ABSTRACT
The mechanistic target of rapamycin is an essential regulator of T cell metabolism and differentiation. In this study, we demonstrate that serum- and glucocorticoid-regulated kinase 1 (SGK1), a downstream node of mechanistic target of rapamycin complex 2 signaling, represses memory CD8+ T cell differentiation. During acute infections, murine SGK1-deficient CD8+ T cells adopt an early memory precursor phenotype leading to more long-lived memory T cells. Thus, SGK1-deficient CD8+ T cells demonstrate an enhanced recall capacity in response to reinfection and can readily reject tumors. Mechanistically, activation of SGK1-deficient CD8+ T cells results in decreased Foxo1 phosphorylation and increased nuclear translocation of Foxo1 to promote early memory development. Overall, SGK1 might prove to be a powerful target for enhancing the efficacy of vaccines and tumor immunotherapy.
Subject(s)
CD8-Positive T-Lymphocytes , Mechanistic Target of Rapamycin Complex 2 , Memory T Cells , Protein Serine-Threonine Kinases , Animals , Mice , Cell Differentiation , Immunologic Memory/genetics , Mechanistic Target of Rapamycin Complex 2/metabolism , Multiprotein Complexes/metabolism , Protein Serine-Threonine Kinases/metabolism , Sirolimus , TOR Serine-Threonine Kinases/metabolismABSTRACT
A review of the uses and evidence for the Step-by-Step approach, which identifies febrile infants aged ≤90 days who are at low risk of invasive bacterial infections.
Subject(s)
Bacterial Infections , Infant , Humans , Prospective Studies , Bacterial Infections/diagnosis , Fever/microbiologyABSTRACT
Translocations involving the NUP98 gene produce NUP98-fusion proteins and are associated with a poor prognosis in acute myeloid leukemia (AML). MLL1 is a molecular dependency in NUP98-fusion leukemia, and therefore we investigated the efficacy of therapeutic blockade of the menin-MLL1 interaction in NUP98-fusion leukemia models. Using mouse leukemia cell lines driven by NUP98-HOXA9 and NUP98-JARID1A fusion oncoproteins, we demonstrate that NUP98-fusion-driven leukemia is sensitive to the menin-MLL1 inhibitor VTP50469, with an IC50 similar to what we have previously reported for MLL-rearranged and NPM1c leukemia cells. Menin-MLL1 inhibition upregulates markers of differentiation such as CD11b and downregulates expression of proleukemogenic transcription factors such as Meis1 in NUP98-fusion-transformed leukemia cells. We demonstrate that MLL1 and the NUP98 fusion protein itself are evicted from chromatin at a critical set of genes that are essential for the maintenance of the malignant phenotype. In addition to these in vitro studies, we established patient-derived xenograft (PDX) models of NUP98-fusion-driven AML to test the in vivo efficacy of menin-MLL1 inhibition. Treatment with VTP50469 significantly prolongs survival of mice engrafted with NUP98-NSD1 and NUP98-JARID1A leukemias. Gene expression analysis revealed that menin-MLL1 inhibition simultaneously suppresses a proleukemogenic gene expression program, including downregulation of the HOXa cluster, and upregulates tissue-specific markers of differentiation. These preclinical results suggest that menin-MLL1 inhibition may represent a rational, targeted therapy for patients with NUP98-rearranged leukemias.
Subject(s)
Histone-Lysine N-Methyltransferase/metabolism , Leukemia, Myeloid, Acute/genetics , Myeloid-Lymphoid Leukemia Protein/metabolism , Nuclear Pore Complex Proteins/genetics , Proto-Oncogene Proteins/metabolism , Animals , Cell Line, Tumor , Gene Expression Regulation, Leukemic , Gene Rearrangement , Histone-Lysine N-Methyltransferase/genetics , Leukemia, Myeloid, Acute/metabolism , Mice , Mice, Inbred C57BL , Myeloid-Lymphoid Leukemia Protein/genetics , Nuclear Pore Complex Proteins/metabolism , Oncogene Proteins, Fusion/genetics , Oncogene Proteins, Fusion/metabolism , Protein Interaction Maps , Proto-Oncogene Proteins/geneticsABSTRACT
Higher-order chromatin structure and DNA methylation are implicated in multiple developmental processes, but their relationship to cell state is unknown. Here, we find that large (>7.3 kb) DNA methylation nadirs (termed "grand canyons") can form long loops connecting anchor loci that may be dozens of megabases (Mb) apart, as well as inter-chromosomal links. The interacting loci cover a total of â¼3.5 Mb of the human genome. The strongest interactions are associated with repressive marks made by the Polycomb complex and are diminished upon EZH2 inhibitor treatment. The data are suggestive of the formation of these loops by interactions between repressive elements in the loci, forming a genomic subcompartment, rather than by cohesion/CTCF-mediated extrusion. Interestingly, unlike previously characterized subcompartments, these interactions are present only in particular cell types, such as stem and progenitor cells. Our work reveals that H3K27me3-marked large DNA methylation grand canyons represent a set of very-long-range loops associated with cellular identity.
Subject(s)
Chromatin/chemistry , Chromatin/genetics , DNA Methylation , Hematopoietic Stem Cells/cytology , Hematopoietic Stem Cells/physiology , CCCTC-Binding Factor/genetics , CCCTC-Binding Factor/metabolism , Cell Differentiation , Chromatin/metabolism , Enhancer of Zeste Homolog 2 Protein/genetics , Enhancer of Zeste Homolog 2 Protein/metabolism , Epigenesis, Genetic , Gene Expression Regulation , Histones/genetics , Histones/metabolism , Homeodomain Proteins/genetics , Humans , In Situ Hybridization, Fluorescence , Lysine/genetics , Lysine/metabolism , Nuclear Proteins/genetics , SOXB1 Transcription Factors/genetics , Short Stature Homeobox Protein/genetics , Transcription Factors/geneticsABSTRACT
The Step-by-Step approach to febrile infants identifies febrile infants aged ≤ 90 days who are at low risk for invasive bacterial infections.
Subject(s)
Bacterial Infections/diagnosis , Fever/microbiology , Algorithms , Clinical Decision-Making , Fever/etiology , Humans , Infant , Infant, Newborn , Prospective Studies , Risk AssessmentSubject(s)
High-Throughput Nucleotide Sequencing , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy , Sequence Analysis, DNA , Antineoplastic Agents/therapeutic use , Biomarkers, Tumor/genetics , Child , DNA Mutational Analysis/methods , Genetic Predisposition to Disease , Genetic Variation , Humans , Immunotherapy , Molecular Targeted Therapy , Neoplasm, Residual , Precision Medicine , Precursor Cell Lymphoblastic Leukemia-Lymphoma/diagnosis , Risk AssessmentSubject(s)
Hyperuricemia/history , Hyperuricemia/prevention & control , Precursor Cell Lymphoblastic Leukemia-Lymphoma/history , Precursor Cell Lymphoblastic Leukemia-Lymphoma/prevention & control , Acute Disease , Allopurinol/chemistry , Child , DNA, Neoplasm , History, 20th Century , Humans , Hyperuricemia/therapy , Mercaptopurine/blood , Pediatrics/history , Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy , Tumor Lysis Syndrome , Uric Acid/chemistrySubject(s)
Agammaglobulinemia/diagnosis , Bone Marrow Transplantation , Graft vs Host Reaction , Severe Combined Immunodeficiency/diagnosis , Severe Combined Immunodeficiency/therapy , Stem Cell Transplantation , Agammaglobulinemia/therapy , Diagnosis, Differential , Humans , Infant , Infant, Newborn , Neonatal ScreeningSubject(s)
Antineoplastic Combined Chemotherapy Protocols/history , Leukemia, Myeloid, Acute/history , Precursor Cell Lymphoblastic Leukemia-Lymphoma/history , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Child , History, 20th Century , Humans , Leukemia, Myeloid, Acute/drug therapy , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , United StatesSubject(s)
Adrenal Cortex Neoplasms/genetics , Neoplastic Syndromes, Hereditary/genetics , Pediatrics/history , Adrenal Cortex Neoplasms/complications , Adrenal Cortex Neoplasms/history , Brain Neoplasms/complications , Child , Genetic Predisposition to Disease , History, 20th Century , Humans , Hypertrophy/complications , Mutation , Neoplastic Syndromes, Hereditary/historyABSTRACT
SGK1 is an AGC kinase that regulates the expression of membrane sodium channels in renal tubular cells in a manner dependent on the metabolic checkpoint kinase complex mTORC2. We hypothesized that SGK1 might represent an additional mTORC2-dependent regulator of the differentiation and function of T cells. Here we found that after activation by mTORC2, SGK1 promoted T helper type 2 (TH2) differentiation by negatively regulating degradation of the transcription factor JunB mediated by the E3 ligase Nedd4-2. Simultaneously, SGK1 repressed the production of interferon-γ (IFN-γ) by controlling expression of the long isoform of the transcription factor TCF-1. Consistent with those findings, mice with selective deletion of SGK1 in T cells were resistant to experimentally induced asthma, generated substantial IFN-γ in response to viral infection and more readily rejected tumors.
Subject(s)
Asthma/immunology , Immediate-Early Proteins/metabolism , Melanoma, Experimental/immunology , Multiprotein Complexes/immunology , Poxviridae Infections/immunology , Protein Serine-Threonine Kinases/metabolism , TOR Serine-Threonine Kinases/immunology , Th1 Cells/immunology , Th2 Cells/immunology , Vaccinia virus/immunology , Adaptive Immunity/genetics , Animals , Cell Differentiation/genetics , Cells, Cultured , Endosomal Sorting Complexes Required for Transport/metabolism , Gene Expression Regulation/genetics , Hepatocyte Nuclear Factor 1-alpha , Immediate-Early Proteins/genetics , Interferon-gamma/genetics , Interferon-gamma/metabolism , Mechanistic Target of Rapamycin Complex 2 , Mice , Mice, Inbred C57BL , Mice, Knockout , Nedd4 Ubiquitin Protein Ligases , Protein Serine-Threonine Kinases/genetics , T Cell Transcription Factor 1/genetics , T Cell Transcription Factor 1/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Tumor Burden/genetics , Ubiquitin-Protein Ligases/metabolismABSTRACT
Current models of T-helper-cell differentiation depict the generation of effector cells from a naïve T cell based on the cytokine environment upon T-cell-receptor engagement. We propose a new model of CD4(+) T-cell activation, differentiation, and function whereby the outcome of antigen recognition is dictated by mTOR activity and the subsequent up-regulation of selective metabolic function. Such a model more readily explains the generation of effector and memory cells including the concept of effector and memory Foxp3(+) regulatory cells.
Subject(s)
CD4-Positive T-Lymphocytes/cytology , T-Lymphocytes/cytology , TOR Serine-Threonine Kinases/metabolism , Animals , CD8-Positive T-Lymphocytes/cytology , Cell Differentiation , Cell Lineage , Forkhead Transcription Factors/metabolism , Humans , Immunologic Memory , Lymphocyte Activation , Mice , Mice, Inbred C57BL , Signal Transduction , Up-RegulationABSTRACT
Mounting an adaptive immune response is bioenergetically demanding. As a result, T cell activation coincides with profound changes in cellular metabolism that must be coordinated with instructive signals from cytokine and costimulatory receptors to generate an immune response. Studies examining the intimate link between metabolism and immune function have revealed that different types of T cells have distinct metabolic profiles. Data is emerging that place mTOR, an evolutionarily conserved serine-threonine kinase, as a central integrator of these processes. In this review, we will discuss the role of mTOR in determining both CD4 and CD8 T cell metabolism, differentiation, and trafficking.
Subject(s)
Cell Differentiation/immunology , Lymphocyte Activation/immunology , TOR Serine-Threonine Kinases/metabolism , Animals , Gene Expression Regulation , Humans , Mice , Signal Transduction/immunology , T-Lymphocytes/cytology , T-Lymphocytes/immunology , T-Lymphocytes/metabolismABSTRACT
mTOR is an evolutionarily conserved serine/threonine kinase that plays a central role in integrating environmental cues in the form of growth factors, amino acids, and energy. In the study of the immune system, mTOR is emerging as a critical regulator of immune function because of its role in sensing and integrating cues from the immune microenvironment. With the greater appreciation of cellular metabolism as an important regulator of immune cell function, mTOR is proving to be a vital link between immune function and metabolism. In this review, we discuss the ability of mTOR to direct the adaptive immune response. Specifically, we focus on the role of mTOR in promoting differentiation, activation, and function in T cells, B cells, and antigen-presenting cells.