RESUMO
Inflammation of non-barrier immunologically quiescent tissues is associated with a massive influx of blood-borne innate and adaptive immune cells. Cues from the latter are likely to alter and expand activated states of the resident cells. However, local communications between immigrant and resident cell types in human inflammatory disease remain poorly understood. Here, we explored drivers of fibroblast-like synoviocyte (FLS) heterogeneity in inflamed joints of patients with rheumatoid arthritis using paired single-cell RNA and ATAC sequencing, multiplexed imaging and spatial transcriptomics along with in vitro modeling of cell-extrinsic factor signaling. These analyses suggest that local exposures to myeloid and T cell-derived cytokines, TNF, IFN-γ, IL-1ß or lack thereof, drive four distinct FLS states some of which closely resemble fibroblast states in other disease-affected tissues including skin and colon. Our results highlight a role for concurrent, spatially distributed cytokine signaling within the inflamed synovium.
Assuntos
Artrite Reumatoide , Humanos , Células Cultivadas , Artrite Reumatoide/genética , Membrana Sinovial , Citocinas/metabolismo , FibroblastosRESUMO
T cell activation, a key early event in the adaptive immune response, is subject to elaborate transcriptional control. In the present study, we examined how the activities of eight major transcription factor (TF) families are integrated to shape the epigenome of naive and activated CD4 and CD8 T cells. By leveraging extensive polymorphisms in evolutionarily divergent mice, we identified the 'heavy lifters' positively influencing chromatin accessibility. Members of Ets, Runx and TCF/Lef TF families occupied the vast majority of accessible chromatin regions, acting as 'housekeepers', 'universal amplifiers' and 'placeholders', respectively, at sites that maintained or gained accessibility upon T cell activation. In addition, a small subset of strongly induced immune response genes displayed a noncanonical TF recruitment pattern. Our study provides a key resource and foundation for the understanding of transcriptional and epigenetic regulation in T cells and offers a new perspective on the hierarchical interactions between critical TFs.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Epigenoma/imunologia , Ativação Linfocitária/imunologia , Fatores de Transcrição/imunologia , Imunidade Adaptativa/imunologia , Animais , Cromatina/imunologia , Epigênese Genética/imunologia , Regulação da Expressão Gênica/imunologia , Masculino , CamundongosRESUMO
Malignancy can be suppressed by the immune system. However, the classes of immunosurveillance responses and their mode of tumor sensing remain incompletely understood. Here, we show that although clear cell renal cell carcinoma (ccRCC) was infiltrated by exhaustion-phenotype CD8+ T cells that negatively correlated with patient prognosis, chromophobe RCC (chRCC) had abundant infiltration of granzyme A-expressing intraepithelial type 1 innate lymphoid cells (ILC1s) that positively associated with patient survival. Interleukin-15 (IL-15) promoted ILC1 granzyme A expression and cytotoxicity, and IL-15 expression in chRCC tumor tissue positively tracked with the ILC1 response. An ILC1 gene signature also predicted survival of a subset of breast cancer patients in association with IL-15 expression. Notably, ILC1s directly interacted with cancer cells, and IL-15 produced by cancer cells supported the expansion and anti-tumor function of ILC1s in a murine breast cancer model. Thus, ILC1 sensing of cancer cell IL-15 defines an immunosurveillance mechanism of epithelial malignancies.
Assuntos
Neoplasias da Mama , Interleucina-15/metabolismo , Animais , Neoplasias da Mama/genética , Linfócitos T CD8-Positivos , Feminino , Granzimas , Humanos , Imunidade Inata , Linfócitos , CamundongosRESUMO
Tumors develop by invoking a supportive environment characterized by aberrant angiogenesis and infiltration of tumor-associated macrophages (TAMs). In a transgenic model of breast cancer, we found that TAMs localized to the tumor parenchyma and were smaller than mammary tissue macrophages. TAMs had low activity of the metabolic regulator mammalian/mechanistic target of rapamycin complex 1 (mTORC1), and depletion of negative regulator of mTORC1 signaling, tuberous sclerosis complex 1 (TSC1), in TAMs inhibited tumor growth in a manner independent of adaptive lymphocytes. Whereas wild-type TAMs exhibited inflammatory and angiogenic gene expression profiles, TSC1-deficient TAMs had a pro-resolving phenotype. TSC1-deficient TAMs relocated to a perivascular niche, depleted protein C receptor (PROCR)-expressing endovascular endothelial progenitor cells, and rectified the hyperpermeable blood vasculature, causing tumor tissue hypoxia and cancer cell death. TSC1-deficient TAMs were metabolically active and effectively eliminated PROCR-expressing endothelial cells in cell competition experiments. Thus, TAMs exhibit a TSC1-dependent mTORC1-low state, and increasing mTORC1 signaling promotes a pro-resolving state that suppresses tumor growth, defining an innate immune tumor suppression pathway that may be exploited for cancer immunotherapy.
Assuntos
Células Progenitoras Endoteliais , Proteínas Supressoras de Tumor , Animais , Humanos , Serina-Treonina Quinases TOR/metabolismo , Proteína 1 do Complexo Esclerose Tuberosa/genética , Macrófagos Associados a Tumor/metabolismo , Células Progenitoras Endoteliais/metabolismo , Receptor de Proteína C Endotelial , Alvo Mecanístico do Complexo 1 de Rapamicina , Neovascularização Patológica , MamíferosRESUMO
Infection is restrained by the concerted activation of tissue-resident and circulating immune cells. Whether tissue-resident lymphocytes confer early antiviral immunity at local sites of primary infection prior to the initiation of circulating responses is not well understood. Furthermore, the kinetics of initial antiviral responses at sites of infection remain unclear. Here, we show that tissue-resident type 1 innate lymphoid cells (ILC1) serve an essential early role in host immunity through rapid production of interferon (IFN)-γ following viral infection. Ablation of Zfp683-dependent liver ILC1 lead to increased viral load in the presence of intact adaptive and innate immune cells critical for mouse cytomegalovirus (MCMV) clearance. Swift production of interleukin (IL)-12 by tissue-resident XCR1+ conventional dendritic cells (cDC1) promoted ILC1 production of IFN-γ in a STAT4-dependent manner to limit early viral burden. Thus, ILC1 contribute an essential role in viral immunosurveillance at sites of initial infection in response to local cDC1-derived proinflammatory cytokines.
Assuntos
Infecções por Herpesviridae/imunologia , Linfócitos/imunologia , Muromegalovirus/fisiologia , Animais , Infecções por Herpesviridae/patologia , Imunidade Inata , Vigilância Imunológica , Inflamação/imunologia , Interferon gama/imunologia , Células Matadoras Naturais/imunologia , Fígado/citologia , Fígado/imunologia , Camundongos Endogâmicos C57BL , Cavidade Peritoneal/citologia , Replicação ViralRESUMO
Regulatory T cells (Treg cells), whose differentiation and function are controlled by transcription factor Foxp3, express the closely related family member Foxp1. Here we explored Foxp1 function in Treg cells. We found that a large number of Foxp3-bound genomic sites in Treg cells were occupied by Foxp1 in both Treg cells and conventional T cells (Tconv cells). In Treg cells, Foxp1 markedly increased Foxp3 binding to these sites. Foxp1 deficiency in Treg cells resulted in their impaired function and competitive fitness, associated with markedly reduced CD25 expression and interleukin-2 (IL-2) responsiveness, diminished CTLA-4 expression and increased SATB1 expression. The characteristic expression patterns of CD25, Foxp3 and CTLA-4 in Treg cells were fully or partially rescued by strong IL-2 signaling. Our studies suggest that Foxp1 serves an essential non-redundant function in Treg cells by enforcing Foxp3-mediated regulation of gene expression and enabling efficient IL-2 signaling in these cells.
Assuntos
Cromatina/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica/imunologia , Proteínas Repressoras/metabolismo , Linfócitos T Reguladores/metabolismo , Animais , Células Cultivadas , Feminino , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/imunologia , Interleucina-2/imunologia , Interleucina-2/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Cultura Primária de Células , Proteínas Repressoras/genética , Proteínas Repressoras/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T Reguladores/imunologiaRESUMO
Innate lymphoid cells (ILCs) are tissue-resident sentinels that are essential for early host protection from pathogens at initial sites of infection. However, whether pathogen-derived antigens directly modulate the responses of tissue-resident ILCs has remained unclear. In the present study, it was found that liver-resident type 1 ILCs (ILC1s) expanded locally and persisted after the resolution of infection with mouse cytomegalovirus (MCMV). ILC1s acquired stable transcriptional, epigenetic and phenotypic changes a month after the resolution of MCMV infection, and showed an enhanced protective effector response to secondary challenge with MCMV consistent with a memory lymphocyte response. Memory ILC1 responses were dependent on the MCMV-encoded glycoprotein m12, and were independent of bystander activation by proinflammatory cytokines after heterologous infection. Thus, liver ILC1s acquire adaptive features in an MCMV-specific manner.
Assuntos
Memória Imunológica/imunologia , Fígado/imunologia , Linfócitos/imunologia , Glicoproteínas de Membrana/imunologia , Muromegalovirus/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Infecções por Herpesviridae/imunologia , Infecções por Herpesviridae/virologia , Imunidade Inata/imunologia , Subunidade alfa de Receptor de Interleucina-18/metabolismo , Fígado/citologia , CamundongosRESUMO
Eukaryotic cells can "remember" transient encounters with a wide range of stimuli, inducing lasting states of altered responsiveness. Regulatory T (Treg) cells are a specialized lineage of suppressive CD4 T cells that act as critical negative regulators of inflammation in various biological contexts. Treg cells exposed to inflammatory conditions acquire strongly enhanced suppressive function. Using inducible genetic tracing, we analyzed the long-term stability of activation-induced transcriptional, epigenomic, and functional changes in Treg cells. We found that the inflammation-experienced Treg cell population reversed many activation-induced changes and lost its enhanced suppressive function over time. The "memory-less" potentiation of Treg suppressor function may help avoid a state of generalized immunosuppression that could otherwise result from repeated activation.
Assuntos
Linfócitos T Reguladores/imunologia , Animais , Diferenciação Celular , Cromatina/metabolismo , Memória Imunológica , Inflamação/metabolismo , Ativação Linfocitária , Camundongos , Organismos Livres de Patógenos Específicos , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/metabolismo , Transcrição GênicaRESUMO
Malignancy can be suppressed by the immune system in a process termed immunosurveillance. However, to what extent immunosurveillance occurs in spontaneous cancers and the composition of participating cell types remains obscure. Here, we show that cell transformation triggers a tissue-resident lymphocyte response in oncogene-induced murine cancer models. Non-circulating cytotoxic lymphocytes, derived from innate, T cell receptor (TCR)αß, and TCRγδ lineages, expand in early tumors. Characterized by high expression of NK1.1, CD49a, and CD103, these cells share a gene-expression signature distinct from those of conventional NK cells, T cells, and invariant NKT cells. Generation of these lymphocytes is dependent on the cytokine IL-15, but not the transcription factor Nfil3 that is required for the differentiation of tumor-infiltrating NK cells, and IL-15 deficiency, but not Nfil3 deficiency, results in accelerated tumor growth. These findings reveal a tumor-elicited immunosurveillance mechanism that engages unconventional type-1-like innate lymphoid cells and type 1 innate-like T cells.
Assuntos
Linfócitos/imunologia , Neoplasias Mamárias Experimentais/imunologia , Monitorização Imunológica , Subpopulações de Linfócitos T/imunologia , Animais , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Granzimas/metabolismo , Interleucina-15/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismoRESUMO
The four-dimensional nucleome (4DN) consortium studies the architecture of the genome and the nucleus in space and time. We summarize progress by the consortium and highlight the development of technologies for (1) mapping genome folding and identifying roles of nuclear components and bodies, proteins, and RNA, (2) characterizing nuclear organization with time or single-cell resolution, and (3) imaging of nuclear organization. With these tools, the consortium has provided over 2,000 public datasets. Integrative computational models based on these data are starting to reveal connections between genome structure and function. We then present a forward-looking perspective and outline current aims to (1) delineate dynamics of nuclear architecture at different timescales, from minutes to weeks as cells differentiate, in populations and in single cells, (2) characterize cis-determinants and trans-modulators of genome organization, (3) test functional consequences of changes in cis- and trans-regulators, and (4) develop predictive models of genome structure and function.
Assuntos
Núcleo Celular , Genoma , Genoma/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Cromatina/metabolismoRESUMO
Numerous microRNAs and their target mRNAs are coexpressed across diverse cell types. However, it is unknown whether they are regulated in a manner independent of or dependent on cellular context. Here, we explored transcriptome-wide targeting and gene regulation by miR-155, whose activation-induced expression plays important roles in innate and adaptive immunity. Through mapping of miR-155 targets through differential iCLIP, mRNA quantification with RNA-seq, and 3' untranslated region (UTR)-usage analysis with poly(A)-seq in macrophages, dendritic cells, and T and B lymphocytes either sufficient or deficient in activated miR-155, we identified numerous targets differentially bound by miR-155. Whereas alternative cleavage and polyadenylation (ApA) contributed to differential miR-155 binding to some transcripts, in most cases, identical 3'-UTR isoforms were differentially regulated across cell types, thus suggesting ApA-independent and cellular-context-dependent miR-155-mediated gene regulation. Our study provides comprehensive maps of miR-155 regulatory networks and offers a valuable resource for dissecting context-dependent and context-independent miRNA-mediated gene regulation in key immune cell types.
Assuntos
Linfócitos B/imunologia , Células Dendríticas/imunologia , Regulação da Expressão Gênica/imunologia , Macrófagos/imunologia , MicroRNAs/imunologia , Linfócitos T/imunologia , Animais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Clonal expansion and immunological memory are hallmark features of the mammalian adaptive immune response and essential for prolonged host control of pathogens. Recent work demonstrates that natural killer (NK) cells of the innate immune system also exhibit these adaptive traits during infection. Here we demonstrate that differentiating and 'memory' NK cells possess distinct chromatin accessibility states and that their epigenetic profiles reveal a 'poised' regulatory program at the memory stage. Furthermore, we elucidate how individual STAT transcription factors differentially control epigenetic and transcriptional states early during infection. Finally, concurrent chromatin profiling of the canonical CD8+ T cell response against the same infection demonstrated parallel and distinct epigenetic signatures defining NK cells and CD8+ T cells. Overall, our study reveals the dynamic nature of epigenetic modifications during the generation of innate and adaptive lymphocyte memory.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Cromatina/metabolismo , Infecções por Herpesviridae/imunologia , Células Matadoras Naturais/fisiologia , Muromegalovirus/fisiologia , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT4/metabolismo , Imunidade Adaptativa , Animais , Células Cultivadas , Cromatina/genética , Seleção Clonal Mediada por Antígeno , Epigênese Genética , Perfilação da Expressão Gênica , Imunidade Inata , Memória Imunológica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT4/genéticaRESUMO
Aerobic glycolysis-the Warburg effect-converts glucose to lactate via the enzyme lactate dehydrogenase A (LDHA) and is a metabolic feature of effector T cells. Cells generate ATP through various mechanisms and Warburg metabolism is comparatively an energy-inefficient glucose catabolism pathway. Here, we examined the effect of ATP generated via aerobic glycolysis in antigen-driven T cell responses. Cd4CreLdhafl/fl mice were resistant to Th17-cell-mediated experimental autoimmune encephalomyelitis and exhibited defective T cell activation, migration, proliferation, and differentiation. LDHA deficiency crippled cellular redox balance and inhibited ATP production, diminishing PI3K-dependent activation of Akt kinase and thereby phosphorylation-mediated inhibition of Foxo1, a transcriptional repressor of T cell activation programs. Th17-cell-specific expression of an Akt-insensitive Foxo1 recapitulated the defects seen in Cd4CreLdhafl/fl mice. Induction of LDHA required PI3K signaling and LDHA deficiency impaired PI3K-catalyzed PIP3 generation. Thus, Warburg metabolism augments glycolytic ATP production, fueling a PI3K-centered positive feedback regulatory circuit that drives effector T cell responses.
Assuntos
Trifosfato de Adenosina/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Transdução de Sinais/fisiologia , Células Th17/metabolismo , Animais , Diferenciação Celular/fisiologia , Linhagem Celular , Proliferação de Células/fisiologia , Feminino , Regulação Neoplásica da Expressão Gênica/fisiologia , Glucose/metabolismo , Doença de Depósito de Glicogênio/metabolismo , Glicólise/fisiologia , L-Lactato Desidrogenase/deficiência , L-Lactato Desidrogenase/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos TransgênicosRESUMO
The pace of human brain development is highly protracted compared with most other species1-7. The maturation of cortical neurons is particularly slow, taking months to years to develop adult functions3-5. Remarkably, such protracted timing is retained in cortical neurons derived from human pluripotent stem cells (hPSCs) during in vitro differentiation or upon transplantation into the mouse brain4,8,9. Those findings suggest the presence of a cell-intrinsic clock setting the pace of neuronal maturation, although the molecular nature of this clock remains unknown. Here we identify an epigenetic developmental programme that sets the timing of human neuronal maturation. First, we developed a hPSC-based approach to synchronize the birth of cortical neurons in vitro which enabled us to define an atlas of morphological, functional and molecular maturation. We observed a slow unfolding of maturation programmes, limited by the retention of specific epigenetic factors. Loss of function of several of those factors in cortical neurons enables precocious maturation. Transient inhibition of EZH2, EHMT1 and EHMT2 or DOT1L, at progenitor stage primes newly born neurons to rapidly acquire mature properties upon differentiation. Thus our findings reveal that the rate at which human neurons mature is set well before neurogenesis through the establishment of an epigenetic barrier in progenitor cells. Mechanistically, this barrier holds transcriptional maturation programmes in a poised state that is gradually released to ensure the prolonged timeline of human cortical neuron maturation.
Assuntos
Epigênese Genética , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Embrionárias Humanas , Células-Tronco Neurais , Neurogênese , Neurônios , Adulto , Animais , Humanos , Camundongos , Antígenos de Histocompatibilidade/metabolismo , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Histona-Lisina N-Metiltransferase/metabolismo , Células-Tronco Embrionárias Humanas/citologia , Células-Tronco Embrionárias Humanas/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Neurônios/citologia , Neurônios/metabolismo , Fatores de Tempo , Transcrição GênicaRESUMO
Regulatory T (Treg) cell identity is defined by the lineage-specifying transcription factor (TF) Foxp3. Here we examined mechanisms of Foxp3 function by leveraging naturally occurring genetic variation in wild-derived inbred mice, which enables the identification of DNA sequence motifs driving epigenetic features. Chromatin accessibility, TF binding, and gene expression patterns in resting and activated subsets of Treg cells, conventional CD4 T cells, and cells expressing a Foxp3 reporter null allele revealed that the majority of Foxp3-dependent changes occurred at sites not bound by Foxp3. Chromatin accessibility of these indirect Foxp3 targets depended on the presence of DNA binding motifs for other TFs, including TCF1. Foxp3 expression correlated with decreased TCF1 and reduced accessibility of TCF1-bound chromatin regions. Deleting one copy of the Tcf7 gene recapitulated Foxp3-dependent negative regulation of chromatin accessibility. Thus, Foxp3 defines Treg cell identity in a largely indirect manner by fine-tuning the activity of other major chromatin remodeling TFs such as TCF1.
Assuntos
Fatores de Transcrição Forkhead/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Animais , Doenças Autoimunes/etiologia , Doenças Autoimunes/metabolismo , Doenças Autoimunes/patologia , Autoimunidade/genética , Sítios de Ligação , Montagem e Desmontagem da Cromatina , Modelos Animais de Doenças , Epigênese Genética , Feminino , Fatores de Transcrição Forkhead/genética , Regulação da Expressão Gênica , Imuno-Histoquímica , Masculino , Camundongos , Motivos de Nucleotídeos , Especificidade de Órgãos/genética , Especificidade de Órgãos/imunologia , Ligação Proteica , Transativadores/metabolismoRESUMO
CD8 T cells play an essential role in defense against viral and bacterial infections and in tumor immunity. Deciphering T cell loss of functionality is complicated by the conspicuous heterogeneity of CD8 T cell states described across experimental and clinical settings. By carrying out a unified analysis of over 300 assay for transposase-accessible chromatin sequencing (ATAC-seq) and RNA sequencing (RNA-seq) experiments from 12 studies of CD8 T cells in cancer and infection, we defined a shared differentiation trajectory toward dysfunction and its underlying transcriptional drivers and revealed a universal early bifurcation of functional and dysfunctional T cell states across models. Experimental dissection of acute and chronic viral infection using single-cell ATAC (scATAC)-seq and allele-specific single-cell RNA (scRNA)-seq identified state-specific drivers and captured the emergence of similar TCF1+ progenitor-like populations at an early branch point, at which functional and dysfunctional T cells diverge. Our atlas of CD8 T cell states will facilitate mechanistic studies of T cell immunity and translational efforts.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Epigênese Genética/imunologia , Imunidade Celular , Coriomeningite Linfocítica/genética , Neoplasias/genética , Fatores de Transcrição/genética , Doença Aguda , Atlas como Assunto , Linfócitos T CD8-Positivos/classificação , Linfócitos T CD8-Positivos/patologia , Cromatina/química , Cromatina/imunologia , Doença Crônica , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Ativação Linfocitária , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/patologia , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/patogenicidade , Neoplasias/imunologia , Neoplasias/patologia , Análise de Componente Principal , Análise de Célula Única , Fatores de Transcrição/classificação , Fatores de Transcrição/imunologia , Transcrição Gênica , Transposases/genética , Transposases/metabolismoRESUMO
Stable changes in chromatin states and gene expression in cells of the immune system form the basis for memory of infections and other challenges. Here, we used naturally occurring cis-regulatory variation in wild-derived inbred mouse strains to explore the mechanisms underlying long-lasting versus transient gene regulation in CD8 T cells responding to acute viral infection. Stably responsive DNA elements were characterized by dramatic and congruent chromatin remodeling events affecting multiple neighboring sites and required distinct transcription factor (TF) binding motifs for their accessibility. Specifically, we found that cooperative recruitment of T-box and Runx family transcription factors to shared targets mediated stable chromatin remodeling upon T cell activation. Our observations provide insights into the molecular mechanisms driving virus-specific CD8 T cell responses and suggest a general mechanism for the formation of transcriptional and epigenetic memory applicable to other immune and non-immune cells.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Montagem e Desmontagem da Cromatina/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Regulação da Expressão Gênica/genética , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Proteínas com Domínio T/genética , Animais , Linfócitos T CD8-Positivos/virologia , Linhagem Celular , Cromatina/genética , Epigênese Genética/genética , Feminino , Expressão Gênica/genética , Regulação da Expressão Gênica/imunologia , Variação Genética , Memória Imunológica/genética , Memória Imunológica/imunologia , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Coriomeningite Linfocítica/virologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transcrição Gênica/genéticaRESUMO
Cellular transformation induces phenotypically diverse populations of tumour-infiltrating T cells1-5, and immune checkpoint blockade therapies preferentially target T cells that recognize cancer cell neoantigens6,7. Yet, how other classes of tumour-infiltrating T cells contribute to cancer immunosurveillance remains elusive. Here, in a survey of T cells in mouse and human malignancies, we identified a population of αß T cell receptor (TCR)-positive FCER1G-expressing innate-like T cells with high cytotoxic potential8 (ILTCKs). These cells were broadly reactive to unmutated self-antigens, arose from distinct thymic progenitors following early encounter with cognate antigens, and were continuously replenished by thymic progenitors during tumour progression. Notably, expansion and effector differentiation of intratumoural ILTCKs depended on interleukin-15 (IL-15) expression in cancer cells, and inducible activation of IL-15 signalling in adoptively transferred ILTCK progenitors suppressed tumour growth. Thus, the antigen receptor self-reactivity, unique ontogeny, and distinct cancer cell-sensing mechanism distinguish ILTCKs from conventional cytotoxic T cells, and define a new class of tumour-elicited immune response.
Assuntos
Imunidade Inata , Interleucina-15 , Neoplasias , Animais , Diferenciação Celular , Camundongos , Neoplasias/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T Citotóxicos/metabolismoRESUMO
The identification of microRNA (miRNA) targets by Ago2 crosslinking-immunoprecipitation (CLIP) methods has provided major insights into the biology of this important class of non-coding RNAs. However, these methods are technically challenging and not easily applicable to an in vivo setting. To overcome these limitations and facilitate the investigation of miRNA functions in vivo, we have developed a method based on a genetically engineered mouse harboring a conditional Halo-Ago2 allele expressed from the endogenous Ago2 locus. By using a resin conjugated to the HaloTag ligand, Ago2-miRNA-mRNA complexes can be purified from cells and tissues expressing the endogenous Halo-Ago2 allele. We demonstrate the reproducibility and sensitivity of this method in mouse embryonic stem cells, developing embryos, adult tissues, and autochthonous mouse models of human brain and lung cancers. This method and the datasets we have generated will facilitate the characterization of miRNA-mRNA networks in vivo under physiological and pathological conditions.