RESUMEN
Adipose tissue group 2 innate lymphoid cells (ILC2s) help maintain metabolic homeostasis by sustaining type 2 immunity and promoting adipose beiging. Although impairment of the ILC2 compartment contributes to obesity-associated insulin resistance, the underlying mechanisms have not been elucidated. Here, we found that ILC2s in obese mice and humans exhibited impaired liver kinase B1 (LKB1) activation. Genetic ablation of LKB1 disrupted ILC2 mitochondrial metabolism and suppressed ILC2 responses, resulting in exacerbated insulin resistance. Mechanistically, LKB1 deficiency induced aberrant PD-1 expression through activation of NFAT, which in turn enhanced mitophagy by suppressing Bcl-xL expression. Blockade of PD-1 restored the normal functions of ILC2s and reversed obesity-induced insulin resistance in mice. Collectively, these data present the LKB1-PD-1 axis as a promising therapeutic target for the treatment of metabolic disease.
Asunto(s)
Tejido Adiposo , Homeostasis , Resistencia a la Insulina , Linfocitos , Mitocondrias , Obesidad , Receptor de Muerte Celular Programada 1 , Proteínas Serina-Treonina Quinasas , Animales , Resistencia a la Insulina/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , Ratones , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Mitocondrias/metabolismo , Humanos , Tejido Adiposo/metabolismo , Tejido Adiposo/inmunología , Obesidad/inmunología , Obesidad/metabolismo , Linfocitos/inmunología , Linfocitos/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Inmunidad Innata , Masculino , Mitofagia/inmunología , Quinasas de la Proteína-Quinasa Activada por el AMPRESUMEN
Group 2 innate lymphoid cells (ILC2s) play crucial roles in mediating allergic inflammation. Recent studies also indicate their involvement in regulating tumor immunity. The tumor suppressor liver kinase B1 (LKB1) inactivating mutations are associated with a variety of human cancers; however, the role of LKB1 in ILC2 function and ILC2-mediated tumor immunity remains unknown. Here, we show that ablation of LKB1 in ILC2s results in an exhausted-like phenotype, which promotes the development of lung melanoma metastasis. Mechanistically, LKB1 deficiency leads to a marked increase in the expression of programmed cell death protein-1 (PD-1) in ILC2s through the activation of the nuclear factor of activated T cell pathway. Blockade of PD-1 can restore the effector functions of LKB1-deficient ILC2s, leading to enhanced antitumor immune responses in vivo. Together, our results reveal that LKB1 acts to restrain the exhausted state of ILC2 to maintain immune homeostasis and antitumor immunity.
Asunto(s)
Proteínas Quinasas Activadas por AMP , Inmunidad Innata , Linfocitos , Ratones Endogámicos C57BL , Proteínas Serina-Treonina Quinasas , Animales , Proteínas Serina-Treonina Quinasas/metabolismo , Ratones , Linfocitos/inmunología , Linfocitos/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/patología , Receptor de Muerte Celular Programada 1/metabolismo , Humanos , Línea Celular Tumoral , Melanoma/inmunología , Melanoma/patologíaRESUMEN
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
Group 3 innate lymphoid cells (ILC3s) play important roles in maintaining intestinal homeostasis by protecting the host from pathogen infections and tissue inflammation. The transcription factor PLZF (promyelocytic leukemia zinc finger), encoded by zinc finger BTB domain containing 16 (Zbtb16), is highly and transiently expressed in ILC precursors (ILCPs). However, the role of PLZF in regulating ILC3 development and function remains unknown. Here, we show that PLZF was specifically expressed in mature intestinal ILC3s compared with other ILC subsets. PLZF was dispensable for ILC3 development. However, PLZF deficiency in ILC3s resulted in increased innate interleukin-22 (IL-22) secretion and protection against gut infection and inflammation. Mechanistically, PLZF negatively regulated IL-22 expression by ILC3s in a cell-intrinsic manner by binding to the IL-22 promoter region for transcriptional repression. Together, our data suggest that PLZF restricts intestinal ILC3 function to regulate gut immune homeostasis.
Asunto(s)
Inmunidad Innata , Linfocitos , Proteína de la Leucemia Promielocítica con Dedos de Zinc , Humanos , Expresión Génica , Inflamación/metabolismo , Factores de Transcripción/metabolismo , Proteína de la Leucemia Promielocítica con Dedos de Zinc/metabolismoRESUMEN
Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) caused by the combination of environmental factors and susceptible genetic background. Experimental autoimmune encephalomyelitis (EAE) is a typical disease model of MS widely used for investigating the pathogenesis in which T lymphocytes specific for myelin antigens initiate an inflammatory reaction in CNS. It is very important to assess how lymphocytes in the CNS regulate the development of disease. However, the approach for measuring the quantity and quality of infiltrated lymphocytes in the CNS is very limited due to the difficulties in isolating and detecting infiltrated lymphocytes from the brain. This manuscript presents a protocol for that is useful for the isolation, identification, and characterization of infiltrated lymphocytes from the CNS and will be helpful for our understanding of how lymphocytes are involved in the development of the CNS autoimmune disease.