RESUMO
When helper T (TH) cell polarization was initially described three decades ago, the TH cell universe grew dramatically. New subsets were described based on their expression of few specific cytokines. Beyond TH1 and TH2 cells, this led to the coining of various TH17 and regulatory (Treg) cell subsets as well as TH22, TH25, follicular helper (TFH), TH3, TH5 and TH9 cells. High-dimensional single-cell analysis revealed that a categorization of TH cells into a single-cytokine-based nomenclature fails to capture the complexity and diversity of TH cells. Similar to the simple nomenclature used to describe innate lymphoid cells (ILCs), we propose that TH cell polarization should be categorized in terms of the help they provide to phagocytes (type 1), to B cells, eosinophils and mast cells (type 2) and to non-immune tissue cells, including the stroma and epithelium (type 3). Studying TH cells based on their helper function and the cells they help, rather than phenotypic features such as individual analyzed cytokines or transcription factors, better captures TH cell plasticity and conversion as well as the breadth of immune responses in vivo.
Assuntos
Citocinas/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Linfócitos B/imunologia , Plasticidade Celular/imunologia , Eosinófilos/imunologia , Epitélio/imunologia , Humanos , Imunidade Inata/imunologia , Linfócitos/imunologia , Fagócitos/imunologiaRESUMO
Immune cell trafficking constitutes a fundamental component of immunological response to tissue injury, but the contribution of intrinsic RNA nucleotide modifications to this response remains elusive. We report that RNA editor ADAR2 exerts a tissue- and stress-specific regulation of endothelial responses to interleukin-6 (IL-6), which tightly controls leukocyte trafficking in IL-6-inflamed and ischemic tissues. Genetic ablation of ADAR2 from vascular endothelial cells diminished myeloid cell rolling and adhesion on vascular walls and reduced immune cell infiltration within ischemic tissues. ADAR2 was required in the endothelium for the expression of the IL-6 receptor subunit, IL-6 signal transducer (IL6ST; gp130), and subsequently, for IL-6 trans-signaling responses. ADAR2-induced adenosine-to-inosine RNA editing suppressed the Drosha-dependent primary microRNA processing, thereby overwriting the default endothelial transcriptional program to safeguard gp130 expression. This work demonstrates a role for ADAR2 epitranscriptional activity as a checkpoint in IL-6 trans-signaling and immune cell trafficking to sites of tissue injury.
Assuntos
Interleucina-6 , RNA , Células Endoteliais/metabolismo , Receptor gp130 de Citocina , Endotélio/metabolismo , Adenosina Desaminase/genética , Adenosina Desaminase/metabolismoRESUMO
The cellular sources of interleukin 6 (IL-6) that are relevant for differentiation of the TH17 subset of helper T cells remain unclear. Here we used a novel strategy for the conditional deletion of distinct IL-6-producing cell types to show that dendritic cells (DCs) positive for the signaling regulator Sirpα were essential for the generation of pathogenic TH17 cells. Using their IL-6 receptor α-chain (IL-6Rα), Sirpα+ DCs trans-presented IL-6 to T cells during the process of cognate interaction. While ambient IL-6 was sufficient to suppress the induction of expression of the transcription factor Foxp3 in T cells, trans-presentation of IL-6 by DC-bound IL-6Rα (called 'IL-6 cluster signaling' here) was needed to prevent premature induction of interferon-γ (IFN-γ) expression in T cells and to generate pathogenic TH17 cells in vivo. Our findings should guide therapeutic approaches for the treatment of TH17-cell-mediated autoimmune diseases.
Assuntos
Sistema Nervoso Central/imunologia , Células Dendríticas/imunologia , Encefalomielite Autoimune Experimental/imunologia , Subunidade alfa de Receptor de Interleucina-6/genética , Interleucina-6/metabolismo , Células Th17/imunologia , Animais , Autoimunidade , Diferenciação Celular , Células Cultivadas , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Humanos , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Glicoproteína Mielina-Oligodendrócito/imunologia , Fragmentos de Peptídeos/imunologia , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismoRESUMO
Solitary intestinal lymphoid tissues such as cryptopatches (CPs) and isolated lymphoid follicles (ILFs) constitute steady-state activation hubs containing group 3 innate lymphoid cells (ILC3) that continuously produce interleukin (IL)-22. The outer surface of CPs and ILFs is demarcated by a poorly characterized population of CD11c+ cells. Using genome-wide single-cell transcriptional profiling of intestinal mononuclear phagocytes and multidimensional flow cytometry, we found that CP- and ILF-associated CD11c+ cells were a transcriptionally distinct subset of intestinal cDCs, which we term CIA-DCs. CIA-DCs required programming by CP- and ILF-resident CCR6+ ILC3 via lymphotoxin-ß receptor signaling in cDCs. CIA-DCs differentially expressed genes associated with immunoregulation and were the major cellular source of IL-22 binding protein (IL-22BP) at steady state. Mice lacking CIA-DC-derived IL-22BP exhibited diminished expression of epithelial lipid transporters, reduced lipid resorption, and changes in body fat homeostasis. Our findings provide insight into the design principles of an immunoregulatory checkpoint controlling nutrient absorption.
Assuntos
Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Imunidade Inata , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Nódulos Linfáticos Agregados/citologia , Nódulos Linfáticos Agregados/imunologia , Receptores de Interleucina/biossíntese , Animais , Biomarcadores , Expressão Gênica , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Imunofenotipagem , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Metabolismo dos Lipídeos , Camundongos , Camundongos Transgênicos , RNA Citoplasmático Pequeno/genética , Receptores de Interleucina/genética , Transdução de SinaisRESUMO
Pathogenic lymphocytes initiate the development of chronic inflammatory diseases. The cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) (encoded by Csf2) is a key communicator between pathogenic lymphocytes and tissue-invading inflammatory phagocytes. However, the molecular properties of GM-CSF-producing cells and the mode of Csf2 regulation in vivo remain unclear. To systematically study and manipulate GM-CSF+ cells and their progeny in vivo, we generated a fate-map and reporter of GM-CSF expression mouse strain (FROG). We mapped the phenotypic and functional profile of auto-aggressive T helper (Th) cells during neuroinflammation and identified the signature and pathogenic memory of a discrete encephalitogenic Th subset. These cells required interleukin-23 receptor (IL-23R) and IL-1R but not IL-6R signaling for their maintenance and pathogenicity. Specific ablation of this subset interrupted the inflammatory cascade, despite the unperturbed tissue accumulation of other Th subsets (e.g., Th1 and Th17), highlighting that GM-CSF expression not only marks pathogenic Th cells, but that this subset mediates immunopathology and tissue destruction.
Assuntos
Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Interleucina-1beta/imunologia , Subunidade p19 da Interleucina-23/imunologia , Células Th1/imunologia , Células Th17/imunologia , Animais , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Inflamação/genética , Inflamação/patologia , Interferon gama/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores CXCR6/metabolismo , Receptores de Interleucina/genética , Receptores de Interleucina/imunologia , Receptores Tipo I de Interleucina-1/genética , Receptores Tipo I de Interleucina-1/imunologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Chronic inflammation drives the progression of colorectal cancer (CRC). Increased expression of interleukin (IL)-17A is associated with poor prognosis, and IL-17A blockade curbs tumor progression in preclinical models of CRC. Here we examined the impact of IL-1 signaling, a key regulator of the IL-17 pathway, in different cell types within the CRC microenvironment. Genetic deletion of the IL-1 receptor (IL-1R1) in epithelial cells alleviated tumorigenesis in the APC model of CRC, demonstrating a cell-autonomous role for IL-1 signaling in early tumor seed outgrowth. T cell specific ablation of IL-1R1 decreased tumor-elicited inflammation dependent on IL-17 and IL-22, thereby reducing CRC progression. The pro-tumorigenic roles of IL-1 were counteracted by its effects on myeloid cells, particularly neutrophils, where IL-1R1 ablation resulted in bacterial invasion into tumors, heightened inflammation and aggressive CRC progression. Thus, IL-1 signaling elicits cell-type-specific responses, which, in aggregate, set the inflammatory tone of the tumor microenvironment and determine the propensity for disease progression.
Assuntos
Neoplasias Colorretais/imunologia , Inflamação/metabolismo , Interleucina-17/metabolismo , Interleucina-1/metabolismo , Neutrófilos/imunologia , Salmonelose Animal/imunologia , Salmonella/imunologia , Animais , Carcinogênese , Células Cultivadas , Humanos , Interleucina-1/genética , Interleucina-1/imunologia , Interleucinas/metabolismo , Camundongos , Camundongos Knockout , Neutrófilos/ultraestrutura , Especificidade de Órgãos , Receptores de Interleucina-1/genética , Transdução de Sinais , Microambiente Tumoral , Interleucina 22RESUMO
The modification of proteins by ubiquitin has a major role in cells of the immune system and is counteracted by various deubiquitinating enzymes (DUBs) with poorly defined functions. Here we identified the ubiquitin-specific protease USP8 as a regulatory component of the T cell antigen receptor (TCR) signalosome that interacted with the adaptor Gads and the regulatory molecule 14-3-3ß. Caspase-dependent processing of USP8 occurred after stimulation of the TCR. T cell-specific deletion of USP8 in mice revealed that USP8 was essential for thymocyte maturation and upregulation of the gene encoding the cytokine receptor IL-7Rα mediated by the transcription factor Foxo1. Mice with T cell-specific USP8 deficiency developed colitis that was promoted by disturbed T cell homeostasis, a predominance of CD8(+) γδ T cells in the intestine and impaired regulatory T cell function. Collectively, our data reveal an unexpected role for USP8 as an immunomodulatory DUB in T cells.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Endopeptidases/imunologia , Complexos Endossomais de Distribuição Requeridos para Transporte/imunologia , Timócitos/imunologia , Ubiquitina Tiolesterase/imunologia , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/genética , Colite/genética , Colite/imunologia , Endopeptidases/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead/imunologia , Fatores de Transcrição Forkhead/metabolismo , Homeostase , Humanos , Células Jurkat , Camundongos , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Interleucina-7/imunologia , Receptores de Interleucina-7/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Timócitos/metabolismo , Ubiquitina Tiolesterase/genéticaRESUMO
The quality of the adaptive immune response depends on the differentiation of distinct CD4(+) helper T cell subsets, and the magnitude of an immune response is controlled by CD4(+)Foxp3(+) regulatory T cells (Treg cells). However, how a tissue- and cell type-specific suppressor program of Treg cells is mechanistically orchestrated has remained largely unexplored. Through the use of Treg cell-specific gene targeting, we found that the suppression of allergic immune responses in the lungs mediated by T helper type 2 (TH2) cells was dependent on the activity of the protein kinase CK2. Genetic ablation of the ß-subunit of CK2 specifically in Treg cells resulted in the proliferation of a hitherto-unexplored ILT3(+) Treg cell subpopulation that was unable to control the maturation of IRF4(+)PD-L2(+) dendritic cells required for the development of TH2 responses in vivo.
Assuntos
Caseína Quinase II/imunologia , Linfócitos T Reguladores/imunologia , Células Th2/imunologia , Animais , Linfócitos T CD4-Positivos/enzimologia , Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular/imunologia , Processos de Crescimento Celular/imunologia , Linhagem Celular , Células Dendríticas/enzimologia , Células Dendríticas/imunologia , Fatores de Transcrição Forkhead/imunologia , Humanos , Hipersensibilidade/sangue , Hipersensibilidade/imunologia , Fatores Reguladores de Interferon/imunologia , Leucócitos Mononucleares/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores de Superfície Celular/imunologia , Linfócitos T Reguladores/enzimologia , Células Th2/enzimologiaRESUMO
Pro-inflammatory T cells in the central nervous system (CNS) are causally associated with multiple demyelinating and neurodegenerative diseases1-6, but the pathways that control these responses remain unclear. Here we define a population of inflammatory group 3 innate lymphoid cells (ILC3s) that infiltrate the CNS in a mouse model of multiple sclerosis. These ILC3s are derived from the circulation, localize in proximity to infiltrating T cells in the CNS, function as antigen-presenting cells that restimulate myelin-specific T cells, and are increased in individuals with multiple sclerosis. Notably, antigen presentation by inflammatory ILC3s is required to promote T cell responses in the CNS and the development of multiple-sclerosis-like disease in mouse models. By contrast, conventional and tissue-resident ILC3s in the periphery do not appear to contribute to disease induction, but instead limit autoimmune T cell responses and prevent multiple-sclerosis-like disease when experimentally targeted to present myelin antigen. Collectively, our data define a population of inflammatory ILC3s that is essential for directly promoting T-cell-dependent neuroinflammation in the CNS and reveal the potential of harnessing peripheral tissue-resident ILC3s for the prevention of autoimmune disease.
Assuntos
Encefalomielite Autoimune Experimental , Esclerose Múltipla , Animais , Células Apresentadoras de Antígenos , Antígenos/metabolismo , Imunidade Inata , Linfócitos , Camundongos , Doenças Neuroinflamatórias , Esclerose/metabolismoRESUMO
The molecular checkpoints that drive inflammatory bowel diseases are incompletely understood. Here we found more T cells expressing the transcription factor PU.1 and interleukin 9 (IL-9) in patients with ulcerative colitis. In an animal model, citrine reporter mice had more IL-9-expressing mucosal T cells in experimental oxazolone-induced colitis. IL-9 deficiency suppressed acute and chronic colitis. Mice with PU.1 deficiency in T cells were protected from colitis, whereas treatment with antibody to IL-9 suppressed colitis. Functionally, IL-9 impaired intestinal barrier function and prevented mucosal wound healing in vivo. Thus, our findings suggest that the TH9 subset of helper T cells serves an important role in driving ulcerative colitis by regulating intestinal epithelial cells and that TH9 cells represent a likely target for the treatment of chronic intestinal inflammation.
Assuntos
Colite/etiologia , Mucosa Intestinal/imunologia , Proteínas Proto-Oncogênicas/fisiologia , Receptores de Interleucina-9/fisiologia , Transdução de Sinais/fisiologia , Subpopulações de Linfócitos T/fisiologia , Linfócitos T Auxiliares-Indutores/imunologia , Transativadores/fisiologia , Animais , Claudina-2/genética , Colite/imunologia , Colite Ulcerativa/imunologia , Humanos , Interleucina-9/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Células Th2/imunologia , CicatrizaçãoRESUMO
In this issue of Immunity, Takata et al. (2017) describe a novel method to differentiate macrophages from iPSCs. These cells, which they call iMacs, are similar to yolk-sac-derived macrophages and are capable of undergoing terminal differentiation into tissue-resident-like macrophages in vitro and in vivo.
Assuntos
Diferenciação Celular , Macrófagos/citologia , Feto/citologia , Humanos , Saco Vitelino/citologiaRESUMO
Lymph nodes (LNs) are strategically situated throughout the body at junctures of the blood vascular and lymphatic systems to direct immune responses against antigens draining from peripheral tissues. The current paradigm describes LN development as a programmed process that is governed through the interaction between mesenchymal lymphoid tissue organizer (LTo) cells and hematopoietic lymphoid tissue inducer (LTi) cells. Using cell-type-specific ablation of key molecules involved in lymphoid organogenesis, we found that initiation of LN development is dependent on LTi-cell-mediated activation of lymphatic endothelial cells (LECs) and that engagement of mesenchymal stromal cells is a succeeding event. LEC activation was mediated mainly by signaling through receptor activator of NF-κB (RANK) and the non-canonical NF-κB pathway and was steered by sphingosine-1-phosphate-receptor-dependent retention of LTi cells in the LN anlage. Finally, the finding that pharmacologically enforced interaction between LTi cells and LECs promotes ectopic LN formation underscores the central LTo function of LECs.
Assuntos
Células Endoteliais/fisiologia , Linfonodos/fisiologia , Células-Tronco Mesenquimais/fisiologia , Organogênese , Animais , Diferenciação Celular , Células Cultivadas , Coristoma , Embrião de Mamíferos , Receptor beta de Linfotoxina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , NF-kappa B/metabolismo , Receptor Ativador de Fator Nuclear kappa-B/metabolismo , Receptores de Lisoesfingolipídeo/metabolismo , Transdução de SinaisRESUMO
A subset of children with autism spectrum disorder appear to show an improvement in their behavioural symptoms during the course of a fever, a sign of systemic inflammation1,2. Here we elucidate the molecular and neural mechanisms that underlie the beneficial effects of inflammation on social behaviour deficits in mice. We compared an environmental model of neurodevelopmental disorders in which mice were exposed to maternal immune activation (MIA) during embryogenesis3,4 with mouse models that are genetically deficient for contactin-associated protein-like 2 (Cntnap2)5, fragile X mental retardation-1 (Fmr1)6 or Sh3 and multiple ankyrin repeat domains 3 (Shank3)7. We establish that the social behaviour deficits in offspring exposed to MIA can be temporarily rescued by the inflammatory response elicited by the administration of lipopolysaccharide (LPS). This behavioural rescue was accompanied by a reduction in neuronal activity in the primary somatosensory cortex dysgranular zone (S1DZ), the hyperactivity of which was previously implicated in the manifestation of behavioural phenotypes associated with offspring exposed to MIA8. By contrast, we did not observe an LPS-induced rescue of social deficits in the monogenic models. We demonstrate that the differences in responsiveness to the LPS treatment between the MIA and the monogenic models emerge from differences in the levels of cytokine production. LPS treatment in monogenic mutant mice did not induce amounts of interleukin-17a (IL-17a) comparable to those induced in MIA offspring; bypassing this difference by directly delivering IL-17a into S1DZ was sufficient to promote sociability in monogenic mutant mice as well as in MIA offspring. Conversely, abrogating the expression of IL-17 receptor subunit a (IL-17Ra) in the neurons of the S1DZ eliminated the ability of LPS to reverse the sociability phenotypes in MIA offspring. Our data support a neuroimmune mechanism that underlies neurodevelopmental disorders in which the production of IL-17a during inflammation can ameliorate the expression of social behaviour deficits by directly affecting neuronal activity in the central nervous system.
Assuntos
Interleucina-17/imunologia , Transtornos do Neurodesenvolvimento/imunologia , Animais , Comportamento Animal , Modelos Animais de Doenças , Feminino , Proteína do X Frágil da Deficiência Intelectual , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Comportamento SocialRESUMO
Externalized histones erupt from the nucleus as extracellular traps, are associated with several acute and chronic lung disorders, but their implications in the molecular pathogenesis of interstitial lung disease are incompletely defined. To investigate the role and molecular mechanisms of externalized histones within the immunologic networks of pulmonary fibrosis, we studied externalized histones in human and animal bronchoalveolar lavage (BAL) samples of lung fibrosis. Neutralizing anti-histone antibodies were administered in bleomycin-induced fibrosis of C57BL/6 J mice, and subsequent studies used conditional/constitutive knockout mouse strains for TGFß and IL-27 signaling along with isolated platelets and cultured macrophages. We found that externalized histones (citH3) were significantly (P < 0.01) increased in cell-free BAL fluids of patients with idiopathic pulmonary fibrosis (IPF; n = 29) as compared to healthy controls (n = 10). The pulmonary sources of externalized histones were Ly6G+CD11b+ neutrophils and nonhematopoietic cells after bleomycin in mice. Neutralizing monoclonal anti-histone H2A/H4 antibodies reduced the pulmonary collagen accumulation and hydroxyproline concentration. Histones activated platelets to release TGFß1, which signaled through the TGFbRI/TGFbRII receptor complex on LysM+ cells to antagonize macrophage-derived IL-27 production. TGFß1 evoked multiple downstream mechanisms in macrophages, including p38 MAPK, tristetraprolin, IL-10, and binding of SMAD3 to the IL-27 promotor regions. IL-27RA-deficient mice displayed more severe collagen depositions suggesting that intact IL-27 signaling limits fibrosis. In conclusion, externalized histones inactivate a safety switch of antifibrotic, macrophage-derived IL-27 by boosting platelet-derived TGFß1. Externalized histones are accessible to neutralizing antibodies for improving the severity of experimental pulmonary fibrosis.
Assuntos
Fibrose Pulmonar Idiopática , Interleucina-27 , Humanos , Camundongos , Animais , Camundongos Endogâmicos C57BL , Histonas , Plaquetas , Fibrose Pulmonar Idiopática/induzido quimicamente , Fibrose Pulmonar Idiopática/genéticaRESUMO
An Amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
During early embryogenesis, microglia arise from yolk sac progenitors that populate the developing central nervous system (CNS), but how the tissue-resident macrophages are maintained throughout the organism's lifespan still remains unclear. Here, we describe a system that allows specific, conditional ablation of microglia in adult mice. We found that the microglial compartment was reconstituted within 1 week of depletion. Microglia repopulation relied on CNS-resident cells, independent from bone-marrow-derived precursors. During repopulation, microglia formed clusters of highly proliferative cells that migrated apart once steady state was achieved. Proliferating microglia expressed high amounts of the interleukin-1 receptor (IL-1R), and treatment with an IL-1R antagonist during the repopulation phase impaired microglia proliferation. Hence, microglia have the potential for efficient self-renewal without the contribution of peripheral myeloid cells, and IL-1R signaling participates in this restorative proliferation process.
Assuntos
Células-Tronco Hematopoéticas/citologia , Macrófagos/citologia , Microglia/citologia , Receptores Tipo I de Interleucina-1/biossíntese , Animais , Sequência de Bases , Células da Medula Óssea/imunologia , Receptor 1 de Quimiocina CX3C , Diferenciação Celular , Movimento Celular , Proliferação de Células , Sistema Nervoso Central/citologia , Interleucina-1beta/biossíntese , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Quimiocinas/genética , Receptores Tipo I de Interleucina-1/antagonistas & inibidores , Análise de Sequência de DNA , Transdução de Sinais , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/genéticaRESUMO
The formation of red blood cells begins with the differentiation of multipotent haematopoietic progenitors. Reconstructing the steps of this differentiation represents a general challenge in stem-cell biology. Here we used single-cell transcriptomics, fate assays and a theory that allows the prediction of cell fates from population snapshots to demonstrate that mouse haematopoietic progenitors differentiate through a continuous, hierarchical structure into seven blood lineages. We uncovered coupling between the erythroid and the basophil or mast cell fates, a global haematopoietic response to erythroid stress and novel growth factor receptors that regulate erythropoiesis. We defined a flow cytometry sorting strategy to purify early stages of erythroid differentiation, completely isolating classically defined burst-forming and colony-forming progenitors. We also found that the cell cycle is progressively remodelled during erythroid development and during a sharp transcriptional switch that ends the colony-forming progenitor stage and activates terminal differentiation. Our work showcases the utility of linking transcriptomic data to predictive fate models, and provides insights into lineage development in vivo.
Assuntos
Eritrócitos/citologia , Células Precursoras Eritroides/citologia , Eritropoese , Animais , Basófilos/citologia , Ciclo Celular/genética , Ciclo Celular/fisiologia , Linhagem da Célula/efeitos dos fármacos , Linhagem da Célula/genética , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Células Precursoras Eritroides/efeitos dos fármacos , Células Precursoras Eritroides/metabolismo , Eritropoese/efeitos dos fármacos , Feminino , Citometria de Fluxo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Mastócitos/citologia , Camundongos , Proteínas Proto-Oncogênicas c-kit/metabolismo , RNA Citoplasmático Pequeno/análise , RNA Citoplasmático Pequeno/genética , Análise de Célula Única , TranscriptomaRESUMO
Genetic regulators and environmental stimuli modulate T cell activation in autoimmunity and cancer. The enzyme co-factor tetrahydrobiopterin (BH4) is involved in the production of monoamine neurotransmitters, the generation of nitric oxide, and pain1,2. Here we uncover a link between these processes, identifying a fundamental role for BH4 in T cell biology. We find that genetic inactivation of GTP cyclohydrolase 1 (GCH1, the rate-limiting enzyme in the synthesis of BH4) and inhibition of sepiapterin reductase (the terminal enzyme in the synthetic pathway for BH4) severely impair the proliferation of mature mouse and human T cells. BH4 production in activated T cells is linked to alterations in iron metabolism and mitochondrial bioenergetics. In vivo blockade of BH4 synthesis abrogates T-cell-mediated autoimmunity and allergic inflammation, and enhancing BH4 levels through GCH1 overexpression augments responses by CD4- and CD8-expressing T cells, increasing their antitumour activity in vivo. Administration of BH4 to mice markedly reduces tumour growth and expands the population of intratumoral effector T cells. Kynurenine-a tryptophan metabolite that blocks antitumour immunity-inhibits T cell proliferation in a manner that can be rescued by BH4. Finally, we report the development of a potent SPR antagonist for possible clinical use. Our data uncover GCH1, SPR and their downstream metabolite BH4 as critical regulators of T cell biology that can be readily manipulated to either block autoimmunity or enhance anticancer immunity.
Assuntos
Doenças Autoimunes/imunologia , Biopterinas/análogos & derivados , Neoplasias/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Administração Oral , Oxirredutases do Álcool/antagonistas & inibidores , Oxirredutases do Álcool/metabolismo , Animais , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/patologia , Biopterinas/biossíntese , Biopterinas/metabolismo , Biopterinas/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Coenzimas/metabolismo , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Feminino , GTP Cicloidrolase/genética , GTP Cicloidrolase/metabolismo , Humanos , Hipersensibilidade/imunologia , Ferro/metabolismo , Cinurenina/metabolismo , Cinurenina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismoRESUMO
B-1 cells have intricate biology, with distinct function, phenotype and developmental origin from conventional B cells. They generate a B cell receptor with conserved germline characteristics and biased V(D)J recombination, allowing this innate-like lymphocyte to spontaneously produce self-reactive natural antibodies (NAbs) and become activated by immune stimuli in a T cell-independent manner. NAbs were suggested as "rheostats" for the chronic diseases in advanced age. In fact, age-dependent loss of function of NAbs has been associated with clinically-relevant diseases in the elderly, such as atherosclerosis and neurodegenerative disorders. Here, we analyzed comprehensively the ontogeny, phenotypic characteristics, functional properties and emerging roles of B-1 cells and NAbs in health and disease. Additionally, after navigating through the complexities of B-1 cell biology from development to aging, therapeutic opportunities in the field are discussed.