1
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Ragupathi A, Kim C, Jacinto E. The mTORC2 signaling network: targets and cross-talks. Biochem J 2024; 481:45-91. [PMID: 38270460 PMCID: PMC10903481 DOI: 10.1042/bcj20220325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/29/2023] [Accepted: 12/18/2023] [Indexed: 01/26/2024]
Abstract
The mechanistic target of rapamycin, mTOR, controls cell metabolism in response to growth signals and stress stimuli. The cellular functions of mTOR are mediated by two distinct protein complexes, mTOR complex 1 (mTORC1) and mTORC2. Rapamycin and its analogs are currently used in the clinic to treat a variety of diseases and have been instrumental in delineating the functions of its direct target, mTORC1. Despite the lack of a specific mTORC2 inhibitor, genetic studies that disrupt mTORC2 expression unravel the functions of this more elusive mTOR complex. Like mTORC1 which responds to growth signals, mTORC2 is also activated by anabolic signals but is additionally triggered by stress. mTORC2 mediates signals from growth factor receptors and G-protein coupled receptors. How stress conditions such as nutrient limitation modulate mTORC2 activation to allow metabolic reprogramming and ensure cell survival remains poorly understood. A variety of downstream effectors of mTORC2 have been identified but the most well-characterized mTORC2 substrates include Akt, PKC, and SGK, which are members of the AGC protein kinase family. Here, we review how mTORC2 is regulated by cellular stimuli including how compartmentalization and modulation of complex components affect mTORC2 signaling. We elaborate on how phosphorylation of its substrates, particularly the AGC kinases, mediates its diverse functions in growth, proliferation, survival, and differentiation. We discuss other signaling and metabolic components that cross-talk with mTORC2 and the cellular output of these signals. Lastly, we consider how to more effectively target the mTORC2 pathway to treat diseases that have deregulated mTOR signaling.
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Affiliation(s)
- Aparna Ragupathi
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Christian Kim
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Estela Jacinto
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
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2
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Werlen G, Li ML, Tottone L, da Silva-Diz V, Su X, Herranz D, Jacinto E. Dietary glucosamine overcomes the defects in αβ-T cell ontogeny caused by the loss of de novo hexosamine biosynthesis. Nat Commun 2022; 13:7404. [PMID: 36456551 PMCID: PMC9715696 DOI: 10.1038/s41467-022-35014-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 11/14/2022] [Indexed: 12/02/2022] Open
Abstract
T cell development requires the coordinated rearrangement of T cell receptor (TCR) gene segments and the expression of either αβ or γδ TCR. However, whether and how de novo synthesis of nutrients contributes to thymocyte commitment to either lineage remains unclear. Here, we find that T cell-specific deficiency in glutamine:fructose-6-phosphate aminotransferase 1 (GFAT1), the rate-limiting enzyme of the de novo hexosamine biosynthesis pathway (dn-HBP), attenuates hexosamine levels, blunts N-glycosylation of TCRβ chains, reduces surface expression of key developmental receptors, thus impairing αβ-T cell ontogeny. GFAT1 deficiency triggers defects in N-glycans, increases the unfolded protein response, and elevates γδ-T cell numbers despite reducing γδ-TCR diversity. Enhancing TCR expression or PI3K/Akt signaling does not reverse developmental defects. Instead, dietary supplementation with the salvage metabolite, glucosamine, and an α-ketoglutarate analogue partially restores αβ-T cell development in GFAT1T-/- mice, while fully rescuing it in ex vivo fetal thymic organ cultures. Thus, dn-HBP fulfils, while salvage nutrients partially satisfy, the elevated demand for hexosamines during early T cell development.
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Affiliation(s)
- Guy Werlen
- grid.430387.b0000 0004 1936 8796Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State Univ. of New Jersey, Piscataway, NJ 08854 USA
| | - Mei-Ling Li
- grid.430387.b0000 0004 1936 8796Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State Univ. of New Jersey, Piscataway, NJ 08854 USA
| | - Luca Tottone
- grid.430387.b0000 0004 1936 8796Dept. of Pharmacology and Pediatrics, Robert Wood Johnson Medical School, and Rutgers Cancer Institute of New Jersey, Rutgers, The State Univ. of New Jersey, New Brunswick, NJ 08901 USA ,grid.26790.3a0000 0004 1936 8606Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, FL Miami, 33136 USA
| | - Victoria da Silva-Diz
- grid.430387.b0000 0004 1936 8796Dept. of Pharmacology and Pediatrics, Robert Wood Johnson Medical School, and Rutgers Cancer Institute of New Jersey, Rutgers, The State Univ. of New Jersey, New Brunswick, NJ 08901 USA
| | - Xiaoyang Su
- grid.430387.b0000 0004 1936 8796Dept. of Medicine, Div. of Endocrinology, Child Health Inst. of New Jersey, Rutgers, The State Univ. of New Jersey, New Brunswick, NJ 08901 USA
| | - Daniel Herranz
- grid.430387.b0000 0004 1936 8796Dept. of Pharmacology and Pediatrics, Robert Wood Johnson Medical School, and Rutgers Cancer Institute of New Jersey, Rutgers, The State Univ. of New Jersey, New Brunswick, NJ 08901 USA
| | - Estela Jacinto
- grid.430387.b0000 0004 1936 8796Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State Univ. of New Jersey, Piscataway, NJ 08854 USA
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3
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Zhang M, Lin X, Yang Z, Li X, Zhou Z, Love PE, Huang J, Zhao B. Metabolic regulation of T cell development. Front Immunol 2022; 13:946119. [PMID: 35958585 PMCID: PMC9357944 DOI: 10.3389/fimmu.2022.946119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/24/2022] [Indexed: 11/24/2022] Open
Abstract
T cell development in the thymus is tightly controlled by complex regulatory mechanisms at multiple checkpoints. Currently, many studies have focused on the transcriptional and posttranslational control of the intrathymic journey of T-cell precursors. However, over the last few years, compelling evidence has highlighted cell metabolism as a critical regulator in this process. Different thymocyte subsets are directed by distinct metabolic pathways and signaling networks to match the specific functional requirements of the stage. Here, we epitomize these metabolic alterations during the development of a T cell and review several recent works that provide insights into equilibrating metabolic quiescence and activation programs. Ultimately, understanding the interplay between cellular metabolism and T cell developmental programs may offer an opportunity to selectively regulate T cell subset functions and to provide potential novel therapeutic approaches to modulate autoimmunity.
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Affiliation(s)
- Mengdi Zhang
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Xiaoxi Lin
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Zhou Yang
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Xia Li
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Zhiguang Zhou
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Paul E. Love
- Section on Hematopoiesis and Lymphocyte Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Jiaqi Huang
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, China
- *Correspondence: Bin Zhao, ; ; Jiaqi Huang, ;;
| | - Bin Zhao
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, China
- *Correspondence: Bin Zhao, ; ; Jiaqi Huang, ;;
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4
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New insights into TCR β-selection. Trends Immunol 2021; 42:735-750. [PMID: 34261578 DOI: 10.1016/j.it.2021.06.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/14/2021] [Accepted: 06/14/2021] [Indexed: 12/12/2022]
Abstract
T cell receptor (TCR) β-selection (herein referred to as β-selection) is a pivotal checkpoint in mammalian T cell development when immature CD4-CD8- T-cells (thymocytes) express pre-TCR following successful Tcrb gene rearrangement. At this stage, αβ T cell lineage commitment and allelic exclusion to restrict one β-chain per cell take place and thymocytes undergo a proliferative burst. β-selection is known to be crucially dependent upon synchronized Notch and pre-TCR signaling; however, other necessary inputs have been identified over the past decade, expanding our knowledge and understanding of the β-selection process. In this review, we discuss recent mechanistic findings that have enabled a more detailed decoding of the molecular dynamics of the β-selection checkpoint and have helped to elucidate its role in early T cell development.
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5
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Werlen G, Jain R, Jacinto E. MTOR Signaling and Metabolism in Early T Cell Development. Genes (Basel) 2021; 12:genes12050728. [PMID: 34068092 PMCID: PMC8152735 DOI: 10.3390/genes12050728] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/10/2021] [Accepted: 05/10/2021] [Indexed: 12/12/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) controls cell fate and responses via its functions in regulating metabolism. Its role in controlling immunity was unraveled by early studies on the immunosuppressive properties of rapamycin. Recent studies have provided insights on how metabolic reprogramming and mTOR signaling impact peripheral T cell activation and fate. The contribution of mTOR and metabolism during early T-cell development in the thymus is also emerging and is the subject of this review. Two major T lineages with distinct immune functions and peripheral homing organs diverge during early thymic development; the αβ- and γδ-T cells, which are defined by their respective TCR subunits. Thymic T-regulatory cells, which have immunosuppressive functions, also develop in the thymus from positively selected αβ-T cells. Here, we review recent findings on how the two mTOR protein complexes, mTORC1 and mTORC2, and the signaling molecules involved in the mTOR pathway are involved in thymocyte differentiation. We discuss emerging views on how metabolic remodeling impacts early T cell development and how this can be mediated via mTOR signaling.
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6
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Chou PC, Rajput S, Zhao X, Patel C, Albaciete D, Oh WJ, Daguplo HQ, Patel N, Su B, Werlen G, Jacinto E. mTORC2 Is Involved in the Induction of RSK Phosphorylation by Serum or Nutrient Starvation. Cells 2020; 9:E1567. [PMID: 32605013 PMCID: PMC7408474 DOI: 10.3390/cells9071567] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/17/2020] [Accepted: 06/23/2020] [Indexed: 12/26/2022] Open
Abstract
Cells adjust to nutrient fluctuations to restore metabolic homeostasis. The mechanistic target of rapamycin (mTOR) complex 2 responds to nutrient levels and growth signals to phosphorylate protein kinases belonging to the AGC (Protein Kinases A,G,C) family such as Akt and PKC. Phosphorylation of these AGC kinases at their conserved hydrophobic motif (HM) site by mTORC2 enhances their activation and mediates the functions of mTORC2 in cell growth and metabolism. Another AGC kinase family member that is known to undergo increased phosphorylation at the homologous HM site (Ser380) is the p90 ribosomal S6 kinase (RSK). Phosphorylation at Ser380 is facilitated by the activation of the mitogen-activated protein kinase/extracellular signal regulated kinase (MAPK/ERK) in response to growth factor stimulation. Here, we demonstrate that optimal phosphorylation of RSK at this site requires an intact mTORC2. We also found that RSK is robustly phosphorylated at Ser380 upon nutrient withdrawal or inhibition of glycolysis, conditions that increase mTORC2 activation. However, pharmacological inhibition of mTOR did not abolish RSK phosphorylation at Ser380, indicating that mTOR catalytic activity is not required for this phosphorylation. Since RSK and SIN1β colocalize at the membrane during serum restimulation and acute glutamine withdrawal, mTORC2 could act as a scaffold to enhance RSK HM site phosphorylation. Among the known RSK substrates, the CCTβ subunit of the chaperonin containing TCP-1 (CCT) complex had defective phosphorylation in the absence of mTORC2. Our findings indicate that the mTORC2-mediated phosphorylation of the RSK HM site could confer RSK substrate specificity and reveal that RSK responds to nutrient fluctuations.
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Affiliation(s)
- Po-Chien Chou
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (P.-C.C.); (S.R.); (C.P.); (D.A.); (W.J.O.); (H.Q.D.); (N.P.); (G.W.)
| | - Swati Rajput
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (P.-C.C.); (S.R.); (C.P.); (D.A.); (W.J.O.); (H.Q.D.); (N.P.); (G.W.)
| | - Xiaoyun Zhao
- Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200240, China; (X.Z.); (B.S.)
| | - Chadni Patel
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (P.-C.C.); (S.R.); (C.P.); (D.A.); (W.J.O.); (H.Q.D.); (N.P.); (G.W.)
| | - Danielle Albaciete
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (P.-C.C.); (S.R.); (C.P.); (D.A.); (W.J.O.); (H.Q.D.); (N.P.); (G.W.)
| | - Won Jun Oh
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (P.-C.C.); (S.R.); (C.P.); (D.A.); (W.J.O.); (H.Q.D.); (N.P.); (G.W.)
| | - Heineken Queen Daguplo
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (P.-C.C.); (S.R.); (C.P.); (D.A.); (W.J.O.); (H.Q.D.); (N.P.); (G.W.)
| | - Nikhil Patel
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (P.-C.C.); (S.R.); (C.P.); (D.A.); (W.J.O.); (H.Q.D.); (N.P.); (G.W.)
| | - Bing Su
- Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200240, China; (X.Z.); (B.S.)
| | - Guy Werlen
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (P.-C.C.); (S.R.); (C.P.); (D.A.); (W.J.O.); (H.Q.D.); (N.P.); (G.W.)
| | - Estela Jacinto
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (P.-C.C.); (S.R.); (C.P.); (D.A.); (W.J.O.); (H.Q.D.); (N.P.); (G.W.)
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7
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Huang H, Long L, Zhou P, Chapman NM, Chi H. mTOR signaling at the crossroads of environmental signals and T-cell fate decisions. Immunol Rev 2020; 295:15-38. [PMID: 32212344 PMCID: PMC8101438 DOI: 10.1111/imr.12845] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/19/2020] [Indexed: 12/28/2022]
Abstract
The evolutionarily conserved serine/threonine kinase mTOR (mechanistic target of rapamycin) forms the distinct protein complexes mTORC1 and mTORC2 and integrates signals from the environment to coordinate downstream signaling events and various cellular processes. T cells rely on mTOR activity for their development and to establish their homeostasis and functional fitness. Here, we review recent progress in our understanding of the upstream signaling and downstream targets of mTOR. We also provide an updated overview of the roles of mTOR in T-cell development, homeostasis, activation, and effector-cell fate decisions, as well as its important impacts on the suppressive activity of regulatory T cells. Moreover, we summarize the emerging roles of mTOR in T-cell exhaustion and transdifferentiation. A better understanding of the contribution of mTOR to T-cell fate decisions will ultimately aid in the therapeutic targeting of mTOR in human disease.
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Affiliation(s)
- Hongling Huang
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Lingyun Long
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
- Equal contribution
| | - Peipei Zhou
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
- Equal contribution
| | - Nicole M. Chapman
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Hongbo Chi
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
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8
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Ruan C, Ouyang X, Liu H, Li S, Jin J, Tang W, Xia Y, Su B. Sin1-mediated mTOR signaling in cell growth, metabolism and immune response. Natl Sci Rev 2019; 6:1149-1162. [PMID: 34691993 PMCID: PMC8291397 DOI: 10.1093/nsr/nwz171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/22/2019] [Accepted: 10/22/2019] [Indexed: 12/22/2022] Open
Abstract
Abstract
The mammalian target of rapamycin (mTOR) is an evolutionarily conserved Ser/Thr protein kinase with essential cellular function via processing various extracellular and intracellular inputs. Two distinct multi-protein mTOR complexes (mTORC), mTORC1 and mTORC2, have been identified and well characterized in eukaryotic cells from yeast to human. Sin1, which stands for Sty1/Spc1-interacting protein1, also known as mitogen-activated protein kinase (MAPK) associated protein (MAPKAP)1, is an evolutionarily conserved adaptor protein. Mammalian Sin1 interacts with many cellular proteins, but it has been widely studied as an essential component of mTORC2, and it is crucial not only for the assembly of mTORC2 but also for the regulation of its substrate specificity. In this review, we summarize our current knowledge of the structure and functions of Sin1, focusing specifically on its protein interaction network and its roles in the mTOR pathway that could account for various cellular functions of mTOR in growth, metabolism, immunity and cancer.
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Affiliation(s)
- Chun Ruan
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xinxing Ouyang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Hongzhi Liu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Song Li
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jingsi Jin
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Weiyi Tang
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yu Xia
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bing Su
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
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9
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Ouyang X, Han Y, Qu G, Li M, Wu N, Liu H, Arojo O, Sun H, Liu X, Liu D, Chen L, Zou Q, Su B. Metabolic regulation of T cell development by Sin1-mTORC2 is mediated by pyruvate kinase M2. J Mol Cell Biol 2019; 11:93-106. [PMID: 30428057 PMCID: PMC6392101 DOI: 10.1093/jmcb/mjy065] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 10/16/2018] [Accepted: 11/13/2018] [Indexed: 12/16/2022] Open
Abstract
Glucose metabolism plays a key role in thymocyte development. The mammalian target of rapamycin complex 2 (mTORC2) is a critical regulator of cell growth and metabolism, but its role in early thymocyte development and metabolism has not been fully studied. We show here that genetic ablation of Sin1, an essential component of mTORC2, in T lineage cells results in severely impaired thymocyte development at the CD4-CD8- double negative (DN) stages but not at the CD4+CD8+ double positive (DP) or later stages. Notably, Sin1-deficient DN thymocytes show markedly reduced proliferation and glycolysis. Importantly, we discover that the M2 isoform of pyruvate kinase (PKM2) is a novel and crucial Sin1 effector in promoting DN thymocyte development and metabolism. At the molecular level, we show that Sin1-mTORC2 controls PKM2 expression through an AKT-dependent PPAR-γ nuclear translocation. Together, our study unravels a novel mTORC2-PPAR-γ-PKM2 pathway in immune-metabolic regulation of early thymocyte development.
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Affiliation(s)
- Xinxing Ouyang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuheng Han
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Guojun Qu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Man Li
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ningbo Wu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hongzhi Liu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Omotooke Arojo
- Department of Immunobiology and the Vascular Biology and Therapeutics Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Hongxiang Sun
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaobo Liu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Dou Liu
- Department of Immunobiology and the Vascular Biology and Therapeutics Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Lei Chen
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiang Zou
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bing Su
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Immunobiology and the Vascular Biology and Therapeutics Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
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10
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Chi H. Sin1-mTORC2 signaling drives glycolysis of developing thymocytes. J Mol Cell Biol 2019; 11:91-92. [PMID: 30496428 PMCID: PMC6392098 DOI: 10.1093/jmcb/mjy078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 11/26/2018] [Indexed: 11/18/2022] Open
Affiliation(s)
- Hongbo Chi
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, USA
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11
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Who does TORC2 talk to? Biochem J 2018; 475:1721-1738. [PMID: 29794170 DOI: 10.1042/bcj20180130] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 04/19/2018] [Accepted: 04/23/2018] [Indexed: 12/21/2022]
Abstract
The target of rapamycin (TOR) is a protein kinase that, by forming complexes with partner proteins, governs diverse cellular signalling networks to regulate a wide range of processes. TOR thus plays central roles in maintaining normal cellular functions and, when dysregulated, in diverse diseases. TOR forms two distinct types of multiprotein complexes (TOR complexes 1 and 2, TORC1 and TORC2). TORC1 and TORC2 differ in their composition, their control and their substrates, so that they play quite distinct roles in cellular physiology. Much effort has been focused on deciphering the detailed regulatory links within the TOR pathways and the structure and control of TOR complexes. In this review, we summarize recent advances in understanding mammalian (m) TORC2, its structure, its regulation, and its substrates, which link TORC2 signalling to the control of cell functions. It is now clear that TORC2 regulates several aspects of cell metabolism, including lipogenesis and glucose transport. It also regulates gene transcription, the cytoskeleton, and the activity of a subset of other protein kinases.
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12
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Li Q, Liu P, Xuan X, Zhang J, Zhang Y, Zhu Z, Gao F, Zhang Q, Du Y. CCR9 AND CCR7 are overexpressed in CD4 - CD8 - thymocytes of myasthenia gravis patients. Muscle Nerve 2016; 55:84-90. [PMID: 26616645 DOI: 10.1002/mus.24999] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/25/2015] [Accepted: 11/25/2015] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Chemokine CC motif receptors 9 and 7 (CCR9 and CCR7) play a major role in the migration of T-cell precursors to the thymus to initiate T thymopoiesis. However, their role in development of T-cells in myasthenia gravis (MG) patients has not been fully elucidated. METHODS Expression and distribution of CCR9+ and CCR7+ cells were detected by flow cytometry and immunofluorescence. Real-time polymerase chain reaction was used to check the adhesion molecules on CD4- CD8- double-negative (DN) thymocytes. RESULTS CCR9 and CCR7 expression by DN thymocytes increased in the MG thymus; the levels of CCR9, CCR7, interleukin-7R mRNA increased, and CXCR4 levels decreased compared with levels in the non-MG thymus. More CCR7 and CCR9 double-positive (DP) thymocytes were gathered near the subcapsular region in MG thymus. CONCLUSIONS Enhanced expression of CCR9 and CCR7 may complicate the differentiation of DP thymocytes from the DN stage in MG thymus. Muscle Nerve, 2016 Muscle Nerve 55: 84-90, 2017.
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Affiliation(s)
- Qianru Li
- Department of Immunology, Basic Medical College, Zhengzhou University, No.100 of Science Road, Zhengzhou 450001, Henan Province, PR China
| | - Pingping Liu
- Department of Immunology, Basic Medical College, Zhengzhou University, No.100 of Science Road, Zhengzhou 450001, Henan Province, PR China
| | - Xiaoyan Xuan
- Department of Immunology, Basic Medical College, Zhengzhou University, No.100 of Science Road, Zhengzhou 450001, Henan Province, PR China
| | - Junfeng Zhang
- Department of Laboratory, the Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, PR China
| | - Yun Zhang
- Department of Immunology, Basic Medical College, Zhengzhou University, No.100 of Science Road, Zhengzhou 450001, Henan Province, PR China
| | - Zhengkun Zhu
- Department of Immunology, Basic Medical College, Zhengzhou University, No.100 of Science Road, Zhengzhou 450001, Henan Province, PR China
| | - Feng Gao
- Henan Institute of Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, PR China
| | - Qingyong Zhang
- The Second Affiliated Hospital, Zhengzhou University, Zhengzhou, Henan Province, PR China
| | - Ying Du
- Department of Immunology, Basic Medical College, Zhengzhou University, No.100 of Science Road, Zhengzhou 450001, Henan Province, PR China
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13
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Lin X, Yang J, Wang J, Huang H, Wang HX, Chen P, Wang S, Pan Y, Qiu YR, Taylor GA, Vallance BA, Gao J, Zhong XP. mTOR is critical for intestinal T-cell homeostasis and resistance to Citrobacter rodentium. Sci Rep 2016; 6:34939. [PMID: 27731345 PMCID: PMC5059740 DOI: 10.1038/srep34939] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 09/20/2016] [Indexed: 11/25/2022] Open
Abstract
T-cells play an important role in promoting mucosal immunity against pathogens, but the mechanistic basis for their homeostasis in the intestine is still poorly understood. We report here that T-cell-specific deletion of mTOR results in dramatically decreased CD4 and CD8 T-cell numbers in the lamina propria of both small and large intestines under both steady-state and inflammatory conditions. These defects result in defective host resistance against a murine enteropathogen, Citrobacter rodentium, leading to the death of the animals. We further demonstrated that mTOR deficiency reduces the generation of gut-homing effector T-cells in both mesenteric lymph nodes and Peyer’s patches without obviously affecting expression of gut-homing molecules on those effector T-cells. Using mice with T-cell-specific ablation of Raptor/mTORC1 or Rictor/mTORC2, we revealed that both mTORC1 and, to a lesser extent, mTORC2 contribute to both CD4 and CD8 T-cell accumulation in the gastrointestinal (GI) tract. Additionally, mTORC1 but not mTORC2 plays an important role regulating the proliferative renewal of both CD4 and CD8 T-cells in the intestines. Our data thus reveal that mTOR is crucial for T-cell accumulation in the GI tract and for establishing local adaptive immunity against pathogens.
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Affiliation(s)
- Xingguang Lin
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, NC 27710, USA.,School of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Jialong Yang
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, NC 27710, USA
| | - Jinli Wang
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, NC 27710, USA.,School of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Hongxiang Huang
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, NC 27710, USA.,Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Hong-Xia Wang
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, NC 27710, USA.,Laboratory Medicine Center, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Pengcheng Chen
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, NC 27710, USA.,School of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Shang Wang
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, NC 27710, USA.,School of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yun Pan
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, NC 27710, USA.,School of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yu-Rong Qiu
- Laboratory Medicine Center, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Gregory A Taylor
- Geriatric Research, Education, and Clinical Center, VA Medical Center, Durham, NC 27705, USA.,Department of Medicine, Division of Geriatrics, and Center for the Study of Aging and Human Development, Duke University Medical Center, Durham NC 27710, USA.,Department of Molecular Genetics and Microbiology Duke University Medical Center, Durham NC 27710, USA
| | - Bruce A Vallance
- Division of Gastroenterology, Department of Pediatrics, Child and Family Research Institute and the University of British Columbia, Vancouver, British Columbia V6H 3V4, Canada
| | - Jimin Gao
- School of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Xiao-Ping Zhong
- Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, Durham, NC 27710, USA.,Department of Immunology, Medical Center, Durham, NC 27710, USA.,Hematologic Malignancies and Cellular Therapies Program, Duke Cancer Institute, Duke University Medical Center, Durham, NC 27710, USA
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14
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mTORC2 Responds to Glutamine Catabolite Levels to Modulate the Hexosamine Biosynthesis Enzyme GFAT1. Mol Cell 2016; 63:811-26. [PMID: 27570073 DOI: 10.1016/j.molcel.2016.07.015] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/24/2016] [Accepted: 07/19/2016] [Indexed: 12/28/2022]
Abstract
Highly proliferating cells are particularly dependent on glucose and glutamine for bioenergetics and macromolecule biosynthesis. The signals that respond to nutrient fluctuations to maintain metabolic homeostasis remain poorly understood. Here, we found that mTORC2 is activated by nutrient deprivation due to decreasing glutamine catabolites. We elucidate how mTORC2 modulates a glutamine-requiring biosynthetic pathway, the hexosamine biosynthesis pathway (HBP) via regulation of expression of glutamine:fructose-6-phosphate amidotransferase 1 (GFAT1), the rate-limiting enzyme of the HBP. GFAT1 expression is dependent on sufficient amounts of glutaminolysis catabolites particularly α-ketoglutarate, which are generated in an mTORC2-dependent manner. Additionally, mTORC2 is essential for proper expression and nuclear accumulation of the GFAT1 transcriptional regulator, Xbp1s. Thus, while mTORC1 senses amino acid abundance to promote anabolism, mTORC2 responds to declining glutamine catabolites in order to restore metabolic homeostasis. Our findings uncover the role of mTORC2 in metabolic reprogramming and have implications for understanding insulin resistance and tumorigenesis.
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15
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Gaubitz C, Prouteau M, Kusmider B, Loewith R. TORC2 Structure and Function. Trends Biochem Sci 2016; 41:532-545. [PMID: 27161823 DOI: 10.1016/j.tibs.2016.04.001] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/30/2016] [Accepted: 04/05/2016] [Indexed: 12/21/2022]
Abstract
The target of rapamycin (TOR) kinase functions in two multiprotein complexes, TORC1 and TORC2. Although both complexes are evolutionarily conserved, only TORC1 is acutely inhibited by rapamycin. Consequently, only TORC1 signaling is relatively well understood; and, at present, only mammalian TORC1 is a validated drug target, pursued in immunosuppression and oncology. However, the knowledge void surrounding TORC2 is dissipating. Acute inhibition of TORC2 with small molecules is now possible and structural studies of both TORC1 and TORC2 have recently been reported. Here we review these recent advances as well as observations made from tissue-specific mTORC2 knockout mice. Together these studies help define TORC2 structure-function relationships and suggest that mammalian TORC2 may one day also become a bona fide clinical target.
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Affiliation(s)
- Christl Gaubitz
- Department of Molecular Biology, and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest Ansermet, CH1211 Geneva, Switzerland
| | - Manoel Prouteau
- Department of Molecular Biology, and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest Ansermet, CH1211 Geneva, Switzerland
| | - Beata Kusmider
- Department of Molecular Biology, and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest Ansermet, CH1211 Geneva, Switzerland
| | - Robbie Loewith
- Department of Molecular Biology, and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest Ansermet, CH1211 Geneva, Switzerland; National Centre of Competence in Research "Chemical Biology", University of Geneva, Geneva CH-1211, Switzerland.
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16
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Waldner M, Fantus D, Solari M, Thomson AW. New perspectives on mTOR inhibitors (rapamycin, rapalogs and TORKinibs) in transplantation. Br J Clin Pharmacol 2016; 82:1158-1170. [PMID: 26810941 DOI: 10.1111/bcp.12893] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/22/2016] [Accepted: 01/25/2016] [Indexed: 02/06/2023] Open
Abstract
The macrolide rapamycin and its analogues (rapalogs) constitute the first generation of mammalian target of rapamycin (mTOR) inhibitors. Since the introduction of rapamycin as an immunosuppressant, there has been extensive progress in understanding its complex mechanisms of action. New insights into the function of mTOR in different immune cell types, vascular endothelial cells and neoplastic cells have opened new opportunities and challenges regarding mTOR as a pharmacological target. Currently, the two known mTOR complexes, mTOR complex (mTORC) 1 and mTORC2, are the subject of intense investigation, and the introduction of second-generation dual mTORC kinase inhibitors (TORKinibs) and gene knockout mice is helping to uncover the distinct roles of these complexes in different cell types. While the pharmacological profiling of rapalogs is advanced, much less is known about the properties of TORKinibs. A potential benefit of mTOR inhibition in transplantation is improved protection against transplant-associated viral infections compared with standard calcineurin inhibitor-based immunosuppression. Preclinical and clinical data also underscore the potentially favourable antitumour effects of mTOR inhibitors in regard to transplant-associated malignancies and as a novel treatment option for various other cancers. Many aspects of the mechanisms of action of mTOR inhibitors and their clinical implications remain unknown. In this brief review we discuss new findings and perspectives of mTOR inhibitors in transplantation.
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Affiliation(s)
- Matthias Waldner
- Department of Plastic Surgery, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Plastic Surgery, University of Zurich, Zurich, Switzerland
| | - Daniel Fantus
- Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mario Solari
- Department of Plastic Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Angus W Thomson
- Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA. .,Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA.
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17
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Westernberg L, Conche C, Huang YH, Rigaud S, Deng Y, Siegemund S, Mukherjee S, Nosaka L, Das J, Sauer K. Non-canonical antagonism of PI3K by the kinase Itpkb delays thymocyte β-selection and renders it Notch-dependent. eLife 2016; 5. [PMID: 26880557 PMCID: PMC4764578 DOI: 10.7554/elife.10786] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 01/08/2016] [Indexed: 12/22/2022] Open
Abstract
β-selection is the most pivotal event determining αβ T cell fate. Here, surface-expression of a pre-T cell receptor (pre-TCR) induces thymocyte metabolic activation, proliferation, survival and differentiation. Besides the pre-TCR, β-selection also requires co-stimulatory signals from Notch receptors - key cell fate determinants in eukaryotes. Here, we show that this Notch-dependence is established through antagonistic signaling by the pre-TCR/Notch effector, phosphoinositide 3-kinase (PI3K), and by inositol-trisphosphate 3-kinase B (Itpkb). Canonically, PI3K is counteracted by the lipid-phosphatases Pten and Inpp5d/SHIP-1. In contrast, Itpkb dampens pre-TCR induced PI3K/Akt signaling by producing IP4, a soluble antagonist of the Akt-activating PI3K-product PIP3. Itpkb-/- thymocytes are pre-TCR hyperresponsive, hyperactivate Akt, downstream mTOR and metabolism, undergo an accelerated β-selection and can develop to CD4+CD8+ cells without Notch. This is reversed by inhibition of Akt, mTOR or glucose metabolism. Thus, non-canonical PI3K-antagonism by Itpkb restricts pre-TCR induced metabolic activation to enforce coincidence-detection of pre-TCR expression and Notch-engagement. DOI:http://dx.doi.org/10.7554/eLife.10786.001 T cells defend our body against cancer and infectious agents such as viruses. However, they can also cause rheumatoid arthritis and other autoimmune diseases by attacking healthy tissue. T cells recognize target cells via receptor proteins on their surface. To maximize the variety of infections and cancers our immune system can recognize, we generate millions of T cells with different T cell receptors every day. To ensure T cells work correctly, T cell receptors are tested at various checkpoints. The first checkpoint involves a process called beta (β) selection, during which T cells produce their first T cell receptor – the so-called pre-T cell receptor. This receptor causes T cells to divide and mature, and sets their future identity or “fate”. To complete β-selection, T cells must also receive signals from another surface receptor – one that belongs to the Notch family, which determines cell fate in many different tissues. The Notch receptor and the pre-T cell receptor both activate an enzyme called PI3K – a key mediator of β-selection. But the pre-T cell receptor also activates another enzyme called Itpkb that is required for T cell development. Westernberg, Conche et al. have now investigated how these different proteins and signaling processes work and interact during β-selection, using mice that lack several immune genes, including the gene that produces Itpkb. The results of the experiments show that during β-selection, Itpkb limits the ability of PI3K to activate some of its key target proteins. This “dampened” PI3K signaling ensures that both the pre-T cell receptor and the Notch receptor must be activated to trigger T cell maturation. Without Itpkb, β-selection can occur in the absence of Notch signaling. As Notch signaling is important for determining the fate of many different cell types, Westernberg, Conche et al.’s findings raise the possibility that Itpkb might also regulate cell fate determination in other tissues. Moreover, Itpkb may suppress tumor development, because excessive PI3K signaling drives many cancers. DOI:http://dx.doi.org/10.7554/eLife.10786.002
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Affiliation(s)
- Luise Westernberg
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, United States
| | - Claire Conche
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, United States
| | - Yina Hsing Huang
- Department of Pathology, Geisel School of Medicine, Lebanon, United States.,Departments of Microbiology and Immunology, Geisel School of Medicine, Lebanon, United States
| | - Stephanie Rigaud
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, United States
| | - Yisong Deng
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, United States
| | - Sabine Siegemund
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, United States
| | - Sayak Mukherjee
- Department of Pediatrics, The Ohio State University, Columbus, United States.,Department of Physics, The Ohio State University, Columbus, United States.,Battelle Center for Mathematical Medicine, The Ohio State University, Columbus, United States
| | - Lyn'Al Nosaka
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, United States
| | - Jayajit Das
- Department of Pediatrics, The Ohio State University, Columbus, United States.,Department of Physics, The Ohio State University, Columbus, United States.,Battelle Center for Mathematical Medicine, The Ohio State University, Columbus, United States
| | - Karsten Sauer
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, United States.,Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, United States
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18
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Herek TA, Shew TD, Spurgin HN, Cutucache CE. Conserved Molecular Underpinnings and Characterization of a Role for Caveolin-1 in the Tumor Microenvironment of Mature T-Cell Lymphomas. PLoS One 2015; 10:e0142682. [PMID: 26566034 PMCID: PMC4643970 DOI: 10.1371/journal.pone.0142682] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 10/26/2015] [Indexed: 12/02/2022] Open
Abstract
Neoplasms of extra-thymic T-cell origin represent a rare and difficult population characterized by poor clinical outcome, aggressive presentation, and poorly defined molecular characteristics. Much work has been done to gain greater insights into distinguishing features among malignant subtypes, but there also exists a need to identify unifying characteristics to assist in rapid diagnosis and subsequent potential treatment. Herein, we investigated gene expression data of five different mature T-cell lymphoma subtypes (n = 187) and found 21 genes to be up- and down-regulated across all malignancies in comparison to healthy CD4+ and CD8+ T-cell controls (n = 52). From these results, we sought to characterize a role for caveolin-1 (CAV1), a gene with previous description in the progression of both solid and hematological tumors. Caveolin-1 was upregulated, albeit with a heterogeneous nature, across all mature T-cell lymphoma subtypes, a finding confirmed using immunohistochemical staining on an independent sampling of mature T-cell lymphoma biopsies (n = 65 cases). Further, stratifying malignant samples in accordance with high and low CAV1 expression revealed that higher expression of CAV1 in mature T-cell lymphomas is analogous with an enhanced inflammatory and invasive gene expression profile. Taken together, these results demonstrate a role for CAV1 in the tumor microenvironment of mature T-cell malignancies and point toward potential prognostic implications.
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Affiliation(s)
- Tyler A. Herek
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska, United States of America
| | - Timothy D. Shew
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska, United States of America
| | - Heather N. Spurgin
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska, United States of America
| | - Christine E. Cutucache
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska, United States of America
- * E-mail:
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19
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Liu C, Chapman NM, Karmaus PWF, Zeng H, Chi H. mTOR and metabolic regulation of conventional and regulatory T cells. J Leukoc Biol 2015; 97:837-847. [PMID: 25714803 DOI: 10.1189/jlb.2ri0814-408r] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Revised: 01/08/2015] [Accepted: 01/09/2015] [Indexed: 12/12/2022] Open
Abstract
mTOR signaling links bioenergetic and biosynthetic metabolism to immune responses. mTOR is activated by diverse upstream stimuli, including immune signals, growth factors, and nutrients. Recent studies highlight crucial roles of mTOR signaling in immune functions mediated by conventional T cells and Tregs In this review, we discuss the regulation of mTOR signaling in T cells and the functional impacts of mTOR and metabolic pathways on T cell-mediated immune responses, with a particular focus on the differentiation and function of Tregs.
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Affiliation(s)
- Chaohong Liu
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Nicole M Chapman
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Peer W F Karmaus
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Hu Zeng
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Hongbo Chi
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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20
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Chapman NM, Chi H. mTOR Links Environmental Signals to T Cell Fate Decisions. Front Immunol 2015; 5:686. [PMID: 25653651 PMCID: PMC4299512 DOI: 10.3389/fimmu.2014.00686] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 12/20/2014] [Indexed: 12/18/2022] Open
Abstract
T cell fate decisions play an integral role in maintaining the health of organisms under homeostatic and inflammatory conditions. The localized microenvironment in which developing and mature T cells reside provides signals that serve essential functions in shaping these fate decisions. These signals are derived from the immune compartment, including antigens, co-stimulation, and cytokines, and other factors, including growth factors and nutrients. The mechanistic target of rapamycin (mTOR), a vital sensor of signals within the immune microenvironment, is a central regulator of T cell biology. In this review, we discuss how various environmental cues tune mTOR activity in T cells, and summarize how mTOR integrates these signals to influence multiple aspects of T cell biology.
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Affiliation(s)
- Nicole M Chapman
- Department of Immunology, St. Jude Children's Research Hospital , Memphis, TN , USA
| | - Hongbo Chi
- Department of Immunology, St. Jude Children's Research Hospital , Memphis, TN , USA
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