RESUMEN
Improving effector activity of antigen-specific T cells is a major goal in cancer immunotherapy. Despite the identification of several effector T cell (TEFF)-driving transcription factors (TFs), the transcriptional coordination of TEFF biology remains poorly understood. We developed an in vivo T cell CRISPR screening platform and identified a key mechanism restraining TEFF biology through the ETS family TF, Fli1. Genetic deletion of Fli1 enhanced TEFF responses without compromising memory or exhaustion precursors. Fli1 restrained TEFF lineage differentiation by binding to cis-regulatory elements of effector-associated genes. Loss of Fli1 increased chromatin accessibility at ETS:RUNX motifs, allowing more efficient Runx3-driven TEFF biology. CD8+ T cells lacking Fli1 provided substantially better protection against multiple infections and tumors. These data indicate that Fli1 safeguards the developing CD8+ T cell transcriptional landscape from excessive ETS:RUNX-driven TEFF cell differentiation. Moreover, genetic deletion of Fli1 improves TEFF differentiation and protective immunity in infections and cancer.
Asunto(s)
Linfocitos T CD8-positivos/citología , Proteína Proto-Oncogénica c-fli-1/metabolismo , Animales , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Sistemas CRISPR-Cas , Diferenciación Celular , Enfermedad Crónica , Subunidad alfa 3 del Factor de Unión al Sitio Principal/metabolismo , Epigénesis Genética , Redes Reguladoras de Genes , Infecciones/inmunología , Ratones , Neoplasias/inmunologíaRESUMEN
Exhausted CD8 T cells (TEX) are a distinct state of T cell differentiation associated with failure to clear chronic viruses and cancer. Immunotherapies such as PD-1 blockade can reinvigorate TEX cells, but reinvigoration is not durable. A major unanswered question is whether TEX cells differentiate into functional durable memory T cells (TMEM) upon antigen clearance. Here, using a mouse model, we found that upon eliminating chronic antigenic stimulation, TEX cells partially (re)acquire phenotypic and transcriptional features of TMEM cells. These 'recovering' TEX cells originated from the T cell factor (TCF-1+) TEX progenitor subset. Nevertheless, the recall capacity of these recovering TEX cells remained compromised as compared to TMEM cells. Chromatin-accessibility profiling revealed a failure to recover core memory epigenetic circuits and maintenance of a largely exhausted open chromatin landscape. Thus, despite some phenotypic and transcriptional recovery upon antigen clearance, exhaustion leaves durable epigenetic scars constraining future immune responses. These results support epigenetic remodeling interventions for TEX cell-targeted immunotherapies.
Asunto(s)
Antígenos Virales/inmunología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Memoria Inmunológica/inmunología , Coriomeningitis Linfocítica/inmunología , Animales , Linfocitos T CD8-positivos/citología , Diferenciación Celular/inmunología , Línea Celular , Chlorocebus aethiops , Cricetinae , Epigénesis Genética/genética , Femenino , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Virus de la Coriomeningitis Linfocítica/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Transcripción Genética/genética , Células VeroRESUMEN
Heterogeneity is a hallmark feature of the adaptive immune system in vertebrates. Following infection, naive T cells differentiate into various subsets of effector and memory T cells, which help to eliminate pathogens and maintain long-term immunity. The current model suggests there is a single lineage of naive T cells that give rise to different populations of effector and memory T cells depending on the type and amounts of stimulation they encounter during infection. Here, we have discovered that multiple sub-populations of cells exist in the naive CD8+ T cell pool that are distinguished by their developmental origin, unique transcriptional profiles, distinct chromatin landscapes, and different kinetics and phenotypes after microbial challenge. These data demonstrate that the naive CD8+ T cell pool is not as homogeneous as previously thought and offers a new framework for explaining the remarkable heterogeneity in the effector and memory T cell subsets that arise after infection.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Genes del Desarrollo , Listeria monocytogenes/patogenicidad , Animales , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/metabolismo , Diferenciación Celular , Línea Celular Tumoral , Cromatina/metabolismo , Citocinas/farmacología , Epítopos de Linfocito T/genética , Epítopos de Linfocito T/metabolismo , Memoria Inmunológica , Interferón gamma/metabolismo , Células Asesinas Naturales/citología , Células Asesinas Naturales/metabolismo , Listeria monocytogenes/metabolismo , Ratones , Ratones Endogámicos C57BL , Análisis de Componente Principal , Subgrupos de Linfocitos T/citología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Timo/trasplante , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , TranscriptomaRESUMEN
CD8+ T cell exhaustion is a major barrier to current anti-cancer immunotherapies. Despite this, the developmental biology of exhausted CD8+ T cells (Tex) remains poorly defined, restraining improvement of strategies aimed at "re-invigorating" Tex cells. Here, we defined a four-cell-stage developmental framework for Tex cells. Two TCF1+ progenitor subsets were identified, one tissue restricted and quiescent and one more blood accessible, that gradually lost TCF1 as it divided and converted to a third intermediate Tex subset. This intermediate subset re-engaged some effector biology and increased upon PD-L1 blockade but ultimately converted into a fourth, terminally exhausted subset. By using transcriptional and epigenetic analyses, we identified the control mechanisms underlying subset transitions and defined a key interplay between TCF1, T-bet, and Tox in the process. These data reveal a four-stage developmental hierarchy for Tex cells and define the molecular, transcriptional, and epigenetic mechanisms that could provide opportunities to improve cancer immunotherapy.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Epigénesis Genética/inmunología , Neoplasias/inmunología , Subgrupos de Linfocitos T/inmunología , Transcripción Genética/inmunología , Animales , Antígeno B7-H1/genética , Antígeno B7-H1/inmunología , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/metabolismo , Células Cultivadas , Epigénesis Genética/genética , Factor Nuclear 1-alfa del Hepatocito/genética , Factor Nuclear 1-alfa del Hepatocito/inmunología , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/inmunología , Humanos , Inmunoterapia/métodos , Ratones Endogámicos C57BL , Neoplasias/genética , Neoplasias/terapia , Proteínas de Dominio T Box/genética , Proteínas de Dominio T Box/inmunología , Subgrupos de Linfocitos T/metabolismo , Transcripción Genética/genéticaRESUMEN
CD8 T cells mediate protection against intracellular pathogens and tumors. However, persistent antigen during chronic infections or cancer leads to T cell exhaustion, suboptimal functionality, and reduced protective capacity. Despite considerable work interrogating the transcriptional regulation of exhausted CD8 T cells (TEX), the posttranscriptional control of TEX remains poorly understood. Here, we interrogated the role of microRNAs (miRs) in CD8 T cells responding to acutely resolved or chronic viral infection and identified miR-29a as a key regulator of TEX. Enforced expression of miR-29a improved CD8 T cell responses during chronic viral infection and antagonized exhaustion. miR-29a inhibited exhaustion-driving transcriptional pathways, including inflammatory and T cell receptor signaling, and regulated ribosomal biogenesis. As a result, miR-29a fostered a memory-like CD8 T cell differentiation state during chronic infection. Thus, we identify miR-29a as a key regulator of TEX and define mechanisms by which miR-29a can divert exhaustion toward a more beneficial memory-like CD8 T cell differentiation state.
Asunto(s)
MicroARNs , Neoplasias , Linfocitos T CD8-positivos , Humanos , Inmunoterapia/métodos , MicroARNs/genética , MicroARNs/metabolismo , Neoplasias/metabolismo , Infección PersistenteRESUMEN
CMV is the most common congenital infection in the United States. The major target of congenital CMV is the brain, with clinical manifestations including mental retardation, vision impairment, and sensorineural hearing loss. Previous reports have shown that CD8(+) T cells are required to control viral replication and significant numbers of CMV-specific CD8(+) T cells persist in the brain even after the initial infection has been cleared. However, the dynamics of CD8(+) T cells in the brain during latency remain largely undefined. In this report, we used TCR sequencing to track the development and maintenance of neonatal clonotypes in the brain and spleen of mice during chronic infection. Given the discontinuous nature of tissue-resident memory CD8(+) T cells, we hypothesized that neonatal TCR clonotypes would be locked in the brain and persist into adulthood. Surprisingly, we found that the Ag-specific T cell repertoire in neonatal-infected mice diversified during persistent infection in both the brain and spleen, while maintaining substantial similarity between the CD8(+) T cell populations in the brain and spleen in both early and late infection. However, despite the diversification of, and potential interchange between, the spleen and brain Ag-specific T cell repertoires, we observed that germline-encoded TCR clonotypes, characteristic of neonatal infection, persisted in the brain, albeit sometimes in low abundance. These results provide valuable insights into the evolution of CD8(+) T cell repertoires following neonatal CMV infection and thus have important implications for the development of therapeutic strategies to control CMV in early life.
Asunto(s)
Encéfalo/inmunología , Linfocitos T CD8-positivos/inmunología , Infecciones por Citomegalovirus/inmunología , Memoria Inmunológica , Animales , Animales Recién Nacidos , Citomegalovirus/inmunología , Genes Codificadores de los Receptores de Linfocitos T , Ratones Endogámicos C57BL , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Bazo/citología , Bazo/inmunologíaRESUMEN
Microbial infection during various stages of human development produces widely different clinical outcomes, yet the links between age-related changes in the immune compartment and functional immunity remain unclear. The ability of the immune system to respond to specific antigens and mediate protection in early life is closely correlated with the level of diversification of lymphocyte antigen receptors. We have previously shown that the neonatal primary CD8+ T cell response to replication competent virus is significantly constricted compared to the adult response. In the present study, we have analyzed the subsequent formation of neonatal memory CD8+ T cells and their response to secondary infectious challenge. In particular, we asked whether the less diverse CD8+ T cell clonotypes that are elicited by neonatal vaccination with replication competent virus are 'locked-in' to the adult memory T cell, and thus may compromise the strength of adult immunity. Here we report that neonatal memory CD8+ T cells mediate poor recall responses compared to adults and are comprised of a repertoire of lower avidity T cells. During a later infectious challenge the neonatal memory CD8+ T cells compete poorly with the fully diverse repertoire of naïve adult CD8+ T cells and are outgrown by the adult primary response. This has important implications for the timing of vaccination in early life.
Asunto(s)
Envejecimiento , Linfocitos T CD8-positivos/inmunología , Síndromes de Inmunodeficiencia/etiología , Memoria Inmunológica , Listeriosis/fisiopatología , Modelos Inmunológicos , Vacunas Atenuadas/inmunología , Animales , Animales Recién Nacidos , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/patología , ADN Recombinante/metabolismo , Herpes Simple/inmunología , Herpes Simple/prevención & control , Herpes Simple/virología , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/inmunología , Herpesvirus Humano 1/metabolismo , Sistema Inmunológico/crecimiento & desarrollo , Sistema Inmunológico/inmunología , Sistema Inmunológico/patología , Síndromes de Inmunodeficiencia/inmunología , Síndromes de Inmunodeficiencia/metabolismo , Síndromes de Inmunodeficiencia/patología , Listeria monocytogenes/genética , Listeria monocytogenes/inmunología , Listeria monocytogenes/metabolismo , Listeria monocytogenes/patogenicidad , Listeriosis/inmunología , Listeriosis/microbiología , Listeriosis/prevención & control , Ratones Endogámicos , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Organismos Libres de Patógenos Específicos , Vacunas Atenuadas/efectos adversos , Vaccinia/inmunología , Vaccinia/prevención & control , Vaccinia/virología , Virus Vaccinia/genética , Virus Vaccinia/inmunología , Virus Vaccinia/metabolismo , VirulenciaRESUMEN
CD8+ T cells are classically recognized as adaptive lymphocytes based on their ability to recognize specific foreign antigens and mount memory responses. However, recent studies indicate that some antigen-inexperienced CD8+ T cells can respond to innate cytokines alone in the absence of cognate T cell receptor stimulation, a phenomenon referred to as bystander activation. Here, we demonstrate that neonatal CD8+ T cells undergo a robust and diverse program of bystander activation, which corresponds to enhanced innate-like protection against unrelated pathogens. Using a multi-omics approach, we found that the ability of neonatal CD8+ T cells to respond to innate cytokines derives from their capacity to undergo rapid chromatin remodeling, resulting in the usage of a distinct set of enhancers and transcription factors typically found in innate-like T cells. We observed that the switch between innate and adaptive functions in the CD8+ T cell compartment is mediated by changes in the abundance of distinct subsets of cells. The innate CD8+ T cell subset that predominates in early life was also present in adult mice and humans. Our findings provide support for the layered immune hypothesis and indicate that the CD8+ T cell compartment is more functionally diverse than previously thought.
Asunto(s)
Linfocitos T CD8-positivos , Inmunidad Innata , Humanos , Adulto , Ratones , Animales , Citocinas , Subgrupos de Linfocitos T , AntígenosRESUMEN
The developmental origins of memory T cells remain incompletely understood. During the expansion phase of acute viral infection, we identified a distinct subset of virus-specific CD8+ T cells that possessed distinct characteristics including expression of CD62L, T cell factor 1 (TCF-1), and Eomesodermin; relative quiescence; expression of activation markers; and features of limited effector differentiation. These cells were a quantitatively minor subpopulation of the TCF-1+ pool and exhibited self-renewal, heightened DNA damage surveillance activity, and preferential long-term recall capacity. Despite features of memory and somewhat restrained proliferation during the expansion phase, this subset displayed evidence of stronger TCR signaling than other responding CD8+ T cells, coupled with elevated expression of multiple inhibitory receptors including programmed cell death 1 (PD-1), lymphocyte activating gene 3 (LAG-3), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), CD5, and CD160. Genetic ablation of PD-1 and LAG-3 compromised the formation of this CD62Lhi TCF-1+ subset and subsequent CD8+ T cell memory. Although central memory phenotype CD8+ T cells were formed in the absence of these cells, subsequent memory CD8+ T cell recall responses were compromised. Together, these results identify an important link between genome integrity maintenance and CD8+ T cell memory. Moreover, the data indicate a role for inhibitory receptors in preserving key memory CD8+ T cell precursors during initial activation and differentiation. Identification of this rare subpopulation within the memory CD8+ T cell precursor pool may help reconcile models of the developmental origin of long-term CD8+ T cell memory.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Listeriosis/inmunología , Coriomeningitis Linfocítica/inmunología , Células T de Memoria/inmunología , Células Precursoras de Linfocitos T/inmunología , Animales , Antígenos CD/genética , Linfocitos T CD8-positivos/metabolismo , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Daño del ADN/inmunología , Modelos Animales de Enfermedad , Femenino , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Humanos , Memoria Inmunológica/genética , Listeria monocytogenes/inmunología , Listeriosis/microbiología , Activación de Linfocitos , Coriomeningitis Linfocítica/virología , Virus de la Coriomeningitis Linfocítica/inmunología , Masculino , Células T de Memoria/metabolismo , Ratones , Ratones Noqueados , Células Precursoras de Linfocitos T/metabolismo , Receptor de Muerte Celular Programada 1/genética , Proteína del Gen 3 de Activación de LinfocitosRESUMEN
COVID-19 has become a global pandemic. Immune dysregulation has been implicated, but immune responses remain poorly understood. We analyzed 71 COVID-19 patients compared to recovered and healthy subjects using high dimensional cytometry. Integrated analysis of ~200 immune and >30 clinical features revealed activation of T cell and B cell subsets, but only in some patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses could reach >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable to uninfected subjects. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. These analyses identified three "immunotypes" associated with poor clinical trajectories versus improving health. These immunotypes may have implications for therapeutics and vaccines.
RESUMEN
Coronavirus disease 2019 (COVID-19) is currently a global pandemic, but human immune responses to the virus remain poorly understood. We used high-dimensional cytometry to analyze 125 COVID-19 patients and compare them with recovered and healthy individuals. Integrated analysis of ~200 immune and ~50 clinical features revealed activation of T cell and B cell subsets in a proportion of patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses reaching >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable with that in uninfected individuals. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. Our analyses identified three immunotypes associated with poor clinical trajectories versus improving health. These immunotypes may have implications for the design of therapeutics and vaccines for COVID-19.
Asunto(s)
Linfocitos B/inmunología , Betacoronavirus/inmunología , Infecciones por Coronavirus/inmunología , Neumonía Viral/inmunología , Linfocitos T/inmunología , Inmunidad Adaptativa , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/sangre , Subgrupos de Linfocitos B/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , COVID-19 , Citocinas/sangre , Femenino , Humanos , Memoria Inmunológica , Activación de Linfocitos , Masculino , Persona de Mediana Edad , Pandemias , Células Plasmáticas/inmunología , SARS-CoV-2 , Índice de Severidad de la Enfermedad , Subgrupos de Linfocitos T/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Factores de Tiempo , Adulto JovenRESUMEN
Persistent viral infections and tumors drive development of exhausted T (TEX) cells. In these settings, TEX cells establish an important host-pathogen or host-tumor stalemate. However, TEX cells erode over time, leading to loss of pathogen or cancer containment. We identified microRNA (miR)-155 as a key regulator of sustained TEX cell responses during chronic lymphocytic choriomeningitis virus (LCMV) infection. Genetic deficiency of miR-155 ablated CD8 T cell responses during chronic infection. Conversely, enhanced miR-155 expression promoted expansion and long-term persistence of TEX cells. However, rather than strictly antagonizing exhaustion, miR-155 promoted a terminal TEX cell subset. Transcriptional profiling identified coordinated control of cell signaling and transcription factor pathways, including the key AP-1 family member Fosl2. Overexpression of Fosl2 reversed the miR-155 effects, identifying a link between miR-155 and the AP-1 transcriptional program in regulating TEX cells. Thus, we identify a mechanism of miR-155 regulation of TEX cells and a key role for Fosl2 in T cell exhaustion.