Treg differentiation is implicated in the generation of tolerance in utero; however, the underlying mechanisms remain largely unknown. Here, we identify epigenetic and transcriptional programs shared between fetal naïve T and committed Treg cells that are inactive in adult naïve T cells and show that fetal-derived induced Treg (iTreg) cells retain this transcriptional program. We show that a subset of Treg-specific enhancers is accessible in fetal naïve T cells, including two active superenhancers at Helios Helios is expressed in fetal naïve T cells but not in adult naïve T cells, and fetal iTreg cells maintain Helios expression. CRISPR-Cas9 ablation of Helios in fetal naïve T cells impaired their differentiation into iTreg cells upon TCR stimulation, reduced expression of immunosuppressive genes in fetal iTreg cells such as IL10, and increased expression of proinflammatory genes including IFNG Consequently, Helios knockout fetal iTreg cells had reduced IL-10 and increased IFN-γ cytokine production. Together, our results reveal important roles for Helios in enhancing preferential fetal Treg differentiation and fine-tuning eventual Treg function. The Treg-biased programs identified within fetal naïve T cells could potentially be used to engineer enhanced iTreg populations for adoptive cellular therapies.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Fator de Transcrição Ikaros/imunologia , Linfócitos T Reguladores/imunologia , Adulto , Linfócitos T CD4-Positivos/citologia , Diferenciação Celular/imunologia , Células Cultivadas , Humanos , Linfócitos T Reguladores/citologiaRESUMO
The establishment of a diverse B cell antigen receptor (BCR) repertoire by V(D)J recombination also generates autoreactive B cells. Anergy is one tolerance mechanism; it renders autoreactive B cells insensitive to stimulation by self-antigen, whereas Toll-like receptor (TLR) signaling can reactivate anergic B cells. Here, we describe a critical role of the transcription factor Ikaros in controlling BCR anergy and TLR signaling. Mice with specific deletion of Ikaros in mature B cells developed systemic autoimmunity. Ikaros regulated many anergy-associated genes, including Zfp318, which is implicated in the attenuation of BCR responsiveness by promoting immunoglobulin D expression in anergic B cells. TLR signaling was hyperactive in Ikaros-deficient B cells, which failed to upregulate feedback inhibitors of the MyD88-nuclear factor κB signaling pathway. Systemic inflammation was lost on expression of a non-self-reactive BCR or loss of MyD88 in Ikaros-deficient B cells. Thus, Ikaros acts as a guardian preventing autoimmunity by promoting BCR anergy and restraining TLR signaling.
Assuntos
Autoimunidade/genética , Linfócitos B/imunologia , Anergia Clonal/genética , Fator de Transcrição Ikaros/metabolismo , Receptores Toll-Like/metabolismo , Animais , Linfócitos B/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica/imunologia , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/imunologia , Imunoglobulina D/imunologia , Imunoglobulina D/metabolismo , Camundongos , Modelos Animais , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Receptores de Antígenos de Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Receptores Toll-Like/imunologiaRESUMO
Regulatory T (Treg) cells are a subset of CD4+ T cells that are critical for the maintenance of self-tolerance. The forkhead box transcription factor Foxp3 is a master regulator for the Treg phenotype and function and its expression is essential in Treg cells, as the loss of Foxp3 results in lethal autoimmunity. Two major subsets of Treg cells have been described in vivo; thymus-derived Treg (tTreg) cells that develop in the thymus and peripherally induced Treg (pTreg) cells that are derived from conventional CD4+ Foxp3- T cells and are converted in peripheral tissues to cells that express Foxp3 and acquire suppressive ability. The transcription factor Helios, a member of the Ikaros transcription factor family, is expressed in 60-70% of Treg cells in both mouse and man, and is believed to be a marker of tTreg cells. In this review, we discuss the role and function of Helios in Treg cells, the controversy surrounding the use of Helios as a marker of tTreg cells, and how Helios controls specific aspects of the Treg cell program.
Assuntos
Antígenos de Diferenciação/imunologia , Proteínas de Ligação a DNA/imunologia , Fatores de Transcrição Forkhead/imunologia , Fator de Transcrição Ikaros/imunologia , Linfócitos T Reguladores/imunologia , Fatores de Transcrição/imunologia , Animais , Humanos , CamundongosRESUMO
HIV-1 infection expands large populations of late-stage differentiated CD8 T cells that may persist long after viral escape from TCR recognition. In this study, we investigated whether such CD8 T cell populations can perform unconventional innate-like antiviral effector functions. Chronic untreated HIV-1 infection was associated with elevated numbers of CD45RA+CD57+ terminal effector CD8 T cells expressing FcγRIIIA (CD16). The FcγRIIIA+ CD8 T cells displayed a distinctive transcriptional profile between conventional CD8 T cells and NK cells, characterized by high levels of IKZF2 and low expression of IL7R This transcriptional profile translated into a distinct NKp80+ IL-7Rα- surface phenotype with high expression of the Helios transcription factor. Interestingly, the FcγRIIIA+ CD8 T cells mediated HIV-specific Ab-dependent cellular cytotoxicity (ADCC) activity at levels comparable with NK cells on a per cell basis. The FcγRIIIA+ CD8 T cells were highly activated in a manner that correlated positively with expansion of the CD8 T cell compartment and with plasma levels of soluble mediators of antiviral immunity and inflammation such as IP-10, TNF, IL-6, and TNFRII. The frequency of FcγRIIIA+ CD8 T cells persisted as patients initiated suppressive antiretroviral therapy, although their activation levels declined. These data indicate that terminally differentiated effector CD8 T cells acquire enhanced innate cell-like characteristics during chronic viral infection and suggest that HIV-specific ADCC is a function CD8 T cells use to target HIV-infected cells. Furthermore, as the FcγRIIIA+ CD8 T cells persist in treatment, they contribute significantly to the ADCC-capable effector cell pool in patients on antiretroviral therapy.
Assuntos
Citotoxicidade Celular Dependente de Anticorpos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Fator de Transcrição Ikaros/imunologia , Receptores de IgG/genética , Receptores de Interleucina-7/imunologia , Adolescente , Adulto , Citotoxicidade Celular Dependente de Anticorpos/genética , Linfócitos T CD8-Positivos/patologia , Diferenciação Celular/imunologia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Receptores de IgG/imunologia , Adulto JovemRESUMO
We derived a mouse model in which a mutant form of Nbn/Nbs1mid8 (hereafter Nbnmid8) exhibits severely impaired binding to the Mre11-Rad50 core of the Mre11 complex. The Nbnmid8 allele was expressed exclusively in hematopoietic lineages (in Nbn-/mid8vav mice). Unlike Nbnflox/floxvav mice with Nbn deficiency in the bone marrow, Nbn-/mid8vav mice were viable. Nbn-/mid8vav mice hematopoiesis was profoundly defective, exhibiting reduced cellularity of thymus and bone marrow, and stage-specific blockage of B cell development. Within 6 mo, Nbn-/mid8 mice developed highly penetrant T cell leukemias. Nbn-/mid8vav leukemias recapitulated mutational features of human T cell acute lymphoblastic leukemia (T-ALL), containing mutations in NOTCH1, TP53, BCL6, BCOR, and IKZF1, suggesting that Nbnmid8 mice may provide a venue to examine the relationship between the Mre11 complex and oncogene activation in the hematopoietic compartment. Genomic analysis of Nbn-/mid8vav malignancies showed focal amplification of 9qA2, causing overexpression of MRE11 and CHK1 We propose that overexpression of MRE11 compensates for the metastable Mre11-Nbnmid8 interaction, and that selective pressure for overexpression reflects the essential role of Nbn in promoting assembly and activity of the Mre11 complex.
Assuntos
Hidrolases Anidrido Ácido/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Regulação Leucêmica da Expressão Gênica , Proteína Homóloga a MRE11/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Linfócitos T/imunologia , Hidrolases Anidrido Ácido/imunologia , Animais , Linfócitos B/imunologia , Linfócitos B/patologia , Medula Óssea/imunologia , Medula Óssea/patologia , Proteínas de Ciclo Celular/deficiência , Proteínas de Ciclo Celular/imunologia , Quinase 1 do Ponto de Checagem/genética , Quinase 1 do Ponto de Checagem/imunologia , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/imunologia , Modelos Animais de Doenças , Instabilidade Genômica/imunologia , Hematopoese/genética , Hematopoese/imunologia , Humanos , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/imunologia , Proteína Homóloga a MRE11/imunologia , Camundongos , Camundongos Knockout , Mutação , Leucemia-Linfoma Linfoblástico de Células T Precursoras/imunologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/prevenção & controle , Ligação Proteica , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/imunologia , Receptor Notch1/genética , Receptor Notch1/imunologia , Proteínas Repressoras/genética , Proteínas Repressoras/imunologia , Transdução de Sinais , Linfócitos T/patologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/imunologiaRESUMO
The Ikaros family of transcription factors (TFs) are important regulators of lymphocyte function. However, their roles in human innate lymphoid cell (ILC) function remain unclear. Here, we found that Ikaros (IKZF1) is expressed by all ILC subsets, including NK cells, in blood, tonsil, and gut, while Helios (IKZF2) is preferentially expressed by ILC3 in tonsil and gut. Aiolos (IKZF3) followed the expression pattern of T-bet and Eomes, being predominantly expressed by ILC1 and NK cells. Differentiation of IFN-γ-producing ILC1 and NK cells from ILC3 by IL-1ß plus IL-12-stimulation was associated with upregulation of T-bet and Aiolos. Selective degradation of Aiolos and Ikaros by lenalidomide suppressed ILC1 and NK cell differentiation and expression of ILC1 and NK cell-related transcripts (LEF1, PRF1, GRZB, CD244, NCR3, and IRF8). In line with reduced ILC1/NK cell differentiation, we observed an increase in the expression of the ILC3-related TF Helios, as well as ILC3 transcripts (TNFSF13B, IL22, NRP1, and RORC) and in the frequency of IL-22 producing ILC3 in cultures with IL-1ß and IL-23. These data suggest that suppression of Aiolos and Ikaros expression inhibits ILC1 and NK cell differentiation while ILC3 function is maintained. Hence, our results open up for new possibilities in targeting Ikaros family TFs for modulation of type 1/3 immunity in inflammation and cancer.
Assuntos
Diferenciação Celular/imunologia , Transdiferenciação Celular/imunologia , Fator de Transcrição Ikaros/imunologia , Células Matadoras Naturais/imunologia , Lenalidomida/imunologia , Células Cultivadas , Humanos , Imunidade Inata/imunologia , Fatores Reguladores de Interferon/imunologia , Interleucina-12/imunologia , Interleucina-1beta/imunologia , Linfócitos/imunologiaRESUMO
BACKGROUND/AIMS: Rheumatoid arthritis (RA) is a progressive, chronic, even disabling systemic autoimmune disease. Imbalance between pathogenic immune cells and immunosuppressive cells is associated with the pathogenesis and development of RA and other autoimmune diseases. As Foxp3 is also expressed on activated CD4+ cells in the presence of inflammation, the identification of Treg cells in patients with RA remains a challenge. METHODS: Comprehensive analyses were carried out by Flow cytometry. Expression of Helios, CD226, T cell immunoreceptor with Ig and ITIM domains clinical samples and healthy controls. RESULTS: We have systemically examined three potential markers, Helios, CD226 and TIGIT, that are possibly related to Treg identification, and found that Helios expression on CD4+Foxp3+cells was decreased and negatively correlated with the disease activity of RA patients, while CD226 and TIGIT both showed elevated expression levels in CD4+Foxp3+cells in RA patients and they were not associated with disease activity of RA patients. CONCLUSION: Taken together, our findings indicate that CD4+CD25hiCD127low/-Foxp3+Helios+ may represent the real Treg cell population in patients with RA.