1
|
Jiménez-García L, Mayer C, Burrola PG, Huang Y, Shokhirev MN, Lemke G. The TAM receptor tyrosine kinases Axl and Mer drive the maintenance of highly phagocytic macrophages. Front Immunol 2022; 13:960401. [PMID: 35967387 PMCID: PMC9373726 DOI: 10.3389/fimmu.2022.960401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 07/05/2022] [Indexed: 11/13/2022] Open
Abstract
Many apoptotic thymocytes are generated during the course of T cell selection in the thymus, yet the machinery through which these dead cells are recognized and phagocytically cleared is incompletely understood. We found that the TAM receptor tyrosine kinases Axl and Mer, which are co-expressed by a specialized set of phagocytic thymic macrophages, are essential components of this machinery. Mutant mice lacking Axl and Mer exhibited a marked accumulation of apoptotic cells during the time that autoreactive and nonreactive thymocytes normally die. Unexpectedly, these double mutants also displayed a profound deficit in the total number of highly phagocytic macrophages in the thymus, and concomitantly exhibited diminished expression of TIM-4, CD163, and other non-TAM phagocytic engulfment systems in the macrophages that remained. Importantly, these previously unrecognized deficits were not confined to the thymus, as they were also evident in the spleen and bone marrow. They had pleiotropic consequences for the double mutants, also previously unrecognized, which included dysregulation of hemoglobin turnover and iron metabolism leading to anemia.
Collapse
Affiliation(s)
- Lidia Jiménez-García
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Christopher Mayer
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Patrick G. Burrola
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Youtong Huang
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Maxim N. Shokhirev
- Razavi Newman Integrative Genomics and Bioinformatics Core, The Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Greg Lemke
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, United States
- Molecular Neurobiology Laboratory, Immunobiology and Microbial Pathogenesis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, United States
| |
Collapse
|
2
|
Lith SC, van Os BW, Seijkens TTP, de Vries CJM. 'Nur'turing tumor T cell tolerance and exhaustion: novel function for Nuclear Receptor Nur77 in immunity. Eur J Immunol 2020; 50:1643-1652. [PMID: 33063848 PMCID: PMC7702156 DOI: 10.1002/eji.202048869] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/28/2020] [Accepted: 10/14/2020] [Indexed: 12/14/2022]
Abstract
The nuclear receptor Nur77 is expressed in a multitude of tissues, regulating cell differentiation and homeostasis. Dysregulation of Nur77 signaling is associated with cancer, cardiovascular disease, and disorders of the CNS. The role of Nur77 in T cells has been studied for almost 30 years now. There is a clear appreciation that Nur77 is crucial for apoptosis of self‐reactive T cells. However, the regulation and function of Nur77 in mature T cells remains largely unclear. In an exciting development, Nur77 has been recently demonstrated to impinge on cancer immunotherapy involving chimeric antigen receptor (CAR) T cells and tumor infiltrating lymphocytes (TILs). These studies indicated that Nur77 deficiency reduced T cell tolerance and exhaustion, thus raising the effectiveness of immune therapy in mice. Based on these novel insights, it may be proposed that regulation of Nur77 activity holds promise for innovative drug development in the field of cellular immunotherapy in cancer. In this review, we therefore summarize the role of Nur77 in T cell selection and maturation; and further develop the idea of targeting its activity in these cells as a potential strategy to augment current cancer immunotherapy treatments.
Collapse
Affiliation(s)
- Sanne C Lith
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences, Institute for Infection and Immunity, Amsterdam, The Netherlands
| | - Bram W van Os
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences, Institute for Infection and Immunity, Amsterdam, The Netherlands
| | - Tom T P Seijkens
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences, Cancer Center Amsterdam, Amsterdam, The Netherlands.,Department of Internal Medicine, Department of Hematology, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands
| | - Carlie J M de Vries
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences, Institute for Infection and Immunity, Amsterdam, The Netherlands
| |
Collapse
|
3
|
Chen EW, Tay NQ, Brzostek J, Gascoigne NRJ, Rybakin V. A Dual Inhibitor of Cdc7/Cdk9 Potently Suppresses T Cell Activation. Front Immunol 2019; 10:1718. [PMID: 31402912 PMCID: PMC6670834 DOI: 10.3389/fimmu.2019.01718] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 07/09/2019] [Indexed: 01/05/2023] Open
Abstract
T cell activation is mediated by signaling pathways originating from the T cell receptor (TCR). Propagation of signals downstream of the TCR involves a cascade of numerous kinases, some of which have yet to be identified. Through a screening strategy that we have previously introduced, PHA-767491, an inhibitor of the kinases Cdc7 and Cdk9, was identified to impede TCR signaling. PHA-767491 suppressed several T cell activation phenomena, including the expression of activation markers, proliferation, and effector functions. We also observed a defect in TCR signaling pathways upon PHA-767491 treatment. Inhibition of Cdc7/Cdk9 impairs T cell responses, which could potentially be detrimental for the immune response to tumors, and also compromises the ability to resist infections. The Cdc7/Cdk9 inhibitor is a strong candidate as a cancer therapeutic, but its effect on the immune system poses a problem for clinical applications.
Collapse
Affiliation(s)
- Elijah W Chen
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Neil Q Tay
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Immunology Programme, Centre for Life Sciences, Life Sciences Institute, National University of Singapore, Singapore, Singapore.,Centre for Life Sciences (CeLS), NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore, Singapore
| | - Joanna Brzostek
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Nicholas R J Gascoigne
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Immunology Programme, Centre for Life Sciences, Life Sciences Institute, National University of Singapore, Singapore, Singapore.,Centre for Life Sciences (CeLS), NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore, Singapore
| | - Vasily Rybakin
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| |
Collapse
|
4
|
Zheng M, Li D, Zhao Z, Shytikov D, Xu Q, Jin X, Liang J, Lou J, Wu S, Wang L, Hu H, Zhou Y, Gao X, Lu L. Protein phosphatase 2A has an essential role in promoting thymocyte survival during selection. Proc Natl Acad Sci U S A 2019; 116:12422-7. [PMID: 31152132 DOI: 10.1073/pnas.1821116116] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The development of thymocytes to mature T cells in the thymus is tightly controlled by cellular selection, in which only a small fraction of thymocytes equipped with proper quality of TCRs progress to maturation. It is pivotal to protect the survival of the few T cells, which pass the selection. However, the signaling events, which safeguard the cell survival in thymus, are not totally understood. In this study, protein Ser/Thr phosphorylation in thymocytes undergoing positive selection is profiled by mass spectrometry. The results revealed large numbers of dephosphorylation changes upon T cell receptor (TCR) activation during positive selection. Subsequent substrate analysis pinpointed protein phosphatase 2A (PP2A) as the enzyme responsible for the dephosphorylation changes in developing thymocytes. PP2A catalytic subunit α (Ppp2ca) deletion in the T cell lineage in Ppp2ca flox/flox-Lck-Cre mice (PP2A cKO) displayed dysregulated dephosphorylation of apoptosis-related proteins in double-positive (DP) cells and caused substantially decreased numbers of DP CD4+ CD8+ cells. Increased levels of apoptosis in PP2A cKO DP cells were found to underlie aberrant thymocyte development. Finally, the defective thymocyte development in PP2A cKO mice could be rescued by either Bcl2 transgene expression or by p53 knockout. In summary, our work reveals an essential role of PP2A in promoting thymocyte development through the regulation of cell survival.
Collapse
|
5
|
Abstract
Macroautophagy (referred to as autophagy) is a fundamental intracellular process characterized by the sequestration of cytoplasmic compartments through double-membrane vesicles, termed autophagosomes. Recent studies have established important roles of autophagy in regulating T lymphocyte development and function. Resting T lymphocytes have basal levels of autophagy that is upregulated by T cell receptor stimulation. Several specific knockout or transgenic models have been developed during the past few years, and it has been revealed that autophagy plays an essential role in regulating thymocyte selection, peripheral T cell survival, and proliferation. The regulation of T cell development and function by autophagy is mediated through its role in regulating self-antigen presentation, intracellular organelle homeostasis, and energy production. Here we will review the current findings concerning how autophagy regulates T cell function, as well as compare different models in studying autophagy in T lymphocytes.
Collapse
Affiliation(s)
- Ming-Xiao He
- Department of Immunology, Duke University Durham, NC, USA
| | | | | | | |
Collapse
|
6
|
Haks MC, Pépin E, van den Brakel JHN, Smeele SAA, Belkowski SM, Kessels HWHG, Krimpenfort P, Kruisbeek AM. Contributions of the T cell receptor-associated CD3gamma-ITAM to thymocyte selection. J Exp Med 2002; 196:1-13. [PMID: 12093866 PMCID: PMC2194018 DOI: 10.1084/jem.20020268] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
The immunoreceptor tyrosine-based activation motifs (ITAMs) in the CD3 chains associated with the T cell receptor (TCR) are crucial for TCR signaling. To probe the role of the CD3gamma-ITAM in T cell development, we created knock-in mice in which the CD3gamma chain of the TCR complex is replaced by a mutant signaling-deficient CD3gamma chain, lacking the CD3gamma-ITAM. This mutation results in considerable impairment in positive selection in the polyclonal TCR repertoire. When CD3gamma-deltaITAM mice are crossed to mice expressing transgenic F5 TCRs, their thymocytes are completely unable to perform positive selection in vivo in response to intrathymic ligands. Also, the in vitro positive selection response of double-positive (DP) thymocytes with F5-CD3gamma-deltaITAM mutant receptors to their agonist ligand and many of its variants is severely impaired or abrogated. Yet, the binding and dissociation constants of agonist ligands for the F5 receptor are not affected by the CD3gamma-deltaITAM mutation. Furthermore, DP thymocytes with mutant receptors can respond to agonist ligand with normal antigen sensitivity and to normal levels, as shown by their ability to induce CD69 up-regulation, TCR down-regulation, negative selection, and ZAP70 and c-Jun NH2-terminal kinase activation. In sharp contrast, induction of extracellular signal-regulated kinase (ERK) activation and linker for activation of T cells (LAT) phosphorylation are severely impaired in these cells. Together, these findings underscore that intrinsic properties of the TCR-CD3 complex regulate selection at the DP checkpoint. More importantly, this analysis provides the first direct genetic evidence for a role of the CD3gamma-ITAM in TCR-driven thymocyte selection.
Collapse
MESH Headings
- Adaptor Proteins, Signal Transducing
- Amino Acid Motifs/physiology
- Animals
- Antigens, CD/metabolism
- Antigens, Differentiation, T-Lymphocyte/metabolism
- CD3 Complex/genetics
- CD3 Complex/immunology
- CD3 Complex/metabolism
- CD4 Antigens/biosynthesis
- CD8 Antigens/biosynthesis
- Carrier Proteins/metabolism
- Cell Differentiation/immunology
- Cells, Cultured
- Crosses, Genetic
- Enzyme Activation/drug effects
- Flow Cytometry
- In Vitro Techniques
- JNK Mitogen-Activated Protein Kinases
- Lectins, C-Type
- Ligands
- Membrane Proteins
- Mice
- Mice, Mutant Strains
- Mitogen-Activated Protein Kinases/metabolism
- Mutation
- Phosphoproteins/metabolism
- Phosphorylation
- Protein-Tyrosine Kinases/metabolism
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Signal Transduction/immunology
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Thymus Gland/cytology
- Thymus Gland/immunology
- Thymus Gland/metabolism
- ZAP-70 Protein-Tyrosine Kinase
Collapse
Affiliation(s)
- Mariëlle C Haks
- Division of Immunology, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Abstract
The mouse thymus changes dramatically during pregnancy. It shrinks in size, and the cortex is extensively reduced from midpregnancy onwards. Despite this, there is surprisingly little evidence for any increase in apoptosis, and considerable evidence that mitosis of thymocytes continues throughout pregnancy. In spite of overall involution the thymic medulla actually expands in midpregnancy due to a combination of mitosis of epithelial cells and an accumulation of lymphocytes. The extent and nature of these changes are examined in this study at the ultrastructural level. The epithelial cells of the subcapsular cortex (type 1 cells) become wrinkled and exhibit powers of phagocytosis, whilst the other cortical epithelial cells are relatively unchanged, although the formation of epithelial/thymocyte rosettes and thymic nurse cells is more clearly seen in midpregnancy than usual. Other changes associated with pregnancy involve the medullary epithelial cells that undergo an increased level of mitosis. Their greater numbers surround accumulations of lymphocytes to form the characteristic medullary epithelial rings. Cell movement through blood vessel walls was clearly observed in midpregnancy, but not at other times. Interdigitating cells in the medulla become more conspicuous as pregnancy proceeds and the cells become phagocytic. The endoplasmic reticulum in plasma cells becomes expanded, indicating increased secretory activity. These results highlight the active nature of the thymus in pregnancy in spite of its involution. This picture contradicts the conventional notion that an involuted thymus is inactive.
Collapse
Affiliation(s)
- M D Kendall
- Thymus Laboratory, Molecular Immunology Programme, The Babraham Institute, Cambridge, UK.
| | | |
Collapse
|
8
|
Jones RG, Parsons M, Bonnard M, Chan VS, Yeh WC, Woodgett JR, Ohashi PS. Protein kinase B regulates T lymphocyte survival, nuclear factor kappaB activation, and Bcl-X(L) levels in vivo. J Exp Med 2000; 191:1721-34. [PMID: 10811865 PMCID: PMC2193154 DOI: 10.1084/jem.191.10.1721] [Citation(s) in RCA: 262] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The serine/threonine kinase protein kinase B (PKB)/Akt mediates cell survival in a variety of systems. We have generated transgenic mice expressing a constitutively active form of PKB (gag-PKB) to examine the effects of PKB activity on T lymphocyte survival. Thymocytes and mature T cells overexpressing gag-PKB displayed increased active PKB, enhanced viability in culture, and resistance to a variety of apoptotic stimuli. PKB activity prolonged the survival of CD4(+)CD8(+) double positive (DP) thymocytes in fetal thymic organ culture, but was unable to prevent antigen-induced clonal deletion of thymocytes expressing the major histocompatibility complex class I-restricted P14 T cell receptor (TCR). In mature T lymphocytes, PKB can be activated in response to TCR stimulation, and peptide-antigen-specific proliferation is enhanced in T cells expressing the gag-PKB transgene. Both thymocytes and T cells overexpressing gag-PKB displayed elevated levels of the antiapoptotic molecule Bcl-X(L). In addition, the activation of peripheral T cells led to enhanced nuclear factor (NF)-kappaB activation via accelerated degradation of the NF-kappaB inhibitory protein IkappaBalpha. Our data highlight a physiological role for PKB in promoting survival of DP thymocytes and mature T cells, and provide evidence for the direct association of three major survival molecules (PKB, Bcl-X(L), and NF-kappaB) in vivo in T lymphocytes.
Collapse
Affiliation(s)
- Russell G. Jones
- Department of Medical Biophysics, Ontario Cancer Institute, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| | - Michael Parsons
- Department of Medical Biophysics, Ontario Cancer Institute, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| | | | - Vera S.F. Chan
- Department of Medical Biophysics, Ontario Cancer Institute, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| | - Wen-Chen Yeh
- Department of Medical Biophysics, Ontario Cancer Institute, University of Toronto, Toronto, Ontario M5G 2M9, Canada
- Amgen Institute, Toronto, Ontario M5G 2C1, Canada
| | - James R. Woodgett
- Department of Medical Biophysics, Ontario Cancer Institute, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| | - Pamela S. Ohashi
- Department of Medical Biophysics, Ontario Cancer Institute, University of Toronto, Toronto, Ontario M5G 2M9, Canada
- Department of Immunology, Ontario Cancer Institute, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| |
Collapse
|