RESUMO
Myeloid cells are a major cellular compartment of the immune system comprising monocytes, dendritic cells, tissue macrophages, and granulocytes. Models of cellular ontogeny, activation, differentiation, and tissue-specific functions of myeloid cells have been revisited during the last years with surprising results; for example, most tissue macrophages are yolk sac derived, monocytes and macrophages follow a multidimensional model of activation, and tissue signals have a significant impact on the functionality of all these cells. While these exciting results have brought these cells back to center stage, their enormous plasticity and heterogeneity, during both homeostasis and disease, are far from understood. At the same time, the ongoing revolution in single-cell genomics, with single-cell RNA sequencing (scRNA-seq) leading the way, promises to change this. Prevailing models of hematopoiesis with distinct intermediates are challenged by scRNA-seq data suggesting more continuous developmental trajectories in the myeloid cell compartment. Cell subset structures previously defined by protein marker expression need to be revised based on unbiased analyses of scRNA-seq data. Particularly in inflammatory conditions, myeloid cells exhibit substantially vaster heterogeneity than previously anticipated, and work performed within large international projects, such as the Human Cell Atlas, has already revealed novel tissue macrophage subsets. Based on these exciting developments, we propose the next steps to a full understanding of the myeloid cell compartment in health and diseases.
Assuntos
Diferenciação Celular , Microambiente Celular , Inflamação/imunologia , Células Mieloides/fisiologia , Animais , Biomarcadores , Plasticidade Celular , Homeostase , Humanos , Análise de Sequência de RNARESUMO
The medical burden of stroke extends beyond the brain injury itself and is largely determined by chronic comorbidities that develop secondarily. We hypothesized that these comorbidities might share a common immunological cause, yet chronic effects post-stroke on systemic immunity are underexplored. Here, we identify myeloid innate immune memory as a cause of remote organ dysfunction after stroke. Single-cell sequencing revealed persistent pro-inflammatory changes in monocytes/macrophages in multiple organs up to 3 months after brain injury, notably in the heart, leading to cardiac fibrosis and dysfunction in both mice and stroke patients. IL-1ß was identified as a key driver of epigenetic changes in innate immune memory. These changes could be transplanted to naive mice, inducing cardiac dysfunction. By neutralizing post-stroke IL-1ß or blocking pro-inflammatory monocyte trafficking with a CCR2/5 inhibitor, we prevented post-stroke cardiac dysfunction. Such immune-targeted therapies could potentially prevent various IL-1ß-mediated comorbidities, offering a framework for secondary prevention immunotherapy.
Assuntos
Lesões Encefálicas , Imunidade Inata , Memória Imunológica , Inflamação , Interleucina-1beta , Camundongos Endogâmicos C57BL , Monócitos , Animais , Camundongos , Interleucina-1beta/metabolismo , Lesões Encefálicas/imunologia , Humanos , Masculino , Monócitos/metabolismo , Monócitos/imunologia , Inflamação/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/imunologia , Cardiopatias/imunologia , Feminino , Receptores CCR2/metabolismo , Fibrose , Epigênese Genética , Imunidade TreinadaRESUMO
Despite advances in defining diverse somatic mutations that cause myeloid malignancies, a significant heritable component for these cancers remains largely unexplained. Here, we perform rare variant association studies in a large population cohort to identify inherited predisposition genes for these blood cancers. CTR9, which encodes a key component of the PAF1 transcription elongation complex, is among the significant genes identified. The risk variants found in the cases cause loss of function and result in a â¼10-fold increased odds of acquiring a myeloid malignancy. Partial CTR9 loss of function expands human hematopoietic stem cells (HSCs) by increased super elongation complex-mediated transcriptional activity, which thereby increases the expression of key regulators of HSC self-renewal. By following up on insights from a human genetic study examining inherited predisposition to the myeloid malignancies, we define a previously unknown antagonistic interaction between the PAF1 and super elongation complexes. These insights could enable targeted approaches for blood cancer prevention.
Assuntos
Neoplasias Hematológicas , Fosfoproteínas , Elongação da Transcrição Genética , Fatores de Transcrição , Humanos , Neoplasias Hematológicas/genética , Células-Tronco Hematopoéticas/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/genética , Fosfoproteínas/genéticaRESUMO
Hematopoietic stem cells (HSCs) and downstream progenitors have long been studied based on phenotype, cell purification, proliferation, and transplantation into myeloablated recipients. These experiments, complemented by data on expression profiles, mouse mutants, and humans with hematopoietic defects, are the foundation for the current hematopoietic differentiation tree. However, there are fundamental gaps in our knowledge of the quantitative and qualitative operation of the HSC/progenitor system under physiological and pathological conditions in vivo. The hallmarks of HSCs, self-renewal and multipotency, are observed in in vitro assays and cell transplantation experiments; however, the extent to which these features occur naturally in HSCs and progenitors remains uncertain. We focus here on work that strives to address these unresolved questions, with emphasis on fate mapping and modeling of the hematopoietic flow from stem cells toward myeloid and lymphoid lineages during development and adult life.
Assuntos
Envelhecimento/imunologia , Diferenciação Celular , Hematopoese , Células-Tronco Hematopoéticas/fisiologia , Células Progenitoras Linfoides/fisiologia , Animais , Linhagem da Célula , Autorrenovação Celular , Humanos , Camundongos , Modelos Teóricos , TranscriptomaRESUMO
Neutrophils are abundant immune cells in the circulation and frequently infiltrate tumors in substantial numbers. However, their precise functions in different cancer types remain incompletely understood, including in the brain microenvironment. We therefore investigated neutrophils in tumor tissue of glioma and brain metastasis patients, with matched peripheral blood, and herein describe the first in-depth analysis of neutrophil phenotypes and functions in these tissues. Orthogonal profiling strategies in humans and mice revealed that brain tumor-associated neutrophils (TANs) differ significantly from blood neutrophils and have a prolonged lifespan and immune-suppressive and pro-angiogenic capacity. TANs exhibit a distinct inflammatory signature, driven by a combination of soluble inflammatory mediators including tumor necrosis factor alpha (TNF-É) and Ceruloplasmin, which is more pronounced in TANs from brain metastasis versus glioma. Myeloid cells, including tumor-associated macrophages, emerge at the core of this network of pro-inflammatory mediators, supporting the concept of a critical myeloid niche regulating overall immune suppression in human brain tumors.
RESUMO
Adult mammalian skin wounds heal by forming fibrotic scars. We report that full-thickness injuries of reindeer antler skin (velvet) regenerate, whereas back skin forms fibrotic scar. Single-cell multi-omics reveal that uninjured velvet fibroblasts resemble human fetal fibroblasts, whereas back skin fibroblasts express inflammatory mediators mimicking pro-fibrotic adult human and rodent fibroblasts. Consequently, injury elicits site-specific immune responses: back skin fibroblasts amplify myeloid infiltration and maturation during repair, whereas velvet fibroblasts adopt an immunosuppressive phenotype that restricts leukocyte recruitment and hastens immune resolution. Ectopic transplantation of velvet to scar-forming back skin is initially regenerative, but progressively transitions to a fibrotic phenotype akin to the scarless fetal-to-scar-forming transition reported in humans. Skin regeneration is diminished by intensifying, or enhanced by neutralizing, these pathologic fibroblast-immune interactions. Reindeer represent a powerful comparative model for interrogating divergent wound healing outcomes, and our results nominate decoupling of fibroblast-immune interactions as a promising approach to mitigate scar.
Assuntos
Rena , Cicatrização , Adulto , Animais , Humanos , Cicatriz/patologia , Fibroblastos/patologia , Transplante de Pele , Pele/patologia , Feto/patologiaRESUMO
Tumor-infiltrating myeloid cells (TIMs) are key regulators in tumor progression, but the similarity and distinction of their fundamental properties across different tumors remain elusive. Here, by performing a pan-cancer analysis of single myeloid cells from 210 patients across 15 human cancer types, we identified distinct features of TIMs across cancer types. Mast cells in nasopharyngeal cancer were found to be associated with better prognosis and exhibited an anti-tumor phenotype with a high ratio of TNF+/VEGFA+ cells. Systematic comparison between cDC1- and cDC2-derived LAMP3+ cDCs revealed their differences in transcription factors and external stimulus. Additionally, pro-angiogenic tumor-associated macrophages (TAMs) were characterized with diverse markers across different cancer types, and the composition of TIMs appeared to be associated with certain features of somatic mutations and gene expressions. Our results provide a systematic view of the highly heterogeneous TIMs and suggest future avenues for rational, targeted immunotherapies.
Assuntos
Células Mieloides/patologia , Neoplasias/genética , Neoplasias/patologia , Análise de Célula Única , Transcrição Gênica , Linhagem Celular Tumoral , Linhagem da Célula , Células Dendríticas/metabolismo , Feminino , Humanos , Proteínas de Membrana Lisossomal/metabolismo , Macrófagos/metabolismo , Masculino , Mastócitos/patologia , Monócitos/metabolismo , Proteínas de Neoplasias/metabolismo , Transcriptoma/genéticaRESUMO
Cytomegaloviruses (CMVs) have co-evolved with their mammalian hosts for millions of years, leading to remarkable host specificity and high infection prevalence. Macrophages, which already populate barrier tissues in the embryo, are the predominant immune cells at potential CMV entry sites. Here we show that, upon CMV infection, macrophages undergo a morphological, immunophenotypic, and metabolic transformation process with features of stemness, altered migration, enhanced invasiveness, and provision of the cell cycle machinery for viral proliferation. This complex process depends on Wnt signaling and the transcription factor ZEB1. In pulmonary infection, mouse CMV primarily targets and reprograms alveolar macrophages, which alters lung physiology and facilitates primary CMV and secondary bacterial infection by attenuating the inflammatory response. Thus, CMV profoundly perturbs macrophage identity beyond established limits of plasticity and rewires specific differentiation processes, allowing viral spread and impairing innate tissue immunity.
Assuntos
Citomegalovirus/fisiologia , Macrófagos Alveolares/virologia , Animais , Apresentação de Antígeno , Efeito Espectador , Ciclo Celular , Linhagem Celular Transformada , Reprogramação Celular , Citomegalovirus/patogenicidade , Citomegalovirus/ultraestrutura , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/virologia , Proteínas de Fluorescência Verde/metabolismo , Pulmão/patologia , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/ultraestrutura , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Fenótipo , Células-Tronco/patologia , Replicação Viral/fisiologia , Via de Sinalização WntRESUMO
Metastasis is the leading cause of cancer-related deaths, and greater knowledge of the metastatic microenvironment is necessary to effectively target this process. Microenvironmental changes occur at distant sites prior to clinically detectable metastatic disease; however, the key niche regulatory signals during metastatic progression remain poorly characterized. Here, we identify a core immune suppression gene signature in pre-metastatic niche formation that is expressed predominantly by myeloid cells. We target this immune suppression program by utilizing genetically engineered myeloid cells (GEMys) to deliver IL-12 to modulate the metastatic microenvironment. Our data demonstrate that IL12-GEMy treatment reverses immune suppression in the pre-metastatic niche by activating antigen presentation and T cell activation, resulting in reduced metastatic and primary tumor burden and improved survival of tumor-bearing mice. We demonstrate that IL12-GEMys can functionally modulate the core program of immune suppression in the pre-metastatic niche to successfully rebalance the dysregulated metastatic microenvironment in cancer.
Assuntos
Terapia de Imunossupressão , Células Mieloides/metabolismo , Imunidade Adaptativa , Animais , Linhagem Celular Tumoral , Engenharia Genética , Humanos , Interleucina-12/genética , Interleucina-12/metabolismo , Pulmão/metabolismo , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células Mieloides/citologia , Células Mieloides/imunologia , Metástase Neoplásica , Rabdomiossarcoma/metabolismo , Rabdomiossarcoma/patologia , Taxa de Sobrevida , Linfócitos T/imunologia , Linfócitos T/metabolismo , Microambiente TumoralRESUMO
Single-cell RNA sequencing (scRNA-seq) is a powerful tool for defining cellular diversity in tumors, but its application toward dissecting mechanisms underlying immune-modulating therapies is scarce. We performed scRNA-seq analyses on immune and stromal populations from colorectal cancer patients, identifying specific macrophage and conventional dendritic cell (cDC) subsets as key mediators of cellular cross-talk in the tumor microenvironment. Defining comparable myeloid populations in mouse tumors enabled characterization of their response to myeloid-targeted immunotherapy. Treatment with anti-CSF1R preferentially depleted macrophages with an inflammatory signature but spared macrophage populations that in mouse and human expresses pro-angiogenic/tumorigenic genes. Treatment with a CD40 agonist antibody preferentially activated a cDC population and increased Bhlhe40+ Th1-like cells and CD8+ memory T cells. Our comprehensive analysis of key myeloid subsets in human and mouse identifies critical cellular interactions regulating tumor immunity and defines mechanisms underlying myeloid-targeted immunotherapies currently undergoing clinical testing.
Assuntos
Neoplasias do Colo/patologia , Células Mieloides/metabolismo , Análise de Célula Única/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Sequência de Bases/genética , Linfócitos T CD8-Positivos/imunologia , China , Neoplasias do Colo/terapia , Neoplasias Colorretais/patologia , Células Dendríticas/imunologia , Feminino , Humanos , Imunoterapia , Macrófagos/imunologia , Masculino , Camundongos , Pessoa de Meia-Idade , Análise de Sequência de RNA/métodos , Microambiente Tumoral/genética , Microambiente Tumoral/imunologiaRESUMO
Trained immunity, a functional state of myeloid cells, has been proposed as a compelling immune-oncological target. Its efficient induction requires direct engagement of myeloid progenitors in the bone marrow. For this purpose, we developed a bone marrow-avid nanobiologic platform designed specifically to induce trained immunity. We established the potent anti-tumor capabilities of our lead candidate MTP10-HDL in a B16F10 mouse melanoma model. These anti-tumor effects result from trained immunity-induced myelopoiesis caused by epigenetic rewiring of multipotent progenitors in the bone marrow, which overcomes the immunosuppressive tumor microenvironment. Furthermore, MTP10-HDL nanotherapy potentiates checkpoint inhibition in this melanoma model refractory to anti-PD-1 and anti-CTLA-4 therapy. Finally, we determined MTP10-HDL's favorable biodistribution and safety profile in non-human primates. In conclusion, we show that rationally designed nanobiologics can promote trained immunity and elicit a durable anti-tumor response either as a monotherapy or in combination with checkpoint inhibitor drugs.
Assuntos
Inibidores de Checkpoint Imunológico/uso terapêutico , Imunidade , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/patologia , Nanotecnologia , Acetilmuramil-Alanil-Isoglutamina/metabolismo , Animais , Comportamento Animal , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Proliferação de Células/efeitos dos fármacos , Colesterol/metabolismo , Feminino , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Inibidores de Checkpoint Imunológico/farmacologia , Imunidade/efeitos dos fármacos , Imunoterapia , Lipoproteínas HDL/metabolismo , Camundongos Endogâmicos C57BL , Primatas , Distribuição Tecidual/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacosRESUMO
Cell function and activity are regulated through integration of signaling, epigenetic, transcriptional, and metabolic pathways. Here, we introduce INs-seq, an integrated technology for massively parallel recording of single-cell RNA sequencing (scRNA-seq) and intracellular protein activity. We demonstrate the broad utility of INs-seq for discovering new immune subsets by profiling different intracellular signatures of immune signaling, transcription factor combinations, and metabolic activity. Comprehensive mapping of Arginase 1-expressing cells within tumor models, a metabolic immune signature of suppressive activity, discovers novel Arg1+ Trem2+ regulatory myeloid (Mreg) cells and identifies markers, metabolic activity, and pathways associated with these cells. Genetic ablation of Trem2 in mice inhibits accumulation of intra-tumoral Mreg cells, leading to a marked decrease in dysfunctional CD8+ T cells and reduced tumor growth. This study establishes INs-seq as a broadly applicable technology for elucidating integrated transcriptional and intra-cellular maps and identifies the molecular signature of myeloid suppressive cells in tumors.
Assuntos
Glicoproteínas de Membrana/metabolismo , Neoplasias/patologia , RNA Citoplasmático Pequeno/química , Receptores Imunológicos/metabolismo , Animais , Arginase/genética , Arginase/metabolismo , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/metabolismo , Lipopolissacarídeos/farmacologia , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/imunologia , Neoplasias/metabolismo , RNA Citoplasmático Pequeno/metabolismo , Receptores Imunológicos/genética , Análise de Sequência de RNA , Análise de Célula Única , Fatores de Transcrição/metabolismo , Microambiente Tumoral , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Quinases p38 Ativadas por MitógenoRESUMO
Brain metastasis (br-met) develops in an immunologically unique br-met niche. Central nervous system-native myeloid cells (CNS-myeloids) and bone-marrow-derived myeloid cells (BMDMs) cooperatively regulate brain immunity. The phenotypic heterogeneity and specific roles of these myeloid subsets in shaping the br-met niche to regulate br-met outgrowth have not been fully revealed. Applying multimodal single-cell analyses, we elucidated a heterogeneous but spatially defined CNS-myeloid response during br-met outgrowth. We found Ccr2+ BMDMs minimally influenced br-met while CNS-myeloid promoted br-met outgrowth. Additionally, br-met-associated CNS-myeloid exhibited downregulation of Cx3cr1. Cx3cr1 knockout in CNS-myeloid increased br-met incidence, leading to an enriched interferon response signature and Cxcl10 upregulation. Significantly, neutralization of Cxcl10 reduced br-met, while rCxcl10 increased br-met and recruited VISTAHi PD-L1+ CNS-myeloid to br-met lesions. Inhibiting VISTA- and PD-L1-signaling relieved immune suppression and reduced br-met burden. Our results demonstrate that loss of Cx3cr1 in CNS-myeloid triggers a Cxcl10-mediated vicious cycle, cultivating a br-met-promoting, immune-suppressive niche.
Assuntos
Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/secundário , Quimiocina CXCL10/metabolismo , Terapia de Imunossupressão , Células Mieloides/metabolismo , Animais , Células da Medula Óssea/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Receptor 1 de Quimiocina CX3C/metabolismo , Sistema Nervoso Central/patologia , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Interferons/metabolismo , Macrófagos/metabolismo , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Testes de Neutralização , Fenótipo , Linfócitos T/imunologia , Transcriptoma/genéticaRESUMO
Lineage tracing provides key insights into the fate of individual cells in complex organisms. Although effective genetic labeling approaches are available in model systems, in humans, most approaches require detection of nuclear somatic mutations, which have high error rates, limited scale, and do not capture cell state information. Here, we show that somatic mutations in mtDNA can be tracked by single-cell RNA or assay for transposase accessible chromatin (ATAC) sequencing. We leverage somatic mtDNA mutations as natural genetic barcodes and demonstrate their utility as highly accurate clonal markers to infer cellular relationships. We track native human cells both in vitro and in vivo and relate clonal dynamics to gene expression and chromatin accessibility. Our approach should allow clonal tracking at a 1,000-fold greater scale than with nuclear genome sequencing, with simultaneous information on cell state, opening the way to chart cellular dynamics in human health and disease.
Assuntos
DNA Mitocondrial/genética , Mitocôndrias/genética , Sequência de Bases , Linhagem da Célula , Cromatina , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Genômica/métodos , Células HEK293 , Células-Tronco Hematopoéticas/fisiologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Mutação , Análise de Célula Única , TransposasesRESUMO
Acute myeloid leukemia (AML) is a heterogeneous disease that resides within a complex microenvironment, complicating efforts to understand how different cell types contribute to disease progression. We combined single-cell RNA sequencing and genotyping to profile 38,410 cells from 40 bone marrow aspirates, including 16 AML patients and five healthy donors. We then applied a machine learning classifier to distinguish a spectrum of malignant cell types whose abundances varied between patients and between subclones in the same tumor. Cell type compositions correlated with prototypic genetic lesions, including an association of FLT3-ITD with abundant progenitor-like cells. Primitive AML cells exhibited dysregulated transcriptional programs with co-expression of stemness and myeloid priming genes and had prognostic significance. Differentiated monocyte-like AML cells expressed diverse immunomodulatory genes and suppressed T cell activity in vitro. In conclusion, we provide single-cell technologies and an atlas of AML cell states, regulators, and markers with implications for precision medicine and immune therapies. VIDEO ABSTRACT.
Assuntos
Leucemia Mieloide Aguda/genética , Transcriptoma/genética , Adulto , Sequência de Bases/genética , Medula Óssea , Células da Medula Óssea/citologia , Linhagem Celular Tumoral , Progressão da Doença , Feminino , Genótipo , Humanos , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/fisiopatologia , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Mutação , Prognóstico , RNA , Transdução de Sinais , Análise de Célula Única/métodos , Microambiente Tumoral , Sequenciamento do Exoma/métodosRESUMO
Dendritic cells (DCs) play a critical role in orchestrating adaptive immune responses due to their unique ability to initiate T cell responses and direct their differentiation into effector lineages. Classical DCs have been divided into two subsets, cDC1 and cDC2, based on phenotypic markers and their distinct abilities to prime CD8 and CD4 T cells. While the transcriptional regulation of the cDC1 subset has been well characterized, cDC2 development and function remain poorly understood. By combining transcriptional and chromatin analyses with genetic reporter expression, we identified two principal cDC2 lineages defined by distinct developmental pathways and transcriptional regulators, including T-bet and RORγt, two key transcription factors known to define innate and adaptive lymphocyte subsets. These novel cDC2 lineages were characterized by distinct metabolic and functional programs. Extending our findings to humans revealed conserved DC heterogeneity and the presence of the newly defined cDC2 subsets in human cancer.
Assuntos
Diferenciação Celular/genética , Linhagem da Célula/genética , Heterogeneidade Genética , Neoplasias/imunologia , Imunidade Adaptativa/genética , Animais , Diferenciação Celular/imunologia , Cromatina/genética , Células Dendríticas/imunologia , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Imunidade Inata/genética , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Camundongos , Neoplasias/genética , Linfócitos T/imunologia , Linfócitos T/metabolismo , Transcrição Gênica/imunologiaRESUMO
C-type lectin receptors (CLRs) expressed by myeloid cells constitute a versatile family of receptors that play a key role in innate immune recognition. Myeloid CLRs exhibit a remarkable ability to recognize an extensive array of ligands, from carbohydrates and beyond, and encompass pattern-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs), and markers of altered self. These receptors, classified into distinct subgroups, play pivotal roles in immune recognition and modulation of immune responses. Their intricate signaling pathways orchestrate a spectrum of cellular responses, influencing processes such as phagocytosis, cytokine production, and antigen presentation. Beyond their contributions to host defense in viral, bacterial, fungal, and parasitic infections, myeloid CLRs have been implicated in non-infectious diseases such as cancer, allergies, and autoimmunity. A nuanced understanding of myeloid CLR interactions with endogenous and microbial triggers is starting to uncover the context-dependent nature of their roles in innate immunity, with implications for therapeutic intervention.
Assuntos
Lectinas Tipo C , Neoplasias , Humanos , Lectinas Tipo C/metabolismo , Imunidade Inata , Células Mieloides/metabolismo , Transdução de Sinais , Neoplasias/metabolismo , Receptores de Reconhecimento de Padrão/metabolismoRESUMO
Immunosuppressive macrophages restrict anti-cancer immunity in glioblastoma (GBM). Here, we studied the contribution of microglia (MGs) and monocyte-derived macrophages (MDMs) to immunosuppression and mechanisms underlying their regulatory function. MDMs outnumbered MGs at late tumor stages and suppressed T cell activity. Molecular and functional analysis identified a population of glycolytic MDM expressing GLUT1 with potent immunosuppressive activity. GBM-derived factors promoted high glycolysis, lactate, and interleukin-10 (IL-10) production in MDMs. Inhibition of glycolysis or lactate production in MDMs impaired IL-10 expression and T cell suppression. Mechanistically, intracellular lactate-driven histone lactylation promoted IL-10 expression, which was required to suppress T cell activity. GLUT1 expression on MDMs was induced downstream of tumor-derived factors that activated the PERK-ATF4 axis. PERK deletion in MDM abrogated histone lactylation, led to the accumulation of intratumoral T cells and tumor growth delay, and, in combination with immunotherapy, blocked GBM progression. Thus, PERK-driven glucose metabolism promotes MDM immunosuppressive activity via histone lactylation.
Assuntos
Glioblastoma , Glucose , Histonas , Macrófagos , Glioblastoma/imunologia , Glioblastoma/metabolismo , Glioblastoma/patologia , Animais , Histonas/metabolismo , Camundongos , Macrófagos/imunologia , Macrófagos/metabolismo , Glucose/metabolismo , Humanos , Linhagem Celular Tumoral , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Transportador de Glucose Tipo 1/metabolismo , Transportador de Glucose Tipo 1/genética , Interleucina-10/metabolismo , Glicólise , Microglia/metabolismo , Microglia/imunologia , Camundongos Endogâmicos C57BL , Linfócitos T/imunologia , Linfócitos T/metabolismo , Tolerância ImunológicaRESUMO
The fusion oncoprotein CBFß-SMMHC, expressed in leukemia cases with chromosome 16 inversion, drives leukemia development and maintenance by altering the activity of the transcription factor RUNX1. Here, we demonstrate that CBFß-SMMHC maintains cell viability by neutralizing RUNX1-mediated repression of MYC expression. Upon pharmacologic inhibition of the CBFß-SMMHC/RUNX1 interaction, RUNX1 shows increased binding at three MYC distal enhancers, where it represses MYC expression by mediating the replacement of the SWI/SNF complex component BRG1 with the polycomb-repressive complex component RING1B, leading to apoptosis. Combining the CBFß-SMMHC inhibitor with the BET inhibitor JQ1 eliminates inv(16) leukemia in human cells and a mouse model. Enhancer-interaction analysis indicated that the three enhancers are physically connected with the MYC promoter, and genome-editing analysis demonstrated that they are functionally implicated in deregulation of MYC expression. This study reveals a mechanism whereby CBFß-SMMHC drives leukemia maintenance and suggests that inhibitors targeting chromatin activity may prove effective in inv(16) leukemia therapy.
Assuntos
Apoptose , Cromatina/metabolismo , Proteínas de Fusão Oncogênica/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-myc/metabolismo , Animais , Apoptose/efeitos dos fármacos , Azepinas/farmacologia , Azepinas/uso terapêutico , Benzimidazóis/farmacologia , Benzimidazóis/uso terapêutico , Linhagem Celular Tumoral , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/metabolismo , Inversão Cromossômica/efeitos dos fármacos , Subunidade alfa 2 de Fator de Ligação ao Core/química , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , DNA/química , DNA/metabolismo , DNA Helicases/metabolismo , Modelos Animais de Doenças , Humanos , Estimativa de Kaplan-Meier , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Nucleares/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Proto-Oncogênicas c-myc/genética , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Triazóis/farmacologia , Triazóis/uso terapêuticoRESUMO
Therapeutic harnessing of adaptive immunity via checkpoint inhibition has transformed the treatment of many cancers. Despite unprecedented long-term responses, most patients do not respond to these therapies. Immunotherapy non-responders often harbor high levels of circulating myeloid-derived suppressor cells (MDSCs)-an immunosuppressive innate cell population. Through genetic and pharmacological approaches, we uncovered a pathway governing MDSC abundance in multiple cancer types. Therapeutic liver-X nuclear receptor (LXR) agonism reduced MDSC abundance in murine models and in patients treated in a first-in-human dose escalation phase 1 trial. MDSC depletion was associated with activation of cytotoxic T lymphocyte (CTL) responses in mice and patients. The LXR transcriptional target ApoE mediated these effects in mice, where LXR/ApoE activation therapy elicited robust anti-tumor responses and also enhanced T cell activation during various immune-based therapies. We implicate the LXR/ApoE axis in the regulation of innate immune suppression and as a target for enhancing the efficacy of cancer immunotherapy in patients.