RESUMEN
Pancreatic ß-cells are essential for survival, being the only cell type capable of insulin secretion. While they are believed to be vulnerable to damage by inflammatory cytokines such as interleukin-1 beta (IL-1ß) and interferon-gamma, we have recently identified physiological roles for cytokine signaling in rodent ß-cells that include the stimulation of antiviral and antimicrobial gene expression and the inhibition of viral replication. In this study, we examine cytokine-stimulated changes in gene expression in human islets using single-cell RNA sequencing. Surprisingly, the global responses of human islets to cytokine exposure were remarkably blunted compared to our previous observations in the mouse. The small population of human islet cells that were cytokine responsive exhibited increased expression of IL-1ß-stimulated antiviral guanylate-binding proteins, just like in the mouse. Most human islet cells were not responsive to cytokines, and this lack of responsiveness was associated with high expression of genes encoding ribosomal proteins. We further correlated the expression levels of RPL5 with stress response genes, and when expressed at high levels, RPL5 is predictive of failure to respond to cytokines in all endocrine cells. We postulate that donor causes of death and isolation methodologies may contribute to stress of the islet preparation. Our findings indicate that activation of stress responses in human islets limits cytokine-stimulated gene expression, and we urge caution in the evaluation of studies that have examined cytokine-stimulated gene expression in human islets without evaluation of stress-related gene expression.
Asunto(s)
Citocinas , Islotes Pancreáticos , Análisis de la Célula Individual , Humanos , Análisis de la Célula Individual/métodos , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/efectos de los fármacos , Citocinas/metabolismo , Citocinas/genética , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/efectos de los fármacos , Análisis de Secuencia de ARN , Estrés Fisiológico/efectos de los fármacos , Interleucina-1beta/metabolismo , Proteínas Ribosómicas/genética , Proteínas Ribosómicas/metabolismo , Masculino , Ratones , Animales , RNA-Seq , Femenino , Persona de Mediana Edad , Análisis de Expresión Génica de una Sola CélulaRESUMEN
Influenza virus infection causes increased morbidity and mortality in the elderly. Aging impairs the immune response to influenza, both intrinsically and because of altered interactions with endothelial and pulmonary epithelial cells. To characterize these changes, we performed single-cell RNA sequencing (scRNA-seq), spatial transcriptomics, and bulk RNA sequencing (bulk RNA-seq) on lung tissue from young and aged female mice at days 0, 3, and 9 post-influenza infection. Our analyses identified dozens of key genes differentially expressed in kinetic, age-dependent, and cell type-specific manners. Aged immune cells exhibited altered inflammatory, memory, and chemotactic profiles. Aged endothelial cells demonstrated characteristics of reduced vascular wound healing and a prothrombotic state. Spatial transcriptomics identified novel profibrotic and antifibrotic markers expressed by epithelial and non-epithelial cells, highlighting the complex networks that promote fibrosis in aged lungs. Bulk RNA-seq generated a timeline of global transcriptional activity, showing increased expression of genes involved in inflammation and coagulation in aged lungs. Our work provides an atlas of high-throughput sequencing methodologies that can be used to investigate age-related changes in the response to influenza virus, identify novel cell-cell interactions for further study, and ultimately uncover potential therapeutic targets to improve health outcomes in the elderly following influenza infection.
Asunto(s)
Gripe Humana , Infecciones por Orthomyxoviridae , Humanos , Femenino , Animales , Ratones , Anciano , Células Endoteliales , Pulmón/metabolismo , Células Epiteliales/metabolismoRESUMEN
Regulatory T (Treg) cells are inevitable to prevent deleterious immune responses to self and commensal microorganisms. Treg function requires continuous expression of the transcription factor (TF) FOXP3 and is divided into two major subsets: resting (rTregs) and activated (aTregs). Continuous T cell receptor (TCR) signaling plays a vital role in the differentiation of aTregs from their resting state, and in their immune homeostasis. The process by which Tregs differentiate, adapt tissue specificity, and maintain stable phenotypic expression at the transcriptional level is still inconclusivei. In this work, the role of BATF is investigated, which is induced in response to TCR stimulation in naïve T cells and during aTreg differentiation. Mice lacking BATF in Tregs developed multiorgan autoimmune pathology. As a transcriptional regulator, BATF is required for Treg differentiation, homeostasis, and stabilization of FOXP3 expression in different lymphoid and non-lymphoid tissues. Epigenetically, BATF showed direct regulation of Treg-specific genes involved in differentiation, maturation, and tissue accumulation. Most importantly, FOXP3 expression and Treg stability require continuous BATF expression in Tregs, as it regulates demethylation and accessibility of the CNS2 region of the Foxp3 locus. Considering its role in Treg stability, BATF should be considered an important therapeutic target in autoimmune disease.
Asunto(s)
Enfermedades Autoinmunes , Linfocitos T Reguladores , Ratones , Animales , Diferenciación Celular , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismoRESUMEN
Diacylglycerol is a potent element of intracellular secondary signaling cascades whose production is enhanced by cell-surface receptor agonism and function is regulated by enzymatic degradation by diacylglycerol kinases (DGKs). In T cells, stringent regulation of the activity of this second messenger maintains an appropriate balance between effector function and anergy. In this article, we demonstrate that DGKα is an indispensable regulator of TCR-mediated activation of CD8 T cells in lymphocytic choriomeningitis virus Clone 13 viral infection. In the absence of DGKα, Clone 13 infection in a murine model results in a pathologic, proinflammatory state and a multicellular immunopathologic host death that is predominantly driven by CD8 effector T cells.
Asunto(s)
Coriomeningitis Linfocítica , Virus de la Coriomeningitis Linfocítica , Ratones , Animales , Diacilglicerol Quinasa/genética , Diacilglicerol Quinasa/metabolismo , Diglicéridos/metabolismo , Coriomeningitis Linfocítica/metabolismo , Linfocitos T CD8-positivos/metabolismo , Células Clonales , Ratones Endogámicos C57BL , Ratones NoqueadosRESUMEN
Although recent evidence demonstrates heterogeneity among CD8+ T cells during chronic infection, developmental relationships and mechanisms underlying their fate decisions remain incompletely understood. Using single-cell RNA and TCR sequencing, we traced the clonal expansion and differentiation of CD8+ T cells during chronic LCMV infection. We identified immense clonal and phenotypic diversity, including a subset termed intermediate cells. Trajectory analyses and infection models showed intermediate cells arise from progenitor cells before bifurcating into terminal effector and exhausted subsets. Genetic ablation experiments identified that type I IFN drives exhaustion through an IRF7-dependent mechanism, possibly through an IFN-stimulated subset bridging progenitor and exhausted cells. Conversely, Zeb2 was critical for generating effector cells. Intriguingly, some T cell clones exhibited lineage bias. Mechanistically, we identified that TCR avidity correlates with an exhausted fate, whereas SHP-1 selectively restricts low-avidity effector cell accumulation. Thus, our work elucidates novel mechanisms underlying CD8+ T cell fate determination during persistent infection and suggests two potential pathways leading to exhaustion.
Asunto(s)
Linfocitos T CD8-positivos , Infección Persistente , Humanos , Linfocitos T CD8-positivos/metabolismo , Células Cultivadas , Diferenciación Celular , Receptores de Antígenos de Linfocitos T/metabolismoRESUMEN
CD4 T cell help is critical to sustain effector CD8 T cell responses during chronic infection, notably via T follicular helper (Tfh)-derived interleukin-21 (IL-21). Conversely, CD4 depletion results in severe CD8 T cell dysfunction and lifelong viremia despite CD4 T cell reemergence following transient depletion. These observations suggest that repopulating CD4 subsets are functionally or numerically insufficient to orchestrate a robust CD8 response. We utilize spatial transcriptomics and single-cell RNA sequencing (scRNA-seq) to investigate CD4 T cell heterogeneity under CD4-replete and -deplete conditions and explore cellular interactions during chronic infection. Although IL-21-producing Tfh cells repopulate following transient CD4 depletion, they are outnumbered by immunomodulatory CD4 T cells. Moreover, the splenic architecture appears perturbed, with decreases in white pulp regions, coinciding with germinal center losses. These disruptions in splenic architecture are associated with diminished Tfh and progenitor CD8 T cell colocalization, providing a potential mechanism for impaired progenitor-to-effector CD8 T cell differentiation during "un-helped" conditions.
Asunto(s)
Enfermedad Injerto contra Huésped , Virosis , Humanos , Linfocitos T CD4-Positivos , Transcriptoma/genética , Linfocitos T CD8-positivos , Diferenciación CelularRESUMEN
Although recent evidence indicates that CD4+ T cells responding to chronic viral infection are functionally heterogenous, our understanding of the developmental relationships between these subsets, and a determination of how their transcriptional landscape compares to their acute infection counterparts remains unclear. Additionally, whether cell-intrinsic factors such as TCR usage influence CD4+ T cell fate commitment during persistent infection has not previously been studied. Herein, we perform single-cell RNA sequencing (scRNA-seq) combined with single-cell T cell receptor sequencing (scTCR-seq) on virus-specific CD4+ T cells isolated from mice infected with chronic lymphocytic choriomeningitis virus (LCMV) infection. We identify several transcriptionally distinct states among the Th1, Tfh, and memory-like T cell subsets that form at the peak of infection, including the presence of a previously unrecognized Slamf7+ subset with cytolytic features. We further show that the relative distribution of these populations differs substantially between acute and persistent LCMV infection. Moreover, while the progeny of most T cell clones displays membership within each of these transcriptionally unique populations, overall supporting a one cell-multiple fate model, a small fraction of clones display a biased cell fate decision, suggesting that TCR usage may impact CD4+ T cell development during chronic infection. Importantly, comparative analyses further reveal both subset-specific and core gene expression programs that are differentially regulated between CD4+ T cells responding to acute and chronic LCMV infection. Together, these data may serve as a useful framework and allow for a detailed interrogation into the clonal distribution and transcriptional circuits underlying CD4+ T cell differentiation during chronic viral infection.
Asunto(s)
Enfermedad Injerto contra Huésped , Coriomeningitis Linfocítica , Ratones , Animales , Virus de la Coriomeningitis Linfocítica , Ratones Endogámicos C57BL , Coriomeningitis Linfocítica/genética , Receptores de Antígenos de Linfocitos T/genética , Subgrupos de Linfocitos T , Linfocitos T CD4-PositivosRESUMEN
Group 3 innate lymphoid cells (ILC3s) are crucial for the maintenance of host-microbiota homeostasis in gastrointestinal mucosal tissues. The mechanisms that maintain lineage identity of intestinal ILC3s and ILC3-mediated orchestration of microbiota and mucosal T cell immunity are elusive. Here, we identified BATF as a gatekeeper of ILC3 homeostasis in the gut. Depletion of BATF in ILC3s resulted in excessive interferon-γ production, dysbiosis, aberrant T cell immune responses, and spontaneous inflammatory bowel disease (IBD), which was considerably ameliorated by the removal of adaptive immunity, interferon-γ blockade, or antibiotic treatment. Mechanistically, BATF directly binds to the cis-regulatory elements of type 1 effector genes, restrains their chromatin accessibility, and inhibits their expression. Conversely, BATF promotes chromatin accessibility of genes involved in MHCII antigen processing and presentation pathways, which in turn directly promotes the transition of precursor ILC3s to MHCII+ ILC3s. Collectively, our findings reveal that BATF is a key transcription factor for maintaining ILC3 stability and coordinating ILC3-mediated control of intestinal homeostasis.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Inmunidad Innata , Linfocitos , Animales , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Cromatina/metabolismo , Homeostasis , Interferón gamma/metabolismo , Mucosa Intestinal , RatonesRESUMEN
Type 1 diabetes (T1D) is an autoimmune disorder defined by CD8 T cell-mediated destruction of pancreatic ß cells. We have previously shown that diabetogenic CD8 T cells in the islets of non-obese diabetic mice are phenotypically heterogeneous, but clonal heterogeneity remains relatively unexplored. Here, we use paired single-cell RNA and T-cell receptor sequencing (scRNA-seq and scTCR-seq) to characterize autoreactive CD8 T cells from the islets and spleens of non-obese diabetic mice. scTCR-seq demonstrates that CD8 T cells targeting the immunodominant ß-cell epitope IGRP206-214 exhibit restricted TCR gene usage. scRNA-seq identifies six clusters of autoreactive CD8 T cells in the islets and six in the spleen, including memory and exhausted cells. Clonal overlap between IGRP206-214-reactive CD8 T cells in the islets and spleen suggests these cells may circulate between the islets and periphery. Finally, we identify correlations between TCR genes and T-cell clonal expansion and effector fate. Collectively, our work demonstrates that IGRP206-214-specific CD8 T cells are phenotypically heterogeneous but clonally restricted, raising the possibility of selectively targeting these TCR structures for therapeutic benefit.
Asunto(s)
Diabetes Mellitus Experimental , Animales , Linfocitos T CD8-positivos , Diabetes Mellitus Experimental/genética , Genes Codificadores de los Receptores de Linfocitos T , Ratones , Ratones Endogámicos NOD , Ratones Transgénicos , Receptores de Antígenos de Linfocitos T/genéticaRESUMEN
CD4+ T cell-derived interleukin 21 (IL-21) sustains CD8+ T cell responses during chronic viral infection, but the helper subset that confers this protection remains unclear. Here, we applied scRNA and ATAC-seq approaches to determine the heterogeneity of IL-21+CD4+ T cells during LCMV clone 13 infection. CD4+ T cells were comprised of three transcriptionally and epigenetically distinct populations: Cxcr6+ Th1 cells, Cxcr5+ Tfh cells, and a previously unrecognized Slamf6+ memory-like (Tml) subset. T cell differentiation was specifically redirected toward the Tml subset during chronic, but not acute, LCMV infection. Although this subset displayed an enhanced capacity to accumulate and some developmental plasticity, it remained largely quiescent, which may hinder its helper potential. Conversely, mixed bone marrow chimera experiments revealed that Tfh cell-derived IL-21 was critical to sustain CD8+ T cell responses and viral control. Thus, strategies that bolster IL-21+Tfh cell responses may prove effective in enhancing CD8+ T cell-mediated immunity.
Asunto(s)
Células T Auxiliares Foliculares , Virosis , Linfocitos T CD8-positivos , Humanos , InterleucinasRESUMEN
Gastrointestinal (GI) tract involvement is a major determinant for subsequent morbidity and mortality arising during graft-versus-host disease (GVHD). CD4+ T cells that produce granulocyte-macrophage colony stimulating factor (GM-CSF) have emerged as central mediators of inflammation in this tissue site as GM-CSF serves as a critical cytokine link between the adaptive and innate arms of the immune system. However, cellular heterogeneity within the CD4+ GM-CSF+ T-cell population due to the concurrent production of other inflammatory cytokines has raised questions as to whether these cells have a common ontology or if a unique CD4+ GM-CSF+ subset exists that differs from other defined T helper subtypes. Using single-cell RNA sequencing analysis (scRNAseq), we identified two CD4+ GM-CSF+ T-cell populations that arose during GVHD and were distinguishable according to the presence or absence of interferon-γ (IFN-γ) coexpression. CD4+ GM-CSF+ IFN-γ- T cells, which emerged preferentially in the colon, had a distinct transcriptional profile, used unique gene regulatory networks, and possessed a nonoverlapping T-cell receptor repertoire compared with CD4+ GM-CSF+ IFN-γ+ T cells as well as all other transcriptionally defined CD4+ T-cell populations in the colon. Functionally, this CD4+ GM-CSF+ T-cell population contributed to pathologic damage in the GI tract that was critically dependent on signaling through the interleukin-17 (IL-7) receptor but was independent of type 1 interferon signaling. Thus, these studies help to unravel heterogeneity within CD4+ GM-CSF+ T cells that arise during GVHD and define a developmentally distinct colitogenic T helper subtype GM-CSF+ subset that mediates immunopathology.
Asunto(s)
Enfermedad Injerto contra Huésped , Factor Estimulante de Colonias de Granulocitos y Macrófagos , Linfocitos T CD4-Positivos , Linaje de la Célula , Citocinas , Tracto Gastrointestinal , Enfermedad Injerto contra Huésped/etiología , Humanos , Interferón gammaRESUMEN
Activated group 2 innate lymphoid cells (ILC2s) accumulate and promote inflammatory resolution and tissue repair in host defense against acute respiratory viral infections. However, the heterogeneity of ILC2s in the lung and the mechanisms by which ILC2 cells contribute to tissue repair remain elusive. Using single-cell RNA sequencing, we identify a transcriptionally distinct ILC2 subset that showed enrichment for wound healing signature genes and the transcription factor BATF. BATF promotes the proliferation and function of ILC2s and restricts their plasticity during infection with influenza virus. In the absence of BATF, ILC2s lose their immune protective properties and acquire pathogenic ILC3-like functions, leading to persistent neutrophil infiltration, tissue damage, and respiratory failure. Mechanistically, BATF directly binds to the cis-regulatory elements of wound healing genes, maintains their chromatin accessibility, and promotes their expression. Last, BATF plays an important role in an IL-33ST2 feed-forward loop that supports ILC2 cell identity and function. Collectively, our findings shed light on a BATF-dependent ILC2 program, thereby providing a potential therapeutic target for terminating detrimental inflammation during acute viral infection.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/inmunología , Inmunidad Innata/inmunología , Gripe Humana/inmunología , Pulmón/inmunología , Linfocitos/inmunología , Infecciones por Orthomyxoviridae/inmunología , Animales , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/deficiencia , Femenino , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones TransgénicosRESUMEN
While exposure to inflammatory cytokines is thought to contribute to pancreatic ß-cell damage during diabetes, primarily because cytokine-induced nitric oxide impairs ß-cell function and causes cell death with prolonged exposure, we hypothesize that there is a physiological role for cytokine signaling that protects ß-cells from a number of environmental stresses. This hypothesis is derived from the knowledge that ß-cells are essential for survival even though they have a limited capacity to replicate, yet they are exposed to high cytokine levels during infection as most of the pancreatic blood flow is directed to islets. Here, mouse islets were subjected to single-cell RNA sequencing following 18-h cytokine exposure. Treatment with IL-1ß and IFN-γ stimulates expression of inducible nitric oxide synthase (iNOS) mRNA and antiviral and immune-associated genes as well as repression of islet identity factors in a subset of ß- and non-ß-endocrine cells in a nitric oxide-independent manner. Nitric oxide-dependent expression of genes encoding heat shock proteins was observed in both ß- and non-ß-endocrine cells. Interestingly, cells with high expression of heat shock proteins failed to increase antiviral and immune-associated gene expression, suggesting that nitric oxide may be an internal "off switch" to prevent the negative effects of prolonged cytokine signaling in islet endocrine cells. We found no evidence for pro-apoptotic gene expression following 18-h cytokine exposure. Our findings suggest that the primary functions of cytokines and nitric oxide are to protect islet endocrine cells from damage, and only when regulation of cytokine signaling is lost does irreversible damage occur.
Asunto(s)
Citocinas , Óxido Nítrico , Ratones , Animales , Citocinas/genética , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa/genética , Interferón gamma/farmacología , Antivirales , Proteínas de Choque TérmicoRESUMEN
"Stem-like" TCF1+ CD8+ T (TSL) cells are necessary for long-term maintenance of T cell responses and the efficacy of immunotherapy, but, as tumors contain signals that should drive T cell terminal differentiation, how these cells are maintained in tumors remains unclear. In this study, we found that a small number of TCF1+ tumor-specific CD8+ T cells were present in lung tumors throughout their development. Yet, most intratumoral T cells differentiated as tumors progressed, corresponding with an immunologic shift in the tumor microenvironment (TME) from "hot" (T cell inflamed) to "cold" (nonT cell inflamed). By contrast, most tumor-specific CD8+ T cells in tumor-draining lymph nodes (dLNs) had functions and gene expression signatures similar to TSL from chronic lymphocytic choriomeningitis virus infection, and this population was stable over time despite the changes in the TME. dLN T cells were the developmental precursors of, and were clonally related to, their more differentiated intratumoral counterparts. Our data support the hypothesis that dLN T cells are the developmental precursors of the TCF1+ T cells in tumors that are maintained by continuous migration. Last, CD8+ T cells similar to TSL were also present in LNs from patients with lung adenocarcinoma, suggesting that a similar model may be relevant in human disease. Thus, we propose that the dLN TSL reservoir has a critical function in sustaining antitumor T cells during tumor development and in protecting them from the terminal differentiation that occurs in the TME.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Neoplasias Pulmonares/inmunología , Ganglios Linfáticos/inmunología , Animales , Femenino , Inmunoterapia , Neoplasias Pulmonares/terapia , Activación de Linfocitos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Microambiente Tumoral/inmunologíaRESUMEN
In type 1 diabetes (T1D) autoreactive CD8 T cells infiltrate pancreatic islets and destroy insulin-producing ß cells. Progression to T1D onset is a chronic process, which suggests that the effector activity of ß-cell autoreactive CD8 T cells needs to be maintained throughout the course of disease development. The mechanism that sustains diabetogenic CD8 T cell effectors during the course of T1D progression has not been completely defined. Here we used single-cell RNA sequencing to gain further insight into the phenotypic complexity of islet-infiltrating CD8 T cells in NOD mice. We identified two functionally distinct subsets of activated CD8 T cells, CD44highTCF1+CXCR6- and CD44highTCF1-CXCR6+, in islets of prediabetic NOD mice. Compared with CD44highTCF1+CXCR6- CD8 T cells, the CD44highTCF1-CXCR6+ subset expressed higher levels of inhibitory and cytotoxic molecules and was more prone to apoptosis. Adoptive cell transfer experiments revealed that CD44highTCF1+CXCR6- CD8 T cells, through continuous generation of the CD44highTCF1-CXCR6+ subset, were more capable than the latter population to promote insulitis and the development of T1D. We further showed that direct IL-27 signaling in CD8 T cells promoted the generation of terminal effectors from the CD44highTCF1+CXCR6- population. These results indicate that islet CD44highTCF1+CXCR6- CD8 T cells are a progenitor-like subset with self-renewing capacity, and, under an IL-27-controlled mechanism, they differentiate into the CD44highTCF1-CXCR6+ terminal effector population. Our study provides new insight into the sustainability of the CD8 T cell response in the pathogenesis of T1D.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Diabetes Mellitus Tipo 1/inmunología , Interleucina-27/metabolismo , Linfocitos T Citotóxicos/inmunología , Animales , Diferenciación Celular , Autorrenovación de las Células , Células Cultivadas , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Humanos , Células Secretoras de Insulina/inmunología , Ratones , Ratones Endogámicos NODRESUMEN
During acute infections, CD8+ T cells form various memory subpopulations to provide long-lasting protection against reinfection. T central memory (TCM), T effector memory (TEM), and long-lived effector (LLE) cells are circulating memory populations with distinct plasticity, migration patterns, and effector functions. Tissue-resident memory (TRM) cells permanently reside in the frontline sites of pathogen entry and provide tissue-specific protection upon reinfection. Here, using single-cell RNA-sequencing (scRNA-seq) and bulk RNA-seq, we examined the different and shared transcriptomes and regulators of TRM cells with other circulating memory populations. Furthermore, we identified heterogeneity within the TRM pool from small intestine and novel transcriptional regulators that may control the phenotypic and functional heterogeneity of TRM cells during acute infection. Our findings provide a resource for future studies to identify novel pathways for enhancing vaccination and immunotherapeutic approaches.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Perfilación de la Expresión Génica/métodos , Memoria Inmunológica/inmunología , Coriomeningitis Linfocítica/inmunología , Virus de la Coriomeningitis Linfocítica/inmunología , Análisis de la Célula Individual/métodos , Animales , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/virología , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Línea Celular , Células Cultivadas , Femenino , Intestino Delgado/citología , Intestino Delgado/inmunología , Intestino Delgado/virología , Coriomeningitis Linfocítica/patología , Coriomeningitis Linfocítica/virología , Virus de la Coriomeningitis Linfocítica/fisiología , Ratones Endogámicos C57BL , RNA-Seq/métodos , Bazo/citología , Bazo/inmunología , Bazo/virologíaRESUMEN
During chronic viral infection, CD8+ T cells develop into three major phenotypically and functionally distinct subsets: Ly108+TCF-1+ progenitors, Ly108-CX3CR1- terminally exhausted cells and the recently identified CX3CR1+ cytotoxic effector cells. Nevertheless, how CX3CR1+ effector cell differentiation is transcriptionally and epigenetically regulated remains elusive. Here, we identify distinct gene regulatory networks and epigenetic landscapes underpinning the formation of these subsets. Notably, our data demonstrate that CX3CR1+ effector cells bear a striking similarity to short-lived effector cells during acute infection. Genetic deletion of Tbx21 significantly diminished formation of the CX3CR1+ subset. Importantly, we further identify a previously unappreciated role for the transcription factor BATF in maintaining a permissive chromatin structure that allows the transition from TCF-1+ progenitors to CX3CR1+ effector cells. BATF directly bound to regulatory regions near Tbx21 and Klf2, modulating their enhancer accessibility to facilitate the transition. These mechanistic insights can potentially be harnessed to overcome T cell exhaustion during chronic infection and cancer.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/inmunología , Coriomeningitis Linfocítica/inmunología , Proteínas de Dominio T Box/genética , Subgrupos de Linfocitos T/citología , Animales , Antígenos Ly/metabolismo , Receptor 1 de Quimiocinas CX3C/metabolismo , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Línea Celular , Femenino , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Factores de Transcripción de Tipo Kruppel/genética , Virus de la Coriomeningitis Linfocítica/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Subgrupos de Linfocitos T/inmunologíaRESUMEN
BRD4 is a bromodomain-containing protein that binds acetylated histones to regulate transcription. In this issue of JEM, Milner et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20202512) show that BRD4 plays a critical role in the effector function of CD8 T cells responding to infection and cancer.
Asunto(s)
Neoplasias , Proteínas Nucleares , Proteínas de Ciclo Celular/genética , Histonas , Humanos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
The immune response to a chronic viral infection is uniquely tailored to balance viral control and immunopathology. The role of myeloid cells in shaping the response to chronic viral infection, however, is poorly understood. We perform single-cell RNA sequencing of myeloid cells during acute and chronic lymphocytic choriomeningitis virus (LCMV) infection to address this question. Our analysis identifies a cluster of suppressive neutrophils that is enriched in chronic infection. Furthermore, suppressive neutrophils highly express the gene encoding Proviral integration site for Moloney murine leukemia virus-1 (PIM1), a kinase known to promote mitochondrial fitness and cell survival. Pharmacological inhibition of PIM1 selectively diminishes suppressive neutrophil-mediated immunosuppression without affecting the function of monocytic myeloid-derived suppressor cells (M-MDSCs). Decreased accumulation of suppressive neutrophils leads to increased CD8 T cell function and viral control. Mechanistically, PIM kinase activity is required for maintaining fused mitochondrial networks in suppressive neutrophils, but not in M-MDSCs, and loss of PIM kinase function causes increased suppressive neutrophil apoptosis.
Asunto(s)
Neutrófilos/metabolismo , Proteínas Proto-Oncogénicas c-pim-1/metabolismo , Virosis/inmunología , Enfermedad Crónica , HumanosRESUMEN
Exposure to proinflammatory cytokines is believed to contribute to pancreatic ß-cell damage during diabetes development. Although some cytokine-mediated changes in islet gene expression are known, the heterogeneity of the response is not well-understood. After 6-h treatment with IL-1ß and IFN-γ alone or together, mouse islets were subjected to single-cell RNA sequencing. Treatment with both cytokines together led to expression of inducible nitric oxide synthase mRNA (Nos2) and antiviral and immune-associated genes in a subset of ß-cells. Interestingly, IL-1ß alone activated antiviral genes. Subsets of δ- and α-cells expressed Nos2 and exhibited similar gene expression changes as ß-cells, including increased expression of antiviral genes and repression of identity genes. Finally, cytokine responsiveness was inversely correlated with expression of genes encoding heat shock proteins. Our findings show that all islet endocrine cell types respond to cytokines, IL-1ß induces the expression of protective genes, and cellular stress gene expression is associated with inhibition of cytokine signaling.