RESUMO
Overcoming immune-mediated resistance to PD-1 blockade remains a major clinical challenge. Enhanced efficacy has been demonstrated in melanoma patients with combined nivolumab (anti-PD-1) and relatlimab (anti-LAG-3) treatment, the first in its class to be FDA approved. However, how these two inhibitory receptors synergize to hinder anti-tumor immunity remains unknown. Here, we show that CD8+ T cells deficient in both PD-1 and LAG-3, in contrast to CD8+ T cells lacking either receptor, mediate enhanced tumor clearance and long-term survival in mouse models of melanoma. PD-1- and LAG-3-deficient CD8+ T cells were transcriptionally distinct, with broad TCR clonality and enrichment of effector-like and interferon-responsive genes, resulting in enhanced IFN-γ release indicative of functionality. LAG-3 and PD-1 combined to drive T cell exhaustion, playing a dominant role in modulating TOX expression. Mechanistically, autocrine, cell-intrinsic IFN-γ signaling was required for PD-1- and LAG-3-deficient CD8+ T cells to enhance anti-tumor immunity, providing insight into how combinatorial targeting of LAG-3 and PD-1 enhances efficacy.
Assuntos
Antígenos CD , Linfócitos T CD8-Positivos , Interferon gama , Proteína do Gene 3 de Ativação de Linfócitos , Camundongos Endogâmicos C57BL , Receptor de Morte Celular Programada 1 , Receptor de Morte Celular Programada 1/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Animais , Interferon gama/metabolismo , Camundongos , Antígenos CD/metabolismo , Comunicação Autócrina , Humanos , Melanoma/imunologia , Melanoma/tratamento farmacológico , Feminino , Linhagem Celular Tumoral , Melanoma Experimental/imunologia , Exaustão das Células TRESUMO
Exhausted CD8 T (Tex) cells in chronic viral infection and cancer have sustained co-expression of inhibitory receptors (IRs). Tex cells can be reinvigorated by blocking IRs, such as PD-1, but synergistic reinvigoration and enhanced disease control can be achieved by co-targeting multiple IRs including PD-1 and LAG-3. To dissect the molecular changes intrinsic when these IR pathways are disrupted, we investigated the impact of loss of PD-1 and/or LAG-3 on Tex cells during chronic infection. These analyses revealed distinct roles of PD-1 and LAG-3 in regulating Tex cell proliferation and effector functions, respectively. Moreover, these studies identified an essential role for LAG-3 in sustaining TOX and Tex cell durability as well as a LAG-3-dependent circuit that generated a CD94/NKG2+ subset of Tex cells with enhanced cytotoxicity mediated by recognition of the stress ligand Qa-1b, with similar observations in humans. These analyses disentangle the non-redundant mechanisms of PD-1 and LAG-3 and their synergy in regulating Tex cells.
Assuntos
Antígenos CD , Linfócitos T CD8-Positivos , Antígenos de Histocompatibilidade Classe I , Proteína do Gene 3 de Ativação de Linfócitos , Subfamília D de Receptores Semelhantes a Lectina de Células NK , Receptor de Morte Celular Programada 1 , Animais , Antígenos CD/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Camundongos , Receptor de Morte Celular Programada 1/metabolismo , Subfamília D de Receptores Semelhantes a Lectina de Células NK/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Subfamília C de Receptores Semelhantes a Lectina de Células NK/metabolismo , Camundongos Endogâmicos C57BL , Proteínas de Grupo de Alta Mobilidade/metabolismo , Proteínas de Grupo de Alta Mobilidade/genética , Citotoxicidade Imunológica , Proliferação de Células , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/imunologiaRESUMO
The immune system is capable of recognizing tumors and eliminates many early malignant cells. However, tumors evolve to evade immune attack, and the tumor microenvironment is immunosuppressive. Immune responses are regulated by a number of immunological checkpoints that promote protective immunity and maintain tolerance. T cell coinhibitory pathways restrict the strength and duration of immune responses, thereby limiting immune-mediated tissue damage, controlling resolution of inflammation, and maintaining tolerance to prevent autoimmunity. Tumors exploit these coinhibitory pathways to evade immune eradication. Blockade of the PD-1 and CTLA-4 checkpoints is proving to be an effective and durable cancer immunotherapy in a subset of patients with a variety of tumor types, and additional combinations are further improving response rates. In this review we discuss the immunoregulatory functions of coinhibitory pathways and their translation to effective immunotherapies for cancer.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antígeno B7-H1/imunologia , Antígeno CTLA-4/imunologia , Imunoterapia/métodos , Neoplasias/terapia , Receptor de Morte Celular Programada 1/imunologia , Linfócitos T/imunologia , Animais , Humanos , Imunoterapia/tendências , Ativação Linfocitária/efeitos dos fármacos , Neoplasias/imunologia , Evasão Tumoral , Microambiente TumoralRESUMO
Annotation of immunologic gene function in vivo typically requires the generation of knockout mice, which is time consuming and low throughput. We previously developed CHimeric IMmune Editing (CHIME), a CRISPR-Cas9 bone marrow delivery system for constitutive, ubiquitous deletion of single genes. Here we describe X-CHIME, four new CHIME-based systems for modular and rapid interrogation of gene function combinatorially (C-CHIME), inducibly (I-CHIME), lineage-specifically (L-CHIME) or sequentially (S-CHIME). We use C-CHIME and S-CHIME to assess the consequences of combined deletion of Ptpn1 and Ptpn2, an embryonic lethal gene pair, in adult mice. We find that constitutive deletion of both PTPN1 and PTPN2 leads to bone marrow hypoplasia and lethality, while inducible deletion after immune development leads to enteritis and lethality. These findings demonstrate that X-CHIME can be used for rapid mechanistic evaluation of genes in distinct in vivo contexts and that PTPN1 and PTPN2 have some functional redundancy important for viability in adult mice.
Assuntos
Sistemas CRISPR-Cas , Proteína Tirosina Fosfatase não Receptora Tipo 2 , Camundongos , Animais , Sistemas CRISPR-Cas/genética , Proteína Tirosina Fosfatase não Receptora Tipo 2/genética , Camundongos Knockout , Sistema Imunitário , Edição de GenesRESUMO
The population is aging at a rate never seen before in human history. As the number of elderly adults grows, it is imperative we expand our understanding of the underpinnings of aging biology. Human lungs are composed of a unique panoply of cell types that face ongoing chemical, mechanical, biological, immunological, and xenobiotic stress over a lifetime. Yet, we do not fully appreciate the mechanistic drivers of lung aging and why age increases the risk of parenchymal lung disease, fatal respiratory infection, and primary lung cancer. Here, we review the molecular and cellular aspects of lung aging, local stress response pathways, and how the aging process predisposes to the pathogenesis of pulmonary disease. We place these insights into context of the COVID-19 pandemic and discuss how innate and adaptive immunity within the lung is altered with age.
Assuntos
Envelhecimento , Senescência Celular , Pneumopatias , Pulmão , Imunidade Adaptativa , Idoso , Envelhecimento/imunologia , Envelhecimento/patologia , COVID-19/imunologia , COVID-19/patologia , Humanos , Pulmão/imunologia , Pulmão/patologia , Pneumopatias/imunologia , Pneumopatias/patologia , Estresse OxidativoRESUMO
The process of pyroptosis is mediated by inflammasomes and a downstream effector known as gasdermin D (GSDMD). Upon cleavage by inflammasome-associated caspases, the N-terminal domain of GSDMD forms membrane pores that promote cytolysis. Numerous proteins promote GSDMD cleavage, but none are known to be required for pore formation after GSDMD cleavage. Herein, we report a forward genetic screen that identified the Ragulator-Rag complex as being necessary for GSDMD pore formation and pyroptosis in macrophages. Mechanistic analysis revealed that Ragulator-Rag is not required for GSDMD cleavage upon inflammasome activation but rather promotes GSDMD oligomerization in the plasma membrane. Defects in GSDMD oligomerization and pore formation can be rescued by mitochondrial poisons that stimulate reactive oxygen species (ROS) production, and ROS modulation impacts the ability of inflammasome pathways to promote pore formation downstream of GSDMD cleavage. These findings reveal an unexpected link between key regulators of immunity (inflammasome-GSDMD) and metabolism (Ragulator-Rag).
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Multimerização Proteica , Piroptose , Transdução de Sinais , Aminoácidos/metabolismo , Animais , Moléculas de Adesão Celular Neuronais/metabolismo , Linhagem Celular , Testes Genéticos , Humanos , Inflamassomos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/química , Macrófagos/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Fatores de Crescimento Neural/metabolismo , Proteínas de Ligação a Fosfato/química , Domínios Proteicos , RNA Guia de Cinetoplastídeos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Serina-Treonina Quinases TOR/metabolismoRESUMO
Obesity is a major cancer risk factor, but how differences in systemic metabolism change the tumor microenvironment (TME) and impact anti-tumor immunity is not understood. Here, we demonstrate that high-fat diet (HFD)-induced obesity impairs CD8+ T cell function in the murine TME, accelerating tumor growth. We generate a single-cell resolution atlas of cellular metabolism in the TME, detailing how it changes with diet-induced obesity. We find that tumor and CD8+ T cells display distinct metabolic adaptations to obesity. Tumor cells increase fat uptake with HFD, whereas tumor-infiltrating CD8+ T cells do not. These differential adaptations lead to altered fatty acid partitioning in HFD tumors, impairing CD8+ T cell infiltration and function. Blocking metabolic reprogramming by tumor cells in obese mice improves anti-tumor immunity. Analysis of human cancers reveals similar transcriptional changes in CD8+ T cell markers, suggesting interventions that exploit metabolism to improve cancer immunotherapy.
Assuntos
Imunidade , Neoplasias/imunologia , Neoplasias/metabolismo , Obesidade/metabolismo , Microambiente Tumoral , Adiposidade , Animais , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Proliferação de Células , Dieta Hiperlipídica , Ácidos Graxos/metabolismo , Células HEK293 , Humanos , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Cinética , Linfócitos do Interstício Tumoral , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oxirredução , Análise de Componente Principal , Pró-Colágeno-Prolina Dioxigenase/metabolismo , ProteômicaRESUMO
T cells acquire a regulatory phenotype when their T cell antigen receptors (TCRs) experience an intermediate- to high-affinity interaction with a self-peptide presented via the major histocompatibility complex (MHC). Using TCRß sequences from flow-sorted human cells, we identified TCR features that promote regulatory T cell (Treg) fate. From these results, we developed a scoring system to quantify TCR-intrinsic regulatory potential (TiRP). When applied to the tumor microenvironment, TiRP scoring helped to explain why only some T cell clones maintained the conventional T cell (Tconv) phenotype through expansion. To elucidate drivers of these predictive TCR features, we then examined the two elements of the Treg TCR ligand separately: the self-peptide and the human MHC class II molecule. These analyses revealed that hydrophobicity in the third complementarity-determining region (CDR3ß) of the TCR promotes reactivity to self-peptides, while TCR variable gene (TRBV gene) usage shapes the TCR's general propensity for human MHC class II-restricted activation.
Assuntos
Receptores de Antígenos de Linfócitos T alfa-beta , Receptores de Antígenos de Linfócitos T , Linhagem da Célula , Regiões Determinantes de Complementaridade/genética , Peptídeos , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Linfócitos T ReguladoresRESUMO
Phenotypic and transcriptional profiling of regulatory T (Treg) cells at homeostasis reveals that T cell receptor activation promotes Treg cells with an effector phenotype (eTreg) characterized by the production of interleukin-10 and expression of the inhibitory receptor PD-1. At homeostasis, blockade of the PD-1 pathway results in enhanced eTreg cell activity, whereas during infection with Toxoplasma gondii, early interferon-γ upregulates myeloid cell expression of PD-L1 associated with reduced Treg cell populations. In infected mice, blockade of PD-L1, complete deletion of PD-1 or lineage-specific deletion of PD-1 in Treg cells prevents loss of eTreg cells. These interventions resulted in a reduced ratio of pathogen-specific effector T cells: eTreg cells and increased levels of interleukin-10 that mitigated the development of immunopathology, but which could compromise parasite control. Thus, eTreg cell expression of PD-1 acts as a sensor to rapidly tune the pool of eTreg cells at homeostasis and during inflammatory processes.
Assuntos
Antígeno B7-H1 , Receptor de Morte Celular Programada 1 , Linfócitos T Reguladores , Toxoplasmose Animal , Animais , Antígeno B7-H1/imunologia , Homeostase , Interleucina-10/imunologia , Camundongos , Receptor de Morte Celular Programada 1/imunologia , Linfócitos T Reguladores/imunologia , Toxoplasma/imunologia , Toxoplasmose Animal/imunologiaRESUMO
CD8+ T cells are critical mediators of cytotoxic effector function in infection, cancer and autoimmunity. In cancer and chronic viral infection, CD8+ T cells undergo a progressive loss of cytokine production and cytotoxicity, a state termed T cell exhaustion. In autoimmunity, autoreactive CD8+ T cells retain the capacity to effectively mediate the destruction of host tissues. Although the clinical outcome differs in each context, CD8+ T cells are chronically exposed to antigen in all three. These chronically stimulated CD8+ T cells share some common phenotypic features, as well as transcriptional and epigenetic programming, across disease contexts. A better understanding of these CD8+ T cell states may reveal novel strategies to augment clearance of chronic viral infection and cancer and to mitigate self-reactivity leading to tissue damage in autoimmunity.
Assuntos
Doenças Autoimunes/imunologia , Autoimunidade , Linfócitos T CD8-Positivos/imunologia , Doenças Transmissíveis/imunologia , Linfócitos do Interstício Tumoral/imunologia , Neoplasias/imunologia , Animais , Doenças Autoimunes/genética , Doenças Autoimunes/metabolismo , Antígeno B7-H1/imunologia , Antígeno B7-H1/metabolismo , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Doença Crônica , Doenças Transmissíveis/genética , Doenças Transmissíveis/metabolismo , Citocinas/imunologia , Citocinas/metabolismo , Epigênese Genética , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Fenótipo , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de SinaisRESUMO
Immune responses must be tightly regulated to ensure both optimal protective immunity and tolerance. Costimulatory pathways within the B7:CD28 family provide essential signals for optimal T cell activation and clonal expansion. They provide crucial inhibitory signals that maintain immune homeostasis, control resolution of inflammation, regulate host defense, and promote tolerance to prevent autoimmunity. Tumors and chronic pathogens can exploit these pathways to evade eradication by the immune system. Advances in understanding B7:CD28 pathways have ushered in a new era of immunotherapy with effective drugs to treat cancer, autoimmune diseases, infectious diseases, and transplant rejection. Here, we discuss current understanding of the mechanisms underlying the coinhibitory functions of CTLA-4, PD-1, PD-L1:B7-1 and PD-L2:RGMb interactions and less studied B7 family members, including HHLA2, VISTA, BTNL2, and BTN3A1, as well as their overlapping and unique roles in regulating immune responses, and the therapeutic potential of these insights.
Assuntos
Doenças Autoimunes , Antígenos CD28 , Humanos , Antígenos CD28/metabolismo , Amigos , Linfócitos T , Antígeno CTLA-4/metabolismo , Imunoterapia , Antígeno B7-1/metabolismo , Imunoglobulinas/metabolismo , Butirofilinas/metabolismo , Antígenos CD/metabolismoRESUMO
Chromatin regulators play a broad role in regulating gene expression and, when gone awry, can lead to cancer. Here, we demonstrate that ablation of the histone demethylase LSD1 in cancer cells increases repetitive element expression, including endogenous retroviral elements (ERVs), and decreases expression of RNA-induced silencing complex (RISC) components. Significantly, this leads to double-stranded RNA (dsRNA) stress and activation of type 1 interferon, which stimulates anti-tumor T cell immunity and restrains tumor growth. Furthermore, LSD1 depletion enhances tumor immunogenicity and T cell infiltration in poorly immunogenic tumors and elicits significant responses of checkpoint blockade-refractory mouse melanoma to anti-PD-1 therapy. Consistently, TCGA data analysis shows an inverse correlation between LSD1 expression and CD8+ T cell infiltration in various human cancers. Our study identifies LSD1 as a potent inhibitor of anti-tumor immunity and responsiveness to immunotherapy and suggests LSD1 inhibition combined with PD-(L)1 blockade as a novel cancer treatment strategy.
Assuntos
Retrovirus Endógenos/genética , Histona Desmetilases/metabolismo , Complexo de Inativação Induzido por RNA/genética , Animais , Linhagem Celular Tumoral , Cromatina , Terapia Combinada , Regulação da Expressão Gênica/genética , Histona Desmetilases/genética , Humanos , Imunidade Celular , Imunoterapia , Interferon Tipo I , Células MCF-7 , Camundongos , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/metabolismo , RNA de Cadeia Dupla/genética , Linfócitos TAssuntos
Calcineurina , Calcineurina/metabolismo , Calcineurina/genética , Animais , Humanos , Camundongos , Regulação da Expressão Gênica , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/genética , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição NFATC/metabolismo , Fatores de Transcrição NFATC/genéticaRESUMO
Follicular regulatory T (TFR) cells have specialized roles in modulating follicular helper T (TFH) cell activation of B cells. However, the precise role of TFR cells in controlling antibody responses to foreign antigens and autoantigens in vivo is still unclear due to a lack of specific tools. A TFR cell-deleter mouse was developed that selectively deletes TFR cells, facilitating temporal studies. TFR cells were found to regulate early, but not late, germinal center (GC) responses to control antigen-specific antibody and B cell memory. Deletion of TFR cells also resulted in increased self-reactive immunoglobulin (Ig) G and IgE. The increased IgE levels led us to interrogate the role of TFR cells in house dust mite models. TFR cells were found to control TFH13 cell-induced IgE. In vivo, loss of TFR cells increased house-dust-mite-specific IgE and lung inflammation. Thus, TFR cells control IgG and IgE responses to vaccines, allergens and autoantigens, and exert critical immunoregulatory functions before GC formation.
Assuntos
Linfócitos B/imunologia , Centro Germinativo/imunologia , Hipersensibilidade/imunologia , Pneumonia/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Animais , Antígenos de Dermatophagoides/imunologia , Autoantígenos/imunologia , Deleção Clonal/genética , Modelos Animais de Doenças , Humanos , Tolerância Imunológica , Imunidade Humoral , Imunoglobulina E/metabolismo , Imunoglobulina G/metabolismo , Memória Imunológica , Interleucina-13/metabolismo , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pyroglyphidae/imunologiaRESUMO
CD8+ T cell exhaustion is a state of dysfunction acquired in chronic viral infection and cancer, characterized by the formation of Slamf6+ progenitor exhausted and Tim-3+ terminally exhausted subpopulations through unknown mechanisms. Here we establish the phosphatase PTPN2 as a new regulator of the differentiation of the terminally exhausted subpopulation that functions by attenuating type 1 interferon signaling. Deletion of Ptpn2 in CD8+ T cells increased the generation, proliferative capacity and cytotoxicity of Tim-3+ cells without altering Slamf6+ numbers during lymphocytic choriomeningitis virus clone 13 infection. Likewise, Ptpn2 deletion in CD8+ T cells enhanced Tim-3+ anti-tumor responses and improved tumor control. Deletion of Ptpn2 throughout the immune system resulted in MC38 tumor clearance and improved programmed cell death-1 checkpoint blockade responses to B16 tumors. Our results indicate that increasing the number of cytotoxic Tim-3+CD8+ T cells can promote effective anti-tumor immunity and implicate PTPN2 in immune cells as an attractive cancer immunotherapy target.
Assuntos
Adenocarcinoma/imunologia , Linfócitos T CD8-Positivos/fisiologia , Neoplasias do Colo/imunologia , Imunoterapia/métodos , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/fisiologia , Células Progenitoras Linfoides/fisiologia , Melanoma/imunologia , Proteína Tirosina Fosfatase não Receptora Tipo 2/metabolismo , Neoplasias Cutâneas/imunologia , Animais , Senescência Celular , Citotoxicidade Imunológica , Feminino , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Tolerância Imunológica , Interferon Tipo I/metabolismo , Masculino , Melanoma Experimental , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteína Tirosina Fosfatase não Receptora Tipo 2/genética , Transdução de Sinais , Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismoRESUMO
Lymph node fibroblastic reticular cells (FRCs) respond to signals from activated T cells by releasing nitric oxide, which inhibits T cell proliferation and restricts the size of the expanding T cell pool. Whether interactions with FRCs also support the function or differentiation of activated CD8+ T cells is not known. Here we report that encounters with FRCs enhanced cytokine production and remodeled chromatin accessibility in newly activated CD8+ T cells via interleukin-6. These epigenetic changes facilitated metabolic reprogramming and amplified the activity of pro-survival pathways through differential transcription factor activity. Accordingly, FRC conditioning significantly enhanced the persistence of virus-specific CD8+ T cells in vivo and augmented their differentiation into tissue-resident memory T cells. Our study demonstrates that FRCs play a role beyond restricting T cell expansion-they can also shape the fate and function of CD8+ T cells.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Fibroblastos/fisiologia , Linfonodos/imunologia , Animais , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Reprogramação Celular , Montagem e Desmontagem da Cromatina , Citotoxicidade Imunológica , Epigênese Genética , Regulação da Expressão Gênica , Memória Imunológica , Interleucina-6/genética , Interleucina-6/metabolismo , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico/metabolismoRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
T cell dysfunction is a hallmark of many cancers, but the basis for T cell dysfunction and the mechanisms by which antibody blockade of the inhibitory receptor PD-1 (anti-PD-1) reinvigorates T cells are not fully understood. Here we show that such therapy acts on a specific subpopulation of exhausted CD8+ tumor-infiltrating lymphocytes (TILs). Dysfunctional CD8+ TILs possess canonical epigenetic and transcriptional features of exhaustion that mirror those seen in chronic viral infection. Exhausted CD8+ TILs include a subpopulation of 'progenitor exhausted' cells that retain polyfunctionality, persist long term and differentiate into 'terminally exhausted' TILs. Consequently, progenitor exhausted CD8+ TILs are better able to control tumor growth than are terminally exhausted T cells. Progenitor exhausted TILs can respond to anti-PD-1 therapy, but terminally exhausted TILs cannot. Patients with melanoma who have a higher percentage of progenitor exhausted cells experience a longer duration of response to checkpoint-blockade therapy. Thus, approaches to expand the population of progenitor exhausted CD8+ T cells might be an important component of improving the response to checkpoint blockade.
Assuntos
Anticorpos Bloqueadores/farmacologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Melanoma Experimental/prevenção & controle , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Animais , Anticorpos Bloqueadores/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Linhagem Celular Tumoral , Feminino , Humanos , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/virologia , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/virologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/prevenção & controle , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/efeitos dos fármacos , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/fisiologia , Melanoma Experimental/imunologia , Melanoma Experimental/virologia , Camundongos Congênicos , Camundongos Endogâmicos C57BL , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismoRESUMO
The glycerol-3-phosphate shuttle (G3PS) is a major NADH shuttle that regenerates reducing equivalents in the cytosol and produces energy in the mitochondria. Here, we demonstrate that G3PS is uncoupled in kidney cancer cells where the cytosolic reaction is â¼4.5 times faster than the mitochondrial reaction. The high flux through cytosolic glycerol-3-phosphate dehydrogenase (GPD) is required to maintain redox balance and support lipid synthesis. Interestingly, inhibition of G3PS by knocking down mitochondrial GPD (GPD2) has no effect on mitochondrial respiration. Instead, loss of GPD2 upregulates cytosolic GPD on a transcriptional level and promotes cancer cell proliferation by increasing glycerol-3-phosphate supply. The proliferative advantage of GPD2 knockdown tumor can be abolished by pharmacologic inhibition of lipid synthesis. Taken together, our results suggest that G3PS is not required to run as an intact NADH shuttle but is instead truncated to support complex lipid synthesis in kidney cancer.
Assuntos
Glicerol-3-Fosfato Desidrogenase (NAD+) , Neoplasias Renais , Lipídeos , Humanos , Glicerol/metabolismo , Glicerol-3-Fosfato Desidrogenase (NAD+)/genética , Glicerol-3-Fosfato Desidrogenase (NAD+)/metabolismo , Glicerolfosfato Desidrogenase/genética , Glicerolfosfato Desidrogenase/metabolismo , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Lipídeos/biossíntese , NAD/metabolismo , Oxirredução , Fosfatos/metabolismoRESUMO
CD4+ T cells share common developmental pathways with CD8+ T cells, and upon maturation, CD4+ T conventional T (Tconv) cells lack phenotypic markers that distinguish these cells from FoxP3+ T regulatory cells. We developed a tamoxifen-inducible ThPOKCreERT2.hCD2 line with Frt sites inserted on either side of the CreERT2-hCD2 cassette, and a Foxp3Ametrine-FlpO strain, expressing Ametrine and FlpO in Foxp3+ cells. Breeding these mice resulted in a CD4conviCreERT2-hCD2 line that allows for the specific manipulation of a gene in CD4+ Tconv cells. As FlpO removes the CreERT2-hCD2 cassette, CD4+ Treg cells are spared from Cre activity, which we refer to as allele conditioning. Comparison with an E8IiCreERT2.GFP mouse that enables inducible targeting of CD8+ T cells, and deletion of two inhibitory receptors, PD-1 and LAG-3, in a melanoma model, support the fidelity of these lines. These engineered mouse strains present a resource for the temporal manipulation of genes in CD4+ T cells and CD4+ Tconv cells.