RESUMEN
In response to acute infection, naive CD4+ T cells primarily differentiate into T helper 1 (Th1) or T follicular helper (Tfh) cells that play critical roles in orchestrating cellular or humoral arms of immunity, respectively. However, despite the well established role of T-bet and BCL-6 in driving Th1 and Tfh cell lineage commitment, respectively, whether additional transcriptional circuits also underlie the fate bifurcation of Th1 and Tfh cell subsets is not fully understood. In this article, we study how the transcriptional regulator Bhlhe40 dictates the Th1/Tfh differentiation axis in mice. CD4+ T cell-specific deletion of Bhlhe40 abrogates Th1 but augments Tfh differentiation. We also assessed an increase in germinal center B cells and Ab production, suggesting that deletion of Bhlhe40 in CD4+ T cells not only alters Tfh differentiation but also their capacity to provide help to B cells. To identify molecular mechanisms by which Bhlhe40 regulates Th1 versus Tfh lineage choice, we first performed epigenetic profiling in the virus specific Th1 and Tfh cells following LCMV infection, which revealed distinct promoter and enhancer activities between the two helper cell lineages. Furthermore, we identified that Bhlhe40 directly binds to cis-regulatory elements of Th1-related genes such as Tbx21 and Cxcr6 to activate their expression while simultaneously binding to regions of Tfh-related genes such as Bcl6 and Cxcr5 to repress their expression. Collectively, our data suggest that Bhlhe40 functions as a transcription activator to promote Th1 cell differentiation and a transcription repressor to suppress Tfh cell differentiation.
Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Diferenciación Celular , Células T Auxiliares Foliculares , Células TH1 , Animales , Ratones , Diferenciación Celular/inmunología , Diferenciación Celular/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Células T Auxiliares Foliculares/inmunología , Células TH1/inmunología , Ratones Noqueados , Ratones Endogámicos C57BL , Linfocitos B/inmunología , Coriomeningitis Linfocítica/inmunología , Coriomeningitis Linfocítica/virología , Centro Germinal/inmunología , Proteínas Proto-Oncogénicas c-bcl-6/genética , Proteínas Proto-Oncogénicas c-bcl-6/metabolismo , Virus de la Coriomeningitis Linfocítica/inmunología , Receptores CXCR5/genética , Receptores CXCR5/metabolismo , Proteínas de HomeodominioRESUMEN
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
During an acute viral infection, CD8 T cells encounter a myriad of antigenic and inflammatory signals of variable strength, which sets off individual T cells on their own differentiation trajectories. However, the developmental path for each of these cells will ultimately lead to one of only two potential outcomes after clearance of the infection-death or survival and development into memory CD8 T cells. How this cell fate decision is made remains incompletely understood. In this study, we explore the transcriptional changes during effector and memory CD8 T cell differentiation at the single-cell level. Using single-cell, transcriptome-derived gene regulatory network analysis, we identified two main groups of regulons that govern this differentiation process. These regulons function in concert with changes in the enhancer landscape to confer the establishment of the regulatory modules underlying the cell fate decision of CD8 T cells. Furthermore, we found that memory precursor effector cells maintain chromatin accessibility at enhancers for key memory-related genes and that these enhancers are highly enriched for E2A binding sites. Finally, we show that E2A directly regulates accessibility of enhancers of many memory-related genes and that its overexpression increases the frequency of memory precursor effector cells and accelerates memory cell formation while decreasing the frequency of short-lived effector cells. Overall, our results suggest that effector and memory CD8 T cell differentiation is largely regulated by two transcriptional circuits, with E2A serving as an important epigenetic regulator of the memory circuit.
Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Linfocitos T CD8-positivos/metabolismo , Memoria Inmunológica/inmunología , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/inmunología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/fisiología , Diferenciación Celular/genética , Cromatina/metabolismo , Epigénesis Genética/genética , Epigenómica/métodos , Femenino , Expresión Génica/genética , Perfilación de la Expresión Génica/métodos , Regulación de la Expresión Génica/genética , Redes Reguladoras de Genes/genética , Hematopoyesis , Humanos , Memoria Inmunológica/genética , Activación de Linfocitos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Análisis de Secuencia de ARN , Análisis de la Célula IndividualRESUMEN
PURPOSE OF REVIEW: As survival rates of those diagnosed with childhood cancer improve over time, the number of long-term survivors continues to grow. Advances have not only been made in the upfront treatment of childhood cancer, but also in the identification and treatment of late complications that may arise as a result of the chemotherapy, radiotherapy, or surgical interventions required to provide a cure. RECENT FINDINGS: As new therapies emerge that are often more targeted to cancerous cells while sparing healthy tissues, the hope is that cure can be achieved without the same long-term side effects for survivors. However, much is unknown regarding how these novel interventions will impact patients in the years to come. It is critical that we continue to follow patients treated with new modalities in order to identify and treat the long-term complications that may arise in future childhood cancer survivors.
Asunto(s)
Supervivientes de Cáncer/estadística & datos numéricos , Enfermedades Cardiovasculares/terapia , Trastornos del Conocimiento/terapia , Enfermedades del Sistema Endocrino/terapia , Neoplasias/complicaciones , Enfermedades Cardiovasculares/etiología , Niño , Trastornos del Conocimiento/etiología , Progresión de la Enfermedad , Enfermedades del Sistema Endocrino/etiología , Humanos , Neoplasias/terapia , Factores de Riesgo , Tasa de SupervivenciaRESUMEN
We have recently encountered a series of cases where an obese caretaker is juxtaposed to a severely starved, malnourished dependent. The cases described all share a common characteristic: that the primary perpetrator was an obese caretaker who tried to exert absolute control over their victim's daily life in a way that included either a severe restriction or complete denial of food. Because the pathophysiology of both child abuse and obesity are incredibly complex and multifactorial, these cases are presented to encourage further discussion and more rigorous investigation into the validity of a hypothesis that has been derived from this set of cases: that the obesity of a child's caretaker may be an additional risk factor for child maltreatment by starvation.
Asunto(s)
Maltrato a los Niños/diagnóstico , Obesidad/psicología , Inanición/etiología , Adolescente , Adulto , Cuidadores/psicología , Maltrato a los Niños/psicología , Preescolar , Femenino , Humanos , Masculino , Factores de RiesgoRESUMEN
Existing literature shows mixed conclusions regarding the impact of ABO incompatibility on outcomes after hematopoietic stem cell transplantation. Because the future for umbilical cord blood (UCB) expansion technologies is bright, we assessed whether this typically overlooked graft characteristic impacted various outcomes after UCB transplantation (UCBT) for nonmalignant disorders (NMDs). A prospectively maintained institutional blood and marrow transplant program database was queried for all patients undergoing first UCBT for NMDs. UCB and recipient ABO compatibility was considered as matched, major mismatched, minor mismatched, or bidirectional mismatched. The impact of ABO incompatibility was assessed on overall survival, graft failure, acute and chronic graft-versus-host disease (GVHD), time to neutrophil and platelet recovery, day 0 to day 100 RBC transfusion burden, and donor hematopoietic chimerism. Through December 2014, 270 patients have undergone first UCBT for various NMDs. In both univariable and multivariable analyses, ABO compatibility status did not appear to impact any outcomes assessed, although a trend toward increased grades III to IV acute GVHD was seen in recipients of major mismatched units. When considering UCBT for treatment of NMDs, ABO compatibility between the donor unit and intended recipient does not appear to be an important consideration in the UCB unit choice.
Asunto(s)
Sistema del Grupo Sanguíneo ABO , Incompatibilidad de Grupos Sanguíneos/complicaciones , Trasplante de Células Madre de Sangre del Cordón Umbilical/efectos adversos , Niño , Preescolar , Trasplante de Células Madre de Sangre del Cordón Umbilical/métodos , Femenino , Supervivencia de Injerto , Enfermedad Injerto contra Huésped/etiología , Humanos , Masculino , Resultado del TratamientoRESUMEN
During chronic viral infection and cancer, it has been established that a subset of progenitor CD8+ T cells continuously gives rise to terminally exhausted cells and cytotoxic effector cells. Although multiple transcriptional programs governing the bifurcated differentiation trajectories have been previously studied, little is known about the chromatin structure changes regulating CD8+ T cell-fate decision. In this study, we demonstrate that the chromatin remodeling complex PBAF restrains expansion and promotes exhaustion of CD8+ T cells during chronic viral infection and cancer. Mechanistically, transcriptomic and epigenomic analyses reveal the role of PBAF in maintaining chromatin accessibility of multiple genetic pathways and transcriptional programs to restrain proliferation and promote T cell exhaustion. Harnessing this knowledge, we demonstrate that perturbation of PBAF complex constrained exhaustion and promoted expansion of tumor-specific CD8+ T cells resulting in antitumor immunity in a preclinical melanoma model, implicating PBAF as an attractive target for cancer immunotherapeutic.
Asunto(s)
Melanoma , Virosis , Humanos , Linfocitos T CD8-positivos , Diferenciación Celular , Melanoma/metabolismo , Infección Persistente , Factores de Transcripción/metabolismo , Virosis/metabolismo , Animales , RatonesRESUMEN
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
In cancer, CD8+ T cells enter a dysfunctional state which prevents them from effectively targeting and killing tumor cells. Tumor-infiltrating CD8+ T cells consist of a heterogeneous population of memory-like progenitor, effector, and terminally exhausted cells that exhibit differing functional and self-renewal capacities. Our recently published work has shown that interleukin (IL)-21-producing CD4+ T cells help to generate effector CD8+ T cells within the tumor, which results in enhanced tumor control. However, the molecular mechanisms by which CD4+ helper T cells regulate the differentiation of effector CD8+ T cells are not well understood. In this study, we found that Basic Leucine Zipper ATF-Like Transcription Factor (BATF), a transcription factor downstream of IL-21 signaling, is critical to maintain CD8+ T cell effector function within the tumor. Using mixed bone marrow chimeras, we demonstrated that CD8+ T cell-specific deletion of BATF resulted in impaired tumor control. In contrast, overexpressing BATF in CD8+ T cells enhanced effector function and resulted in improved tumor control, bypassing the need for CD4+ helper T cells. Transcriptomic analyses revealed that BATF-overexpressing CD8+ T cells had increased expression of costimulatory receptors, effector molecules, and transcriptional regulators, which may contribute to their enhanced activation and effector function. Taken together, our study unravels a previously unappreciated CD4+ T cell-derived IL-21-BATF axis that could provide therapeutic insights to enhance effector CD8+ T cell function to fight cancer.