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Saidakova EV. Lymphopenia and Mechanisms of T-Cell Regeneration. CELL AND TISSUE BIOLOGY 2022; 16:302-311. [PMID: 35967247 PMCID: PMC9358362 DOI: 10.1134/s1990519x2204006x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/11/2022] [Accepted: 01/11/2022] [Indexed: 11/24/2022]
Abstract
Chronic lymphopenia, in particular, T-lymphocyte deficiency, increases the risk of death from cancer, cardiovascular and respiratory diseases and serves as a risk factor for a severe course and poor outcome of infectious diseases such as COVID-19. The regeneration of T-lymphocytes is a complex multilevel process, many questions of which still remain unanswered. The present review considers two main pathways of increasing the T-cell number in lymphopenia: production in the thymus and homeostatic proliferation in the periphery. Literature data on the signals that regulate each pathway are summarized. Their contribution to the quantitative and qualitative restoration of the immune cell pool is analyzed. The features of CD4+ and CD8+ T-lymphocytes’ regeneration are considered.
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Affiliation(s)
- E. V. Saidakova
- Institute of Ecology and Genetics of Microorganisms, Ural Branch, Russian Academy of Sciences—Branch of Perm Federal Research Center, Ural Branch, Russian Academy of Sciences, 614081 Perm, Russia
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2
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Cui G, Shimba A, Ma G, Takahara K, Tani-Ichi S, Zhu Y, Asahi T, Abe A, Miyachi H, Kitano S, Hara T, Yasunaga JI, Suwanai H, Yamada H, Matsuoka M, Ueki K, Yoshikai Y, Ikuta K. IL-7R-Dependent Phosphatidylinositol 3-Kinase Competes with the STAT5 Signal to Modulate T Cell Development and Homeostasis. THE JOURNAL OF IMMUNOLOGY 2020; 204:844-857. [PMID: 31924648 DOI: 10.4049/jimmunol.1900456] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 12/10/2019] [Indexed: 11/19/2022]
Abstract
T cell development and homeostasis requires IL-7R α-chain (IL-7Rα) signaling. Tyrosine Y449 of the IL-7Rα is essential to activate STAT5 and PI3K, whereas PI3K recruitment requires IL-7Rα methionine M452. How IL-7Rα activates and regulates both signaling pathways differentially remains unclear. To characterize differential signaling, we established two lines of IL-7Rα mutant mice: IL-7R-Y449F mice and IL-7R-M452L mice. IL-7R-Y449F mice showed decreased PI3K and STAT5 signals, whereas IL-7R-M452L mice showed decreased PI3K but significantly increased STAT5 signaling, owing to a competition between PI3K and STAT5 signaling through Y449 of IL-7Rα. The number of T, B, and mature innate lymphoid cells were markedly reduced in IL-7R-Y449F mice, whereas IL-7R-M452L mice showed impaired early T cell development and memory precursor effector T cell maintenance with the downregulation of transcription factor T cell factor-1. Peripheral T cell numbers increased in IL-7R-M452L mice with enhanced survival and homeostatic proliferation. Furthermore, although wild type and IL-7R-Y449F mice showed comparable Th1/Th2 differentiation, IL-7R-M452L mice exhibited impaired Th17 differentiation. We conclude that PI3K competes with STAT5 under IL-7Rα and maintains an appropriate signal balance for modulating T cell development and homeostasis. To our knowledge, this study provides a new insight into complex regulation of IL-7Rα signaling, which supports immune development and responses.
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Affiliation(s)
- Guangwei Cui
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Akihiro Shimba
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Guangyong Ma
- Laboratory of Virus Control, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Kazuhiko Takahara
- Laboratory of Immunobiology, Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Shizue Tani-Ichi
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.,Laboratory of Biological Chemistry, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Yuanbo Zhu
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.,Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Takuma Asahi
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.,Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Akifumi Abe
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Hitoshi Miyachi
- Reproductive Engineering Team, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Satsuki Kitano
- Reproductive Engineering Team, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Takahiro Hara
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Jun-Ichirou Yasunaga
- Laboratory of Virus Control, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Hirotsugu Suwanai
- Department of Diabetes, Endocrinology and Metabolism, Tokyo Medical University Hospital, Tokyo 160-0023, Japan
| | - Hisakata Yamada
- Division of Host Defense, Network Center for Infectious Diseases, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Masao Matsuoka
- Laboratory of Virus Control, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.,Department of Hematology, Rheumatology and Infectious Disease, Faculty of Life Sciences, Kumamoto University, Kumamoto 860-8556, Japan; and
| | - Kohjiro Ueki
- Department of Molecular Diabetic Medicine, Diabetes Research Center, Research Institute, National Center for Global Health and Medicine, Tokyo 162-8655, Japan
| | - Yasunobu Yoshikai
- Division of Host Defense, Network Center for Infectious Diseases, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Koichi Ikuta
- Laboratory of Immune Regulation, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan;
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3
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Cabello-Kindelan C, de la Barrera A, Malek TR, Bayer AL. In vivo environment necessary to support transplanted donor mouse T regulatory cells. Am J Transplant 2014; 14:1032-45. [PMID: 24618297 DOI: 10.1111/ajt.12650] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 12/06/2013] [Accepted: 12/26/2013] [Indexed: 01/25/2023]
Abstract
CD4(+) Foxp3(+) T regulatory cells (Tregs ) are essential for maintaining immunological tolerance, which could be harnessed for novel cell-based therapies to prevent allograft rejection and control autoimmunity. However, the use of Tregs for therapy is hindered by the inability to generate sufficient cell numbers to inhibit desired immune response(s) and achieve stable engraftment of the donor-Treg cell inoculums. The present study was undertaken to investigate the in vivo requirements to promote engraftment of adoptively transferred Tregs and induce tolerance. We established that not only is peripheral space required, but competition from endogenous Tregs must be minimized for successful donor-Treg engraftment with IL-2 critical for driving their proliferation and survival. Moreover, these studies revealed a critical level of donor-Treg engraftment was required for tolerance induction to skin transplants. These mouse studies lay the foundation for development of novel Treg approaches for tolerance induction in the clinic involving not only organ or cellular transplantation, but also to re-establish self-tolerance in autoimmune settings.
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Affiliation(s)
- C Cabello-Kindelan
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL
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4
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Ashbaugh JJ, Brambilla R, Karmally SA, Cabello C, Malek TR, Bethea JR. IL7Rα contributes to experimental autoimmune encephalomyelitis through altered T cell responses and nonhematopoietic cell lineages. THE JOURNAL OF IMMUNOLOGY 2013; 190:4525-34. [PMID: 23530149 DOI: 10.4049/jimmunol.1203214] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A mutation in the IL7Rα locus has been identified as a risk factor for multiple sclerosis (MS), a neurodegenerative autoimmune disease characterized by inflammation, demyelination, and axonal damage. IL7Rα has well documented roles in lymphocyte development and homeostasis, but its involvement in disease is largely understudied. In this study, we use the experimental autoimmune encephalomyelitis (EAE) model of MS to show that a less severe form of the disease results when IL7Rα expression is largely restricted to thymic tissue in IL7RTg(IL7R-/-) mice. Compared with wild-type (WT) mice, IL7RTg(IL7R-/-) mice exhibited reduced paralysis and myelin damage that correlated with dampened effector responses, namely decreased TNF production. Furthermore, treatment of diseased WT mice with neutralizing anti-IL7Rα Ab also resulted in significant improvement of EAE. In addition, chimeric mice were generated by bone marrow transplant to limit expression of IL7Rα to cells of either hematopoietic or nonhematopoietic origin. Mice lacking IL7Rα only on hematopoietic cells develop severe EAE, suggesting that IL7Rα expression in the nonhematopoietic compartment contributes to disease. Moreover, novel IL7Rα expression was identified on astrocytes and oligodendrocytes endogenous to the CNS. Chimeric mice that lack IL7Rα only on nonhematopoietic cells also develop severe EAE, which further supports the role of IL7Rα in T cell effector function. Conversely, mice that lack IL7Rα throughout both compartments are dramatically protected from disease. Taken together, these data indicate that multiple cell types use IL7Rα signaling in the development of EAE, and inhibition of this pathway should be considered as a new therapeutic avenue for MS.
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Affiliation(s)
- Jessica J Ashbaugh
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
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5
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Bayer AL, Lee JY, de la Barrera A, Surh CD, Malek TR. A function for IL-7R for CD4+CD25+Foxp3+ T regulatory cells. THE JOURNAL OF IMMUNOLOGY 2008; 181:225-34. [PMID: 18566388 DOI: 10.4049/jimmunol.181.1.225] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The IL-2/IL-2R interaction is important for development and peripheral homeostasis of T regulatory (Treg) cells. IL-2- and IL-2R-deficient mice are not completely devoid of Foxp3+ cells, but rather lack population of mature CD4+CD25+Foxp3high Treg cells and contain few immature CD4+CD25-Foxp3low T cells. Interestingly, common gamma chain (gammac) knockout mice have been shown to have a near complete absence of Foxp3+ Treg cells, including the immature CD25-Foxp3low subset. Therefore, other gammac-cytokine(s) must be critically important during thymic development of CD4+CD25+Foxp3+ Treg cells apart from the IL-2. The present study was undertaken to determine whether the gammac-cytokines IL-7 or IL-15 normally contribute to expression of Foxp3 and Treg cell production. These studies revealed that mice double deficient in IL-2Rbeta and IL-7Ralpha contained a striking lack in the CD4+Foxp3+ population and the Treg cell defect recapitulated the gammac knockout mice. In the absence of IL-7R signaling, IL-15/IL-15R interaction is dispensable for the production of CD4+CD25+Foxp3+ Treg cells, indicating that normal thymic Treg cell production likely depends on signaling through both IL-2 and IL-7 receptors. Selective thymic reconstitution of IL-2Rbeta in mice double deficient in IL-2Rbeta and IL-7Ralpha established that IL-2Rbeta is dominant and sufficient to restore production of Treg cells. Furthermore, the survival of peripheral CD4+Foxp3low cells in IL-2Rbeta-/- mice appears to depend upon IL-7R signaling. Collectively, these data indicate that IL-7R signaling contributes to Treg cell development and peripheral homeostasis.
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Affiliation(s)
- Allison L Bayer
- Department of Microbiology and Immunology, Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.
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6
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Maki K, Ikuta K. MEK1/2 induces STAT5-mediated germline transcription of the TCRgamma locus in response to IL-7R signaling. THE JOURNAL OF IMMUNOLOGY 2008; 181:494-502. [PMID: 18566415 DOI: 10.4049/jimmunol.181.1.494] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The IL-7R plays an essential role in gammadelta T cell development by inducing V-J recombination of the TCRgamma locus through STAT5. Although tyrosine residues in the intracellular domain of the mouse IL-7R alpha-chain (IL-7Ralpha) have been implicated in STAT5 activation, it is still unknown whether they are essential for gammadelta T cell development. In this study, we showed that those IL-7Ralpha tyrosine residues are not essential for gammadelta T cell development, because phenylalanine replacement of four intracellular tyrosine residues (IL-7R-FFFF) partially rescued gammadelta T cell development of IL-7Ralpha-/- progenitors. To examine signaling pathways activated by IL-7R-FFFF, we introduced a chimeric receptor consisting of the human IL-4R alpha-chain and mouse IL-7R-FFFF (4R/7R-FFFF) into an IL-7-dependent pre-B cell line and found that 4R/7R-FFFF induced TCRgamma germline transcription and STAT5 activation. Treatment of cells with MEK1/2 inhibitors significantly decreased levels of TCRgamma germline transcription and STAT5 tyrosine phosphorylation mediated by 4R/7R-FFFF, suggesting that MEK1/2 plays an alternative role in STAT5 activation by IL-7R. MEK1/2 associated with STAT5 and induced STAT5 tyrosine phosphorylation and DNA binding activity. Furthermore, MEK1 directly phosphorylated a STAT5 tyrosine residue in vitro. Finally, active MEK1 partially rescued TCRgamma germline transcription by IL-7R in a pre-T cell line. These results demonstrate that MEK1/2 induces TCRgamma germline transcription by phosphorylating STAT5 through IL-7R-FFFF and suggest a potential role for MAPK in IL-7R tyrosine-independent activation of STAT5.
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Affiliation(s)
- Kazushige Maki
- Laboratory of Biological Protection, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto, Japan
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7
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Impaired thymopoiesis in interleukin-7 receptor transgenic mice is not corrected by Bcl-2. Cell Immunol 2008; 250:31-9. [PMID: 18321477 DOI: 10.1016/j.cellimm.2008.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 01/11/2008] [Accepted: 01/11/2008] [Indexed: 12/14/2022]
Abstract
Murine thymocytes down-regulate IL-7 responsiveness following beta-selection and reacquire sensitivity after positive selection. To assess the potential consequences of IL-7 signaling during this phase of development, transgenic IL-7 receptor alpha (IL-7Ralpha) mice were evaluated for IL-7 responsiveness as gauged by STAT-5 phosphorylation. Transgenic IL-7Ralpha expression increased the percentage of thymocytes responsive to IL-7 yet resulted in a decrease in total thymic cellularity. Aberrant thymocyte development in transgenic mice was first manifested by a reduction of DN3 thymocytes that correlated with lower Bcl-2 expression. Surprisingly, transgenic restoration of Bcl-2 expression did not correct thymic hypocellularity induced by IL-7Ralpha overexpression. These findings demonstrate that failure to appropriately downregulate IL-7Ralpha expression interferes with thymocyte development past the pro-T stage resulting in significantly lower levels of mature thymocytes.
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8
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Carrio R, Rolle CE, Malek TR. Non-redundant role for IL-7R signaling for the survival of CD8+ memory T cells. Eur J Immunol 2007; 37:3078-88. [PMID: 17935075 DOI: 10.1002/eji.200737585] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
IL-7 and IL-15 are important cytokines for CD8 memory T cells. However, the extent that IL-7 is essential for CD8 T cell memory remains unclear because blocking IL-7 in vivo results in near complete inhibition of T cell development with the few mature T cells exhibiting functional abnormalities. To bypass this complication, CD8 memory development was examined utilizing a mouse model where transgenic IL-7Ralpha was selectively expressed in the thymus of IL-7Ralpha(-/-) mice. T cell development was corrected but the resulting peripheral T cells were essentially IL-7 non-responsive. Activation of IL-7R-defective OT-I CD8(+) T cells with OVA(257-264) and IL-2 readily yielded CTL. Upon further culture with IL-15, these CTL expressed phenotypic and functional properties of central memory-like cells. Thus, IL-7R-defective CD8(+) T cells do not exhibit intrinsic defects in effector or memory development. When IL-7R-defective OT-I CTL were adoptively transferred into normal or IL-15(-/-) recipient mice in a non-inflammatory setting, they converted into memory-like cells, but did not persist, which was even more striking in IL-15(-/-) recipients. This poor persistence was rescued after expression of transgenic Bcl-2 in IL-7R-defective OT-I T cells. Collectively, these data indicate that IL-7 is non-redundantly required for the survival of CD8 memory T cells.
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Affiliation(s)
- Roberto Carrio
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33101, USA
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9
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Kittipatarin C, Khaled AR. Interlinking interleukin-7. Cytokine 2007; 39:75-83. [PMID: 17768066 PMCID: PMC2040031 DOI: 10.1016/j.cyto.2007.07.183] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 07/16/2007] [Accepted: 07/17/2007] [Indexed: 01/31/2023]
Abstract
The signaling processes that maintain the homeostatic proliferation of peripheral T-cells and result in their self-renewal largely remain to be elucidated. Much focus has been placed on the anti-apoptotic function of the cytokine, interleukin-7 (IL-7), during T-cell development. But a more critical role has been ascribed to IL-7 as a mediator of peripheral T-cell maintenance. The biological effects responsive to IL-7 signaling are transduced through only a few well-known pathways. In this review we will focus on the signals transduced by IL-7 and similar cytokines, examining how proliferative signals originate from cytokine receptors, are amplified and eventually alter gene expression. In this regard we will highlight the crosstalk between pathways that promote survival, drive cell cycle progression and most importantly provide the needed energy to sustain these critical cellular activities. Though this review showcases much of what has been learned about IL-7 proliferative signaling, it also reveals the significant gaps in our knowledge about cytokine signaling in the very relevant context of peripheral T-cell homeostasis.
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Affiliation(s)
- Christina Kittipatarin
- Biomolecular Science Center, University of Central Florida, 12722 Research Parkway, Orlando, FL 32826, USA
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10
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Jahn T, Sindhu S, Gooch S, Seipel P, Lavori P, Leifheit E, Weinberg K. Direct interaction between Kit and the interleukin-7 receptor. Blood 2007; 110:1840-7. [PMID: 17554063 PMCID: PMC1976346 DOI: 10.1182/blood-2005-12-028019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In vivo analyses of thymopoiesis in mice defective in signaling through Kit and gammac or Kit and IL-7Ralpha demonstrate synergy and partial complementation of gammac or IL-7-mediated signaling by the Kit signaling pathway. Our molecular analysis in T-lymphoid cells as well as in nonhematopoietic cells shows that Kit and IL-7R signaling pathways directly interact. KL-mediated activation of Kit induced strong tyrosine phosphorylation of gammac and IL-7Ralpha in the absence of IL-7. Activated Kit formed a complex with either IL-7Ralpha or gammac, and tyrosine phosphorylation of both subunits occurred independently of Jak3, suggesting that gammac and IL-7Ralpha are each direct substrates of Kit. Kit activated Jak3 in an IL-7R-dependent manner. Moreover, deficient Stat5 activation of the Kit mutant YY567/569FF lacking intrinsic Src activation capacity was partially reconstituted in the presence of IL-7R and Jak3. Based on the molecular data, we propose a model of Kit-mediated functional activation of gammac-containing receptors such as IL-7R, similar to the interaction between Kit and Epo-R. Such indirect activation of the Jak-Stat pathway induced by the interaction between an RTK and type I cytokine receptor could be the underlying mechanism for a context-specific signaling repertoire of a pleiotropic RTK-like Kit.
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Affiliation(s)
- Thomas Jahn
- Division of Research Immunology and Bone Marrow Transplantation, Childrens Hospital Los Angeles, CA, USA.
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11
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Abstract
Interleukin-7 (IL-7) is produced by stromal cells in lymphoid tissues and is required for the development of T cells and for their persistence in the periphery. Unlike many other cytokines that act on lymphocytes, IL-7 production by stromal cells is not substantially affected by extrinsic stimuli. So, the amount of available IL-7 protein is thought to be regulated by the rate that it is scavenged by T cells. As we review here, there is mounting evidence indicating that the amount of IL-7 receptor expressed on a cell not only determines how vigorously the cell responds to IL-7, but it can also determine how efficiently the cell consumes IL-7 and, therefore, affect the supply of this limiting resource in the niche.
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Affiliation(s)
- Renata Mazzucchelli
- Laboratory of Molecular Immunoregulation, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 560, Room 31-71, Frederick, Maryland 21702-1201, USA
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12
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Yu A, Malek TR. Selective availability of IL-2 is a major determinant controlling the production of CD4+CD25+Foxp3+ T regulatory cells. THE JOURNAL OF IMMUNOLOGY 2007; 177:5115-21. [PMID: 17015695 DOI: 10.4049/jimmunol.177.8.5115] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The development and maintenance of T regulatory (Treg) cells critically depend on IL-2. This requirement for IL-2 might be due to specificity associated with IL-2R signal transduction or because IL-2 was uniquely present in the niche in which Treg cells reside. To address this issue, we examined the capacity of IL-7R-dependent signaling to support Treg cell production and prevent autoimmunity in IL-2Rbeta(-/-) mice. Expression of transgenic wild-type IL-7R or a chimeric receptor that consisted of the extracytoplasmic domain of the IL-7R alpha-chain and the cytoplasmic domain of IL-2R beta-chain in IL-2Rbeta(-/-) mice did not prevent autoimmunity. Importantly, expression of a chimeric receptor that consisted of the extracytoplasmic domain of the IL-2R beta-chain and the cytoplasmic domain of IL-7R alpha-chain in IL-2Rbeta(-/-) mice led to Treg cells production in the thymus and periphery and prevented autoimmunity. Signaling through the IL-2R or chimeric IL-2Rbeta/IL-7Ralpha in vivo or the culture of thymocytes from IL-2Rbeta(-/-) mice with IL-7 led to up-regulation of Foxp3 and CD25 on Treg cells. These findings indicate that IL-7R signal transduction is competent to promote Treg cell production, but this signaling requires triggering through IL-2 by binding to the extracytoplasmic portion of the IL-2R via this chimeric receptor. Thus, a major factor controlling the nonredundant activity of the IL-2R is selective compartmentalization of IL-2-producing cells with Treg cells in vivo.
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Affiliation(s)
- Aixin Yu
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33101, USA
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13
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Grunebaum E, Sharfe N, Roifman CM. Human T cell immunodeficiency: when signal transduction goes wrong. Immunol Res 2006; 35:117-26. [PMID: 17003514 DOI: 10.1385/ir:35:1:117] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 11/11/2022]
Abstract
Severe combined immunodeficiency (SCID) is a heterogeneous group of diseases that are invariably fatal in infancy unless treated by hematopoietic stem cell replacement. For many years we have worked to better manage patients affected by SCID through rapid and accurate diagnosis followed by treatment aimed at achieving long-lasting immune reconstitution. By extensive immunological, biochemical, and genetic studies of patient samples, and with the realization of differences between human and murine T cell development, we have successfully been able to identify some of the molecular defects causing SCID. Among these discoveries, we described the first mutated signal transduction protein in T cells (ZAP-70); the first genetic defect leading to SCID and autoimmune phenomena (IL2R alpha); and, recently, the critical importance of CD3delta in the development of T cells. Our efforts have significantly advanced the understanding of the role of some of the signal-transducing proteins in T cell maturation and function. This review summarizes several of these discoveries and some of their impact on our understanding of T cells development, function, and homeostasis in humans.
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Affiliation(s)
- Eyal Grunebaum
- Division of Immunology/Allergy and the Infection, Immunity, Injury and Repair Program, The Research Institute and The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
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14
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David-Fung ES, Yui MA, Morales M, Wang H, Taghon T, Diamond RA, Rothenberg EV. Progression of regulatory gene expression states in fetal and adult pro-T-cell development. Immunol Rev 2006; 209:212-36. [PMID: 16448545 PMCID: PMC4157939 DOI: 10.1111/j.0105-2896.2006.00355.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Precursors entering the T-cell developmental pathway traverse a progression of states characterized by distinctive patterns of gene expression. Of particular interest are regulatory genes, which ultimately control the dwell time of cells in each state and establish the mechanisms that propel them forward to subsequent states. Under particular genetic and developmental circumstances, the transitions between these states occur with different timing, and environmental feedbacks may shift the steady-state accumulations of cells in each state. The fetal transit through pro-T-cell stages is faster than in the adult and subject to somewhat different genetic requirements. To explore causes of such variation, this review presents previously unpublished data on differentiation gene activation in pro-T cells of pre-T-cell receptor-deficient mutant mice and a quantitative comparison of the profiles of transcription factor gene expression in pro-T-cell subsets of fetal and adult wildtype mice. Against a background of consistent gene expression, several regulatory genes show marked differences between fetal and adult expression profiles, including those encoding two basic helix-loop-helix antagonist Id factors, the Ets family factor SpiB and the Notch target gene Deltex1. The results also reveal global differences in regulatory alterations triggered by the first T-cell receptor-dependent selection events in fetal and adult thymopoiesis.
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15
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Nunnari G, Xu Y, Acheampong EA, Fang J, Daniel R, Zhang C, Zhang H, Mukhtar M, Pomerantz RJ. Exogenous IL-7 induces Fas-mediated human neuronal apoptosis: potential effects during human immunodeficiency virus type 1 infection. J Neurovirol 2005; 11:319-28. [PMID: 16162475 DOI: 10.1080/13550280500187005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The use of exogenous cytokines is part of translational immune-antiretroviral approaches to induce immune reconstitution and possibly eliminate the persistence of human immunodeficiency virus type 1 (HIV-1) in virally suppressed infected individuals on highly active antiretroviral therapy (HAART). Recently, our laboratories demonstrated that interleukin-7 (IL-7) has significant efficiency in stimulating HIV-1 replication from proviral latency in CD4+ T lymphocytes of infected patients. The authors now investigated the possible role of IL-7 in HIV-1-associated dementia (HAD). The authors demonstrated that the IL-7 receptor is expressed on both human neurons (i.e., differentiated NT2 cells) and human astrocytes, with relatively higher mRNA levels in neurons. The translational protein levels of IL-7 receptor alpha were not proportional to those of the mRNA levels in these central nervous system (CNS)-based cell types. Exogenous IL-7 was observed to only slightly down-regulate IL-7 receptor alpha expression on both neurons and astrocytes, as assayed by Western blotting. Instead of promoting survival, surprisingly, exogenous IL-7 induced neuronal apoptosis, as detected by TUNEL assays. Furthermore, IL-7 augmented neuronal apoptosis induced by HIV-1 gp120. Human apoptosis genomic microarray analyses of IL-7-treated human neurons showed up-regulated expression of proapoptotic genes: protein kinases, caspase-10, FAST kinase, tumor necrosis factor (TNF) receptor, and BCL2-antagonist of cell death. These data suggest that IL-7 leads to neuronal apoptosis by a molecular mechanism(s) that occurs via Fas-mediated activation-induced cell death. These studies may therefore not only be key in evaluating the potential use of IL-7 in vivo as a therapeutic modality, but also suggest that IL-7, which is increased endogenously in HIV-1-infected individuals late in disease, may be involved in the neuronal apoptosis demonstrated during HAD.
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Affiliation(s)
- Giuseppe Nunnari
- Center for Human Virology and Biodefense, Division of Infectious Diseases and Environmental Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
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16
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Jiang Q, Li WQ, Aiello FB, Mazzucchelli R, Asefa B, Khaled AR, Durum SK. Cell biology of IL-7, a key lymphotrophin. Cytokine Growth Factor Rev 2005; 16:513-33. [PMID: 15996891 DOI: 10.1016/j.cytogfr.2005.05.004] [Citation(s) in RCA: 250] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
IL-7 is essential for the development and survival of T lymphocytes. This review is primarily from the perspective of the cell biology of the responding T cell. Beginning with IL-7 receptor structure and regulation, the major signaling pathways appear to be via PI3K and Stat5, although the requirement for either has yet to be verified by published knockout experiments. The proliferation pathway induced by IL-7 differs from conventional growth factors and is primarily through posttranslational regulation of p27, a Cdk inhibitor, and Cdc25a, a Cdk-activating phosphatase. The survival function of IL-7 is largely through maintaining a favorable balance of bcl-2 family members including Bcl-2 itself and Mcl-1 on the positive side, and Bax, Bad and Bim on the negative side. There are also some remarkable metabolic effects of IL-7 withdrawal. Studies of IL-7 receptor signaling have yet to turn up unique pathways, despite the unique requirement for IL-7 in T cell biology. There remain significant questions regarding IL-7 production and the major producing cells have yet to be fully characterized.
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Affiliation(s)
- Qiong Jiang
- Laboratory of Molecular Immunoregulation, Center for Cancer Research, National Cancer Institute, NIH, Frederick, MD, USA
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17
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Giliani S, Mori L, de Saint Basile G, Le Deist F, Rodriguez-Perez C, Forino C, Mazzolari E, Dupuis S, Elhasid R, Kessel A, Galambrun C, Gil J, Fischer A, Etzioni A, Notarangelo LD. Interleukin-7 receptor alpha (IL-7Ralpha) deficiency: cellular and molecular bases. Analysis of clinical, immunological, and molecular features in 16 novel patients. Immunol Rev 2005; 203:110-26. [PMID: 15661025 DOI: 10.1111/j.0105-2896.2005.00234.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Analysis of gene-targeted mice and patients with severe combined immunodeficiency due to mutations of the alpha chain of the interleukin-7 receptor (IL-7Ralpha) has shown important differences between mice and humans in the role played by IL-7 in lymphoid development. More recently, it has been shown that IL-7Ralpha is also shared by the receptor for another cytokine, thymic stromal lymphopoietin (TSLP). In this review, we discuss recent advances in IL-7- and TSLP-mediated signaling. We also report on the clinical and immunological features of 16 novel patients with IL-7Ralpha deficiency and discuss the results of hematopoietic stem cell transplantation.
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Affiliation(s)
- Silvia Giliani
- Angelo Nocivelli Institute of Molecular Medicine, Department of Pediatrics, University of Brescia, Italy.
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18
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Zamisch M, Moore-Scott B, Su DM, Lucas PJ, Manley N, Richie ER. Ontogeny and regulation of IL-7-expressing thymic epithelial cells. THE JOURNAL OF IMMUNOLOGY 2005; 174:60-7. [PMID: 15611228 DOI: 10.4049/jimmunol.174.1.60] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Epithelial cells in the thymus produce IL-7, an essential cytokine that promotes the survival, differentiation, and proliferation of thymocytes. We identified IL-7-expressing thymic epithelial cells (TECs) throughout ontogeny and in the adult mouse thymus by in situ hybridization analysis. IL-7 expression is initiated in the thymic fated domain of the early primordium by embryonic day 11.5 and is expressed in a Foxn1-independent pathway. Marked changes occur in the localization and regulation of IL-7-expressing TECs during development. IL-7-expressing TECs are present throughout the early thymic rudiment. In contrast, a major population of IL-7-expressing TECs is localized to the medulla in the adult thymus. Using mouse strains in which thymocyte development is arrested at various stages, we show that fetal and postnatal thymi differ in the frequency and localization of IL-7-expressing TECs. Whereas IL-7 expression is initiated independently of hemopoietic-derived signals during thymic organogenesis, thymocyte-derived signals play an essential role in regulating IL-7 expression in the adult TEC compartment. Moreover, different thymocyte subsets regulate the expression of IL-7 and keratin 5 in adult cortical epithelium, suggesting that despite phenotypic similarities, the cortical TEC compartments of wild-type and RAG-1(-/-) mice are developmentally and functionally distinct.
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Affiliation(s)
- Monica Zamisch
- Science Park-Research Division, University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA
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19
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Munitic I, Williams JA, Yang Y, Dong B, Lucas PJ, El Kassar N, Gress RE, Ashwell JD. Dynamic regulation of IL-7 receptor expression is required for normal thymopoiesis. Blood 2004; 104:4165-72. [PMID: 15328149 DOI: 10.1182/blood-2004-06-2484] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Interleukin-7 receptor (IL-7R) levels are tightly controlled during ontogeny: high on double-negative (DN) cells, absent on double-positive (DP) cells, and high once again on thymocytes undergoing positive selection. To determine if loss of IL-7–mediated survival signals in DP cells is necessary for normal antigen-specific selection, we created T-lineage–specific IL-7R α chain (IL-7Rα) transgenic (Tg) mice in which IL-7R is expressed throughout ontogeny. There was no effect of the IL-7Rα Tg on negative selection. Surprisingly, however, although the thymi of IL-7Rα Tg mice were comparable at birth, there was a decrease in thymocyte number as the mice aged. This was found to be due to competition between DN and IL-7R–expressing DP cells for endogenous IL-7, which resulted in decreased levels of Bcl-2 in DN cells, increased DN apoptosis, and decreased DN cell number. Therefore, the down-regulation of IL-7R on DP cells is an “altruistic” act required for maintaining an adequate supply of local IL-7 for DN cells.
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Affiliation(s)
- Ivana Munitic
- Laboratory of Immune Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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20
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Kang J, DiBenedetto B, Narayan K, Zhao H, Der SD, Chambers CA. STAT5 is required for thymopoiesis in a development stage-specific manner. THE JOURNAL OF IMMUNOLOGY 2004; 173:2307-14. [PMID: 15294943 DOI: 10.4049/jimmunol.173.4.2307] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Diverse cytokines necessary for normal lymphopoiesis and lymphocyte homeostasis activate STAT5 in responder cells. Although STAT5 has been suggested to be a central molecular effecter of IL-7 function, its essential role during IL-7-dependent T cell development in vivo remained unclear. Using Stat5(-/-) mice we now show that STAT5 is essential for various functions ascribed to IL-7 in vivo. STAT5 is required for embryonic thymocyte production, TCRgamma gene transcription, and Peyer's patch development. In sharp contrast, normal STAT5 is dispensable for adult thymopoiesis. In peripheral lymphocytes, STAT5 is primarily required for the generation and/or maintenance of gammadelta T cells and TCRgammadelta(+) intraepithelial lymphocytes. Collectively, these results demonstrate that STAT5 is critical for many, but not all, aspects of steady state lymphoid lineage development and maintenance and suggest the existence of previously undocumented cytokine signaling traits and/or cytokine milieu during adult thymopoiesis.
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Affiliation(s)
- Joonsoo Kang
- Department of Pathology, Graduate Program in Immunology and Virology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
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21
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Park JH, Yu Q, Erman B, Appelbaum JS, Montoya-Durango D, Grimes HL, Singer A. Suppression of IL7Ralpha transcription by IL-7 and other prosurvival cytokines: a novel mechanism for maximizing IL-7-dependent T cell survival. Immunity 2004; 21:289-302. [PMID: 15308108 DOI: 10.1016/j.immuni.2004.07.016] [Citation(s) in RCA: 374] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2004] [Revised: 06/15/2004] [Accepted: 06/23/2004] [Indexed: 01/08/2023]
Abstract
Survival of naive T cells is dependent upon IL-7, which is present in vivo in limiting amounts with the result that naive T cells must compete for IL-7-mediated survival signals. It would seem imperative during T cell homeostasis that limiting IL-7 be shared by the greatest possible number of T cells. We now describe a novel regulatory mechanism that specifically suppresses IL7Ralpha transcription in response to IL-7 and other prosurvival cytokines (IL-2, IL-4, IL-6, and IL-15). Consequently, IL7R expression is reduced on T cells that have received cytokine-mediated survival signals so they do not compete with unsignaled T cells for remaining IL-7. Interestingly, cytokine-mediated suppression of IL7Ralpha transcription involves different molecular mechanisms in CD4+ and CD8+ T cells, as CD8+ T cells utilize the transcriptional repressor GFI1 while CD4+ T cells do not. We suggest that this homeostatic regulatory mechanism promotes survival of the maximum possible number of T cells for the amount of IL-7 available.
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Affiliation(s)
- Jung-Hyun Park
- Experimental Immunology Branch, National Cancer Institute, Building 10 Room 4B36, Bethesda, Maryland 20892, USA
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22
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Yu Q, Erman B, Park JH, Feigenbaum L, Singer A. IL-7 receptor signals inhibit expression of transcription factors TCF-1, LEF-1, and RORgammat: impact on thymocyte development. ACTA ACUST UNITED AC 2004; 200:797-803. [PMID: 15365098 PMCID: PMC2211960 DOI: 10.1084/jem.20032183] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Intrathymic T cell development depends on signals transduced by both T cell receptor and cytokine receptors. Early CD4−CD8− (double negative) thymocytes require interleukin (IL)-7 receptor (IL-7R) signals for survival and proliferation, but IL-7R signals are normally extinguished by the immature single positive (ISP) stage of thymocyte development. We now demonstrate that IL-7R signals inhibit expression of transcription factors TCF-1, LEF-1, and RORγt that are required for the ISP to double positive (DP) transition in the thymus. In addition, we demonstrate that IL-7R signals also inhibit TCF-1 and LEF-1 expression in mature peripheral T cells. Thus, the present work has identified several important downstream target genes of IL-7R signaling in T cells and thymocytes that provide a molecular mechanism for the inhibitory influence of IL-7R signaling on DP thymocyte development. We conclude that IL-7R signals down-regulate transcription factors required for the ISP to DP transition and so must be terminated by the ISP stage of thymocyte development.
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Affiliation(s)
- Qing Yu
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bldg. 10, Rm. 4B36, Bethesda, MD 20892, USA
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23
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Van De Wiele CJ, Marino JH, Murray BW, Vo SS, Whetsell ME, Teague TK. Thymocytes between the beta-selection and positive selection checkpoints are nonresponsive to IL-7 as assessed by STAT-5 phosphorylation. THE JOURNAL OF IMMUNOLOGY 2004; 172:4235-44. [PMID: 15034036 DOI: 10.4049/jimmunol.172.7.4235] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Interleukin-7 is widely accepted as a major homeostatic factor involved in T cell development. To assess the IL-7 responsiveness of thymocytes involved in selection processes, we used a new sensitive flow cytometry-based assay to detect intracellular phosphorylation of STAT-5 induced by IL-7 in defined mouse thymocyte subsets. Using this method, we found the earliest thymocyte subset (CD4(-)CD8(-)CD25(-)CD44(+)) to contain both IL-7-responsive and nonresponsive cells. Transition through the next stages of development (CD4(-)CD8(-)CD25(+)CD44(+ and -)) was associated with responsiveness of all thymocytes within these populations. Passage of thymocytes through beta-selection resulted in a significant reduction in IL-7 sensitivity. In the next phases of development (TCR(-) and TCR(low)CD69(-)), thymocytes were completely insensitive to the effects of IL-7. STAT-5 phosphorylation in response to IL-7 was again observed, however, in thymocytes involved in the positive selection process (TCR(low)CD69(+) and TCR(intermediate)). As expected, CD4 and CD8 single-positive thymocytes were responsive to IL-7. These findings delineate an IL-7-insensitive population between the beta-selection and positive selection checkpoints encompassing thymocytes predicted to die by neglect due to failure of positive selection. This pattern of sensitivity suggests a two-signal mechanism by which survival of thymocytes at these checkpoints is governed.
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Affiliation(s)
- C Justin Van De Wiele
- Department of Surgery, University of Oklahoma College of Medicine, Tulsa, OK 74135, USA
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24
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Jiang Q, Li WQ, Hofmeister RR, Young HA, Hodge DR, Keller JR, Khaled AR, Durum SK. Distinct regions of the interleukin-7 receptor regulate different Bcl2 family members. Mol Cell Biol 2004; 24:6501-13. [PMID: 15226449 PMCID: PMC434255 DOI: 10.1128/mcb.24.14.6501-6513.2004] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2003] [Revised: 12/12/2003] [Accepted: 04/27/2004] [Indexed: 11/20/2022] Open
Abstract
The antiapoptotic function of the interleukin-7 (IL-7) receptor is related to regulation of three members of the Bcl2 family: synthesis of Bcl2, phosphorylation of Bad, and cytosolic retention of Bax. Here we show that, in an IL-7-dependent murine T-cell line, different regions of the IL-7 receptor initiate the signal transduction pathways that regulate these proteins. Both Box1 and Y449 are required to signal Bcl2 synthesis and Bax cytosolic retention. This suggests a sequential model in which Jak1, which binds to Box1, is first activated and then phosphorylates Y449, leading to Bcl2 and Bax regulation, accounting for approximately 90% of the survival function. Phosphorylation of Bad required Box1 but not Y449, suggesting that Jak1 also initiates an additional signaling cascade that accounts for approximately 10% of the survival function. Stat5 was activated from the Y449 site but only partially accounted for the survival signal. Proliferation required both Y449 and Box1. Thymocyte development in vivo showed that deletion of Y449 eliminated 90% of alphabeta T-cell development and completely eliminated gammadelta T-cell development, whereas deleting Box 1 completely eliminated both alphabeta and gammadelta T-cell development. Thus the IL-7 receptor controls at least two distinct pathways, in addition to Stat5, that are required for cell survival.
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Affiliation(s)
- Qiong Jiang
- Laboratory of Molecular Immunoregulation, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702-1201, USA
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25
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Doan LL, Kitay MK, Yu Q, Singer A, Herblot S, Hoang T, Bear SE, Morse HC, Tsichlis PN, Grimes HL. Growth factor independence-1B expression leads to defects in T cell activation, IL-7 receptor alpha expression, and T cell lineage commitment. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:2356-66. [PMID: 12594258 DOI: 10.4049/jimmunol.170.5.2356] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
T cell differentiation in the thymus is dependent upon signaling through the TCR and is characterized by the resulting changes in expression patterns of CD4 and CD8 surface coreceptor molecules. Although recent studies have characterized the effects of proximal TCR signaling on T cell differentiation, the downstream integration of these signals remains largely unknown. The growth factor independence-1 (GFI1) and GFI1B transcriptional repressors may regulate cytokine signaling pathways to affect lymphocyte growth and survival. In this study, we show that Gfi1 expression is induced upon induction of the T cell program. Gfi1B expression is low and dynamic during T cell development, but is terminated in mature thymocytes. Transgenic expression of GFI1 and GFI1B in T cells allowed us to determine the functional consequences of constitutive expression. GFI1 potentiates response to TCR stimulation and IL-2, whereas GFI1B-transgenic T cells are defective in T cell activation. Moreover, GFI1B-transgenic thymocytes display reduced expression of the late-activation marker IL-7R alpha, and a decrease in CD4(-)8(+) single-positive T cells that can be mitigated by transgenic expression of BCL2 or GFI1. These data show that GFI1 and GFI1B are functionally unique, and implicate a role for GFI1 in the integration of activation and survival signals.
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Affiliation(s)
- Loretta L Doan
- Institute for Cellular Therapeutics and Department of Surgery, University of Louisville School of Medicine, Louisville, KY 40202, USA
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26
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Min B, McHugh R, Sempowski GD, Mackall C, Foucras G, Paul WE. Neonates support lymphopenia-induced proliferation. Immunity 2003; 18:131-40. [PMID: 12530982 DOI: 10.1016/s1074-7613(02)00508-3] [Citation(s) in RCA: 230] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
T cells expand without intentional antigen stimulation when transferred into adult lymphopenic environments. In this study, we show that the physiologic lymphopenic environment existing in neonatal mice also supports CD4 T cell proliferation. Strikingly, naive CD4 T cells that proliferate within neonates acquire the phenotypic and functional characteristics of memory cells. Such proliferation is inhibited by the presence of both memory and naive CD4 T cells, is enhanced by 3-day thymectomy, is independent of IL-7, and requires a class II MHC-TCR interaction and a CD28-mediated signal. CD44(bright) CD4 T cells in neonates have a wide repertoire as judged by the distribution of Vbeta expression. Thus, lymphopenia-induced T cell proliferation is a physiologic process that occurs during the early postnatal period.
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Affiliation(s)
- Booki Min
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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27
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Abstract
In a human, about 10(11) excess peripheral lymphocytes die every day. This death process maintains a constant lymphocyte population size in the face of a continuous influx of new lymphocytes and the homeostatic proliferation of old ones. Death is triggered when a lymphocyte fails to acquire signals from survival factors, the availability of which, therefore, determines the size of the pool of lymphocytes. A lymphocyte acquires survival signals through receptors for cytokines, antigens, hormones and probably other extracellular factors. Here, we discuss current concepts of the intracellular signalling pathways for survival versus death that establish cytokine-regulated lymphocyte homeostasis.
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Affiliation(s)
- Annette R Khaled
- Laboratory of Molecular Immunoregulation, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702-1201, USA
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28
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Su DM, Manley NR. Stage-specific changes in fetal thymocyte proliferation during the CD4-8- to CD4+8+ transition in wild type, Rag1-/-, and Hoxa3,Pax1 mutant mice. BMC Immunol 2002; 3:12. [PMID: 12241558 PMCID: PMC130029 DOI: 10.1186/1471-2172-3-12] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2002] [Accepted: 09/19/2002] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND The function of the thymic microenvironment is to promote thymocyte maturation, in part via regulation of thymocyte proliferation and cell death. Defects in fetal thymic epithelial cell (TEC) development and function, and therefore in the formation of a functional microenvironment, can be caused either directly by TEC differentiation defects or indirectly by defective thymocyte maturation. In this paper we studied fetal thymocyte proliferation during the early transition from the CD3-4-8- (triple negative, TN) to CD4+8+ (double positive, DP) stages. We compared wild type mice with Rag1-/- mice and with Hoxa3+/-Pax1-/- compound mutant mice, which have blocks at different stages of thymocyte development. RESULTS Wild type fetal and adult thymus showed stage-specific differences in the proliferation profiles of developing thymocytes, with fetal stages showing generally higher levels of proliferation. The proliferation profile of fetal thymocytes from Rag1-/- mutants also had stage-specific increases in proliferation compared to wild type fetal thymocytes, in contrast to the lower proliferation previously reported for thymocytes from adult Rag1-/- mutants. We have previously shown that Hoxa3+/-Pax1-/- mice have abnormal fetal TEC development, resulting in increased apoptosis at the TN to DP transition and decreased DP cell numbers. Fetal thymocytes from Hoxa3+/-Pax1-/- compound mutants had increased proliferation, but fewer proliferating cells, at the DP stage. We also observed a decrease in the level of the cytokines IL-7 and SCF produced by Hoxa3+/-Pax1-/-TECs. CONCLUSION Our results indicate complex and stage-specific effects of abnormal TEC development on thymocyte proliferation.
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Affiliation(s)
- Dong-ming Su
- Department of Genetics, University of Georgia, Athens, Georgia 30602 USA
| | - Nancy R Manley
- Department of Genetics, University of Georgia, Athens, Georgia 30602 USA
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29
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Goldrath AW, Sivakumar PV, Glaccum M, Kennedy MK, Bevan MJ, Benoist C, Mathis D, Butz EA. Cytokine requirements for acute and Basal homeostatic proliferation of naive and memory CD8+ T cells. J Exp Med 2002; 195:1515-22. [PMID: 12070279 PMCID: PMC2193554 DOI: 10.1084/jem.20020033] [Citation(s) in RCA: 438] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Both naive and memory T cells undergo antigen-independent proliferation after transfer into a T cell-depleted environment (acute homeostatic proliferation), whereas only memory T cells slowly divide in a full T cell compartment (basal proliferation). We show, first, that naive and memory CD8+ T cells have different cytokine requirements for acute homeostatic proliferation. Interleukin (IL)-7 receptor(R)alpha-mediated signals were obligatory for proliferation of naive T cells in lymphopenic hosts, whereas IL-15 did not influence their division. Memory T cells, on the other hand, could use either IL-7Ralpha- or IL-15-mediated signals for acute homeostatic proliferation: their proliferation was delayed when either IL-7Ralpha was blocked or IL-15 removed, but only when both signals were absent was proliferation ablated. Second, the cytokine requirements for basal and acute homeostatic proliferation of CD8+ memory T cells differ, as basal division of memory T cells was blocked completely in IL-15-deficient hosts. These data suggest a possible mechanism for the dearth of memory CD8+ T cells in IL-15- and IL-15Ralpha-deficient mice is their impaired basal proliferation. Our results show that naive and memory T lymphocytes differ in their cytokine dependence for acute homeostatic proliferation and that memory T lymphocytes have distinct requirements for proliferation in full versus empty compartments.
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Affiliation(s)
- Ananda W Goldrath
- Section on Immunology and Immunogenetics, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA.
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30
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Sahali D, Pawlak A, Valanciuté A, Grimbert P, Lang P, Remy P, Bensman A, Guellën G. A novel approach to investigation of the pathogenesis of active minimal-change nephrotic syndrome using subtracted cDNA library screening. J Am Soc Nephrol 2002; 13:1238-1247. [PMID: 11961011 DOI: 10.1681/asn.v1351238] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Clinical and experimental observations suggest that minimal-change nephrotic syndrome (MCNS) results from T cell dysfunction, via unknown mechanisms. For the identification of genes that are potentially involved in MCNS, a subtractive cDNA library was constructed from cDNA from T cell-enriched peripheral blood mononuclear cells obtained from the same patient during relapse versus remission ("relapse minus remission"). This library was screened by differential hybridization with forward ("relapse minus remission") and reverse ("remission minus relapse") subtractive cDNAs probes, as well as unsubtracted probes from relapse and remission, and irrelevant nephrotic syndrome (membranous nephropathy). A total of 84 transcripts were isolated, of which 12 matched proteins of unknown function and 30 were unknown clones. Among the 42 known transcripts, at least 18 are closely involved in the T cell receptor-mediated complex signaling cascade, including genes encoding components of the T cell receptor and proteins associated with the cytoskeletal scaffold, as well as transcription factors. In particular, it was demonstrated that the expression levels of Fyb/Slap, L-plastin, and grancalcin were increased during relapse, suggesting that the integration of proximal signaling after T cell engagement involves the preferential recruitment of these cytoskeleton-associated proteins in MCNS. Because very low levels of interleukin-12 receptor beta2 mRNA were detected in relapse samples, the interleukin-12 signaling pathway might be defective, suggesting that, in MCNS, T cell activation evolves toward a T helper 2 phenotype. Therefore, the combination of subtractive cloning and differential screening constitutes an efficient approach to the identification of genes that are likely to be involved in the pathophysiologic processes of MCNS.
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Affiliation(s)
- Djillali Sahali
- *INSERM Unit 99, Upress B JE 2129, and Adult Nephrology Service, Henri Mondor Hospital, University of Paris XII, Créteil, France, and Pediatric Nephrology Service, Armand Trousseau Hospital AP-HP, Paris, France
- *INSERM Unit 99, Upress B JE 2129, and Adult Nephrology Service, Henri Mondor Hospital, University of Paris XII, Créteil, France, and Pediatric Nephrology Service, Armand Trousseau Hospital AP-HP, Paris, France
| | - André Pawlak
- *INSERM Unit 99, Upress B JE 2129, and Adult Nephrology Service, Henri Mondor Hospital, University of Paris XII, Créteil, France, and Pediatric Nephrology Service, Armand Trousseau Hospital AP-HP, Paris, France
| | - Asta Valanciuté
- *INSERM Unit 99, Upress B JE 2129, and Adult Nephrology Service, Henri Mondor Hospital, University of Paris XII, Créteil, France, and Pediatric Nephrology Service, Armand Trousseau Hospital AP-HP, Paris, France
| | - Philippe Grimbert
- *INSERM Unit 99, Upress B JE 2129, and Adult Nephrology Service, Henri Mondor Hospital, University of Paris XII, Créteil, France, and Pediatric Nephrology Service, Armand Trousseau Hospital AP-HP, Paris, France
| | - Philippe Lang
- *INSERM Unit 99, Upress B JE 2129, and Adult Nephrology Service, Henri Mondor Hospital, University of Paris XII, Créteil, France, and Pediatric Nephrology Service, Armand Trousseau Hospital AP-HP, Paris, France
- *INSERM Unit 99, Upress B JE 2129, and Adult Nephrology Service, Henri Mondor Hospital, University of Paris XII, Créteil, France, and Pediatric Nephrology Service, Armand Trousseau Hospital AP-HP, Paris, France
| | - Philippe Remy
- *INSERM Unit 99, Upress B JE 2129, and Adult Nephrology Service, Henri Mondor Hospital, University of Paris XII, Créteil, France, and Pediatric Nephrology Service, Armand Trousseau Hospital AP-HP, Paris, France
| | - Albert Bensman
- *INSERM Unit 99, Upress B JE 2129, and Adult Nephrology Service, Henri Mondor Hospital, University of Paris XII, Créteil, France, and Pediatric Nephrology Service, Armand Trousseau Hospital AP-HP, Paris, France
- *INSERM Unit 99, Upress B JE 2129, and Adult Nephrology Service, Henri Mondor Hospital, University of Paris XII, Créteil, France, and Pediatric Nephrology Service, Armand Trousseau Hospital AP-HP, Paris, France
| | - Georges Guellën
- *INSERM Unit 99, Upress B JE 2129, and Adult Nephrology Service, Henri Mondor Hospital, University of Paris XII, Créteil, France, and Pediatric Nephrology Service, Armand Trousseau Hospital AP-HP, Paris, France
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31
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Abstract
Lymphocyte numbers and subset composition are maintained at relatively constant levels throughout adulthood. Fluctuations in cell numbers due to infection, loss of cells, or other influences are smoothed out by unknown mechanisms that return the system to homeostasis. Regulation of lymphocyte numbers could be controlled at several points: rate of production, alteration in life span by diminution or enhancement of survival, or by division of cells within the compartment. Cell numbers within the immune system appear to be controlled by homeostatic mechanisms that influence each of these points. This discussion will focus on the regulation of peripheral cell numbers by the antigen-independent proliferation of T cells, which has recently been demonstrated to contribute to the maintenance and recovery of lymphocyte homeostasis.
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Affiliation(s)
- Ananda W Goldrath
- Joslin Diabetes Center, Department of Immunology, Harvard Medical School, 1 Joslin Place, Boston, MA 02115, USA.
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32
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Ye SK, Maki K, Lee HC, Ito A, Kawai K, Suzuki H, Mak TW, Chien Y, Honjo T, Ikuta K. Differential roles of cytokine receptors in the development of epidermal gamma delta T cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:1929-34. [PMID: 11489972 DOI: 10.4049/jimmunol.167.4.1929] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
IL-7 and IL-15 play important roles in gammadelta T cell development. These receptors transmit proliferation and/or survival signals in gammadelta T cells. In addition, the IL-7R promotes recombination and transcription in the TCR gamma locus. To clarify the role of the cytokine receptors in the development of epidermal gammadelta T cells, we introduced a Vgamma3/Vdelta1 TCR transgene, derived from Thy-1+ dendritic epidermal T cells (DETC), into IL-7Ralpha-deficient mice, and we found that they partly rescued gammadelta T cells in the adult thymus but not in the spleen. Introduction of an additional Bcl-2 transgene had a minimal effect on gammadelta T cells in the adult thymus of these mice. In contrast to the adult thymus, the introduction of the Vgamma3/Vdelta1 TCR transgene into IL-7Ralpha-/- mice completely restored Vgamma3+ T cells in the fetal thymus and DETC in the adult skin. On the contrary, the same Vgamma3/Vdelta1 TCR transgene failed to rescue DETC in the skin of IL-2Rbeta-deficient mice, even with the additional Bcl-2 transgene. These results suggest that the IL-2/IL-15R, rather than the IL-7R, plays an essential role in proliferation and survival of DETC in the fetal thymus and the skin. In contrast, the IL-7R is probably essential in the induction of V-J recombination of TCRgamma genes. Thus, this study proves that IL-7R and IL-2/IL-15R serve differential functions in epidermal gammadelta T cell development.
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MESH Headings
- Aging/genetics
- Aging/immunology
- Animals
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cell Survival/genetics
- Cell Survival/immunology
- Crosses, Genetic
- Epidermal Cells
- Epidermis/immunology
- Epidermis/metabolism
- Fetus/cytology
- Fetus/immunology
- Fetus/metabolism
- Langerhans Cells/immunology
- Langerhans Cells/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Receptors, Antigen, T-Cell, gamma-delta/genetics
- Receptors, Cytokine/physiology
- Receptors, Interleukin-7/deficiency
- Receptors, Interleukin-7/genetics
- Skin/cytology
- Skin/immunology
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Thymus Gland/cytology
- Thymus Gland/immunology
- Thymus Gland/metabolism
- Transgenes/immunology
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Affiliation(s)
- S K Ye
- Department of Medical Chemistry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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