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Interleukin-7 and Immunosenescence. J Immunol Res 2017; 2017:4807853. [PMID: 28484723 PMCID: PMC5397725 DOI: 10.1155/2017/4807853] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/01/2017] [Accepted: 02/19/2017] [Indexed: 12/21/2022] Open
Abstract
The age of an individual is an important, independent risk factor for many of the most common diseases afflicting modern societies. Interleukin-7 (IL-7) plays a central, critical role in the homeostasis of the immune system. Recent studies support a critical role for IL-7 in the maintenance of a vigorous healthspan. We describe the role of IL-7 and its receptor in immunosenescence, the aging of the immune system. An understanding of the role that IL-7 plays in aging may permit parsimonious preventative or therapeutic solutions for diverse conditions. Perhaps IL-7 might be used to "tune" the immune system to optimize human healthspan and longevity.
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Tsagaratou A, Grammenoudi S, Mosialos G. Differential requirement of IKK2 for CYLD-dependent representation of thymic and peripheral T-cell populations. Eur J Immunol 2011; 41:3054-62. [DOI: 10.1002/eji.201041160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 04/21/2011] [Accepted: 06/27/2011] [Indexed: 01/09/2023]
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3
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Morrot A, Terra-Granado E, Pérez AR, Silva-Barbosa SD, Milićević NM, Farias-de-Oliveira DA, Berbert LR, De Meis J, Takiya CM, Beloscar J, Wang X, Kont V, Peterson P, Bottasso O, Savino W. Chagasic thymic atrophy does not affect negative selection but results in the export of activated CD4+CD8+ T cells in severe forms of human disease. PLoS Negl Trop Dis 2011; 5:e1268. [PMID: 21858238 PMCID: PMC3156684 DOI: 10.1371/journal.pntd.0001268] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 06/21/2011] [Indexed: 11/19/2022] Open
Abstract
Extrathymic CD4+CD8+ double-positive (DP) T cells are increased in some pathophysiological conditions, including infectious diseases. In the murine model of Chagas disease, it has been shown that the protozoan parasite Trypanosoma cruzi is able to target the thymus and induce alterations of the thymic microenvironment and the lymphoid compartment. In the acute phase, this results in a severe atrophy of the organ and early release of DP cells into the periphery. To date, the effect of the changes promoted by the parasite infection on thymic central tolerance has remained elusive. Herein we show that the intrathymic key elements that are necessary to promote the negative selection of thymocytes undergoing maturation during the thymopoiesis remains functional during the acute chagasic thymic atrophy. Intrathymic expression of the autoimmune regulator factor (Aire) and tissue-restricted antigen (TRA) genes is normal. In addition, the expression of the proapoptotic Bim protein in thymocytes was not changed, revealing that the parasite infection-induced thymus atrophy has no effect on these marker genes necessary to promote clonal deletion of T cells. In a chicken egg ovalbumin (OVA)-specific T-cell receptor (TCR) transgenic system, the administration of OVA peptide into infected mice with thymic atrophy promoted OVA-specific thymocyte apoptosis, further indicating normal negative selection process during the infection. Yet, although the intrathymic checkpoints necessary for thymic negative selection are present in the acute phase of Chagas disease, we found that the DP cells released into the periphery acquire an activated phenotype similar to what is described for activated effector or memory single-positive T cells. Most interestingly, we also demonstrate that increased percentages of peripheral blood subset of DP cells exhibiting an activated HLA-DR+ phenotype are associated with severe cardiac forms of human chronic Chagas disease. These cells may contribute to the immunopathological events seen in the Chagas disease. The thymus is a primary lymphoid organ that plays an important role on the development of the immune system and maturation of the T cell repertoire. During the normal life span, this organ undergoes involution during the aging and also in the presence of a wide variety of infectious diseases. It has been shown that the protozoan parasite Trypanosoma cruzi is able to target the thymus and induce alterations of the thymic microenvironment. In the acute phase, this results in a severe atrophy of the organ and early release of immature double-positive (DP) T cells into the periphery. The effect of the changes promoted by the parasite infection on thymic central tolerance has remained not clear. The present study shows that the intrathymic key elements that promote the negative selection of thymocytes during the thymopoiesis remains functional in the acute chagasic thymic atrophy. However, we found that the DP cells released into the periphery acquire an activated phenotype and its high frequency in the peripheral blood are associated with severe cardiac forms of human chronic Chagas disease.
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Affiliation(s)
- Alexandre Morrot
- Department of Immunology, Microbiology Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
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4
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Wu ZP, Bilousova T, Escande-Beillard N, Dang H, Hsieh T, Tian J, Kaufman DL. Major histocompatibility complex class I-mediated inhibition of neurite outgrowth from peripheral nerves. Immunol Lett 2011; 135:118-23. [PMID: 20974178 PMCID: PMC5776043 DOI: 10.1016/j.imlet.2010.10.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 10/14/2010] [Accepted: 10/17/2010] [Indexed: 10/18/2022]
Abstract
Studies of mice deficient in classical major histocompatability complex class I (MHCI) revealed that MHCI plays an important role in neurodevelopment in the central nervous system. We previously studied the effects of recombinant MHCI molecules on wildtype retina explants and observed that MHCI can inhibit retina neurite outgrowth, with self-MHCI molecules having greater inhibitory effect than non-self MHCI molecules. Here, we examined classical MHCI's effects on axon outgrowth from neurons of the peripheral nervous system (PNS). We used the embryonic dorsal root ganglia (DRG) explant model since their neurons express MHCI and because DRG explants have been widely used to assess the effects of molecules on axonal outgrowth from PNS neurons. We observed that picomolar levels of a recombinant self-MHCI molecule, but not non-self MHCI molecules, inhibited axon outgrowth from DRG explants. This differential sensitivity to self- vs. non-self MHCI suggests that early in development, self-MHCI may "educate" PNS neurons to express appropriate MHCI receptors, as occurs during natural killer cell development. Furthermore, we observed that a MHCI tetramer stained embryonic DRG neurons, indicating the expression of classical MHCI receptors. These results suggest that MHCI and MHCI receptors play roles during early stages of PNS development and may provide new targets of therapeutic strategies to promote neuronal outgrowth after PNS injury.
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Affiliation(s)
- Zhongqi-Phyllis Wu
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA, 90024, USA
- Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA, 90024, USA
| | - Tina Bilousova
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA, 90024, USA
| | - Nathalie Escande-Beillard
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA, 90024, USA
| | - Hoa Dang
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA, 90024, USA
| | - Terry Hsieh
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA, 90024, USA
| | - Jide Tian
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA, 90024, USA
| | - Daniel L. Kaufman
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA, 90024, USA
- Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA, 90024, USA
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5
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Alexandropoulos K, Regelmann AG. Regulation of T-lymphocyte physiology by the Chat-H/CasL adapter complex. Immunol Rev 2010; 232:160-74. [PMID: 19909363 DOI: 10.1111/j.1600-065x.2009.00831.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The Cas family of proteins consists of at least four members implicated in the regulation of diverse cellular processes such as cell proliferation, adhesion, motility, and cancer cell metastasis. Cas family members have conserved C-termini that mediate constitutive heterotypic interactions with members of a different group of proteins, the NSP family. Both the Cas and NSP proteins have conserved domains that mediate protein-protein interactions with other cytoplasmic intermediates. Signaling modules assembled by these proteins in turn regulate signal transduction downstream of a variety of receptors including integrin, chemokine, and antigen receptors. T lymphocytes express the NSP protein NSP3/Chat-H and the Cas protein Hef1/CasL, which are found in a constitutive complex in naive T cells. We recently showed that Chat-H and Hef1/CasL regulate integrin-mediated adhesion and promote T-cell migration and trafficking downstream of activated chemokine receptors. It is currently unclear if the Chat-H/CasL module also plays a role in antigen receptor signaling. Here we review our current knowledge of how Chat-H and Hef1/CasL regulate T-cell physiology and whether this protein complex plays a functional role downstream of T-cell receptor activation.
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Affiliation(s)
- Konstantina Alexandropoulos
- Department of Medicine, Division of Clinical Immunology, The Immunology Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.
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6
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Chong MMW, Simpson N, Ciofani M, Chen G, Collins A, Littman DR. Epigenetic propagation of CD4 expression is established by the Cd4 proximal enhancer in helper T cells. Genes Dev 2010; 24:659-69. [PMID: 20360383 DOI: 10.1101/gad.1901610] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The stability of a lineage program (cellular memory) is dependent on mechanisms that epigenetically maintain active or repressed states of gene expression (transcriptional memory). Although epigenetic silencing of genes has been clearly demonstrated from yeast to mammals, heritable maintenance of active transcription has been less clearly defined. To investigate the potential role of active transcriptional memory during lineage diversification, we employed targeted mutation of a positive-acting cis element in the Cd4 locus to determine the impact on CD4 expression and the differentiation of CD4(+) helper T cells in mice. We show that the proximal enhancer (E4(P)) of Cd4 is essential for CD4 expression in immature CD4(+)8(+) thymocytes. Furthermore, its loss resulted in reduced and unstable expression of CD4 in mature T cells. However, if the enhancer was deleted after cells had already committed to the helper T-cell lineage, CD4 expression remained high and was stable upon cell division. "Active" histone modifications, once initiated by E4(P), were also propagated independently of the enhancer. Thus, E4(P) is responsible for establishing an epigenetically inherited active Cd4 locus in the helper T-cell lineage. To our knowledge, this is the first genetic demonstration of active transcriptional memory in mammalian cells.
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Affiliation(s)
- Mark M W Chong
- The Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York 10016, USA
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7
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Escande-Beillard N, Washburn L, Zekzer D, Wu ZP, Eitan S, Ivkovic S, Lu Y, Dang H, Middleton B, Bilousova TV, Yoshimura Y, Evans CJ, Joyce S, Tian J, Kaufman DL. Neurons preferentially respond to self-MHC class I allele products regardless of peptide presented. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2010; 184:816-23. [PMID: 20018625 PMCID: PMC2997386 DOI: 10.4049/jimmunol.0902159] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Studies of mice lacking MHC class I (MHC I)-associated proteins have demonstrated a role for MHC I in neurodevelopment. A central question arising from these observations is whether neuronal recognition of MHC I has specificity for the MHC I allele product and the peptide presented. Using a well-established embryonic retina explant system, we observed that picomolar levels of a recombinant self-MHC I molecule inhibited neurite outgrowth. We then assessed the neurobiological activity of a panel of recombinant soluble MHC Is, consisting of different MHC I heavy chains with a defined self- or nonself-peptide presented, on cultured embryonic retinas from mice with different MHC I haplotypes. We observed that self-MHC I allele products had greater inhibitory neuroactivity than nonself-MHC I molecules, regardless of the nature of the peptide presented, a pattern akin to MHC I recognition by some innate immune system receptors. However, self-MHC I molecules had no effect on retinas from MHC I-deficient mice. These observations suggest that neuronal recognition of MHC I may be coordinated with the inherited MHC I alleles, as occurs in the innate immune system. Consistent with this notion, we show that MHC I and MHC I receptors are coexpressed by precursor cells at the earliest stages of retina development, which could enable such coordination.
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Affiliation(s)
- Nathalie Escande-Beillard
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90024, USA
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8
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Protein phosphatase subunit G5PR that regulates the JNK-mediated apoptosis signal is essential for the survival of CD4 and CD8 double-positive thymocytes. Mol Immunol 2008; 45:2028-37. [DOI: 10.1016/j.molimm.2007.10.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2007] [Revised: 10/11/2007] [Accepted: 10/12/2007] [Indexed: 11/22/2022]
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9
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Middlebrook AJ, Lebsack T, DeLuca D. TNF-α mediated modulation of T cell development and exacerbation of in vitro T1DM in fetal thymus organ culture. J Autoimmun 2007; 29:134-45. [PMID: 17716860 DOI: 10.1016/j.jaut.2007.06.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Revised: 06/20/2007] [Accepted: 06/20/2007] [Indexed: 12/21/2022]
Abstract
TNF-alpha is a pleiotropic cytokine that is constitutively expressed in the thymus. This cytokine has opposing effects on type 1 diabetes mellitus (T1DM) as non-obese diabetic (NOD) mice administered TNF-alpha early in life experience an acceleration in disease onset while TNF-alpha administered to adult NOD mice are rescued from disease entirely. Using fetal thymus organ culture (FTOC) as a model of T cell development and an associated in vitro T1DM model, we set out to reconcile the role of TNF-alpha in thymic development with its role in the pathogenesis of T1DM. Our data indicate that NOD derived FTOC produce a smaller percentage of double negative (CD4(-)/CD8(-)) thymocytes expressing TNF receptors compared to non-diabetic C57BL/6 (B6) derived FTOC. NOD FTOC produce more TNF-alpha than B6 FTOC during days 6-9 of culture, a time when negative selection of T cells is known to occur. Neutralization of this endogenous TNF-alpha production in NOD derived FTOC with soluble TNF receptor (sTNF R1) rescued insulin production in our in vitro T1DM model. Flow cytometric analysis of NOD FTOC treated with recombinant TNF-alpha (rTNF-alpha) or sTNF R1 demonstrated that the relative levels of TNF-alpha in the culture during the selection window (days 6-9) influence the ratio of immature vs. mature T cells that emerge from FTOC.
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MESH Headings
- Animals
- CD4 Antigens/immunology
- CD4 Antigens/metabolism
- CD8 Antigens/immunology
- CD8 Antigens/metabolism
- Diabetes Mellitus, Type 1/immunology
- Diabetes Mellitus, Type 1/metabolism
- Fetus
- Insulin/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Organ Culture Techniques
- Receptors, Tumor Necrosis Factor, Type I/metabolism
- Receptors, Tumor Necrosis Factor, Type I/pharmacology
- Receptors, Tumor Necrosis Factor, Type II/metabolism
- Recombinant Proteins/pharmacology
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Thymus Gland/embryology
- Thymus Gland/immunology
- Thymus Gland/metabolism
- Tumor Necrosis Factor-alpha/metabolism
- Tumor Necrosis Factor-alpha/pharmacology
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Affiliation(s)
- Aaron J Middlebrook
- Department of Microbiology and Immunology, University of Arizona College of Medicine, Tucson, AZ 85274, USA.
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10
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Abstract
The spleen tyrosine kinase (Syk) and ζ-associated protein of 70 kD (ZAP-70) tyrosine kinases are both expressed during early thymocyte development, but their unique thymic functions have remained obscure. No specific role for Syk during β-selection has been established, and no role has been described for ZAP-70 before positive selection. We show that Syk and ZAP-70 provide thymocytes with unique and separable fitness advantages during early development. Syk-deficient, but not ZAP-70–deficient, thymocytes are specifically impaired in initial pre-TCR signaling at the double-negative (DN) 3 β selection stage and show reduced cell-cycle entry. Surprisingly, and despite overlapping expression of both kinases, only ZAP-70 appears to promote sustained pre-TCR/TCR signaling during the DN4, immature single-positive, and double-positive stages of development before thymic selection occurs. ZAP-70 promotes survival and cell-cycle progression of developing thymocytes before positive selection, as also shown by in vivo anti-CD3 treatment of recombinase-activating gene 1–deficient mice. Our results establish a temporal separation of Syk family kinase function during early thymocyte development and a novel role for ZAP-70. We propose that pre-TCR signaling continues during DN4 and later stages, with ZAP-70 dynamically replacing Syk for continued pre-TCR signaling.
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Affiliation(s)
- Emil H Palacios
- Department of Medicine, the Rosalind Russell Medical Research Center for Arthritis, University of California-San Francisco, San Francisco, CA 94143, USA
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11
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Riera-Sans L, Behrens A. Regulation of alphabeta/gammadelta T cell development by the activator protein 1 transcription factor c-Jun. THE JOURNAL OF IMMUNOLOGY 2007; 178:5690-700. [PMID: 17442952 DOI: 10.4049/jimmunol.178.9.5690] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
c-Jun is a member of the AP-1 family of transcription factors, the activity of which is strongly augmented by TCR signaling. To elucidate the functions of c-Jun in mouse thymic lymphopoiesis, we conditionally inactivated c-Jun specifically during early T cell development. The loss of c-Jun resulted in enhanced generation of gammadelta T cells, whereas alphabeta T cell development was partially arrested at the double-negative 3 stage. The increased generation of gammadelta T cells by loss of c-Jun was cell autonomous, because in a competitive reconstitution experiment the knockout-derived cells produced more gammadelta T cells than did the control cells. C-jun-deficient immature T cells failed to efficiently repress transcription of IL-7Ralpha, resulting in augmented IL-7Ralpha mRNA and surface levels. Chromatin immunoprecipitation assays revealed binding of c-Jun to AP-1 binding sites present in the IL-7Ralpha promoter, indicating direct transcriptional regulation. Thus, c-Jun controls the transcription of IL-7Ralpha and is a novel regulator of the alphabeta/gammadelta T cell development.
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MESH Headings
- Animals
- Cell Differentiation/genetics
- Cell Lineage/genetics
- Gene Expression Regulation, Developmental
- Integrases/genetics
- Mice
- Mice, Knockout
- Proto-Oncogene Proteins c-jun/genetics
- Proto-Oncogene Proteins c-jun/physiology
- Receptors, Antigen, T-Cell, alpha-beta/analysis
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Receptors, Antigen, T-Cell, gamma-delta/analysis
- Receptors, Antigen, T-Cell, gamma-delta/immunology
- Receptors, Interleukin-7/genetics
- T-Lymphocytes/chemistry
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
- Thymus Gland/cytology
- Thymus Gland/immunology
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Affiliation(s)
- Lluís Riera-Sans
- London Research Institute, Cancer Research, Mammalian Genetics Laboratory, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London, UK
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12
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Abstract
Apoptosis is a conserved genetic program critical for the development and homeostasis of the immune system. During the early stages of lymphopoiesis, growth factor signaling is an essential regulator of homeostasis by regulating the survival of lymphocyte progenitors. During differentiation, apoptosis ensures that lymphocytes express functional antigen receptors and is essential for eliminating lymphocytes with dangerous self-reactive specificities. Many of these critical cell death checkpoints during immune development are regulated by the BCL-2 family of proteins, which is comprised of both pro- and antiapoptotic members, and members of the tumor necrosis factor death receptor family. Aberrations in the expression or function of these cell death modulators can result in pathological conditions including immune deficiency, autoimmunity, and cancer. This review will describe how apoptosis regulates these critical control points during immune development.
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Affiliation(s)
- J T Opferman
- Department of Biochemistry, St. Jude Children's Research Hospital, 332 N Lauderdale Street D-4063C, Memphis, TN 38105, USA.
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13
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Abstract
It is now becoming apparent that the immune system undergoes age-associated alterations, which accumulate to produce a progressive deterioration in the ability to respond to infections and to develop immunity after vaccination, both of which are associated with a higher mortality rate in the elderly. Immunosenescence, defined as the changes in the immune system associated with age, has been gathering interest in the scientific and health-care sectors alike. The rise in its recognition is both pertinent and timely given the increasing average age and the corresponding failure to increase healthy life expectancy. This review attempts to highlight the age-dependent defects in the innate and adaptive immune systems. While discussing the mechanisms that contribute to immunosenescence, with emphasis on the extrinsic factors, particular attention will be focused on thymic involution. Finally, we illuminate potential therapies that could be employed to help us live a longer, fuller and healthier life.
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Affiliation(s)
- Danielle Aw
- Royal Veterinary College, Host Response and Genes and Development Group, Department of Veterinary Basic Sciences, Royal College Street, London, United Kingdom
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14
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Atherly LO, Lucas JA, Felices M, Yin CC, Reiner SL, Berg LJ. The Tec family tyrosine kinases Itk and Rlk regulate the development of conventional CD8+ T cells. Immunity 2006; 25:79-91. [PMID: 16860759 DOI: 10.1016/j.immuni.2006.05.012] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 04/24/2006] [Accepted: 05/05/2006] [Indexed: 10/24/2022]
Abstract
The Tec family tyrosine kinases, Itk and Rlk, are expressed in thymocytes and peripheral T cells and regulate thresholds of T cell receptor signaling. Yet little is known about the specific role of Itk- and Rlk-dependent signals in CD8(+) T cell maturation. We show here that Itk(-/-) and Rlk(-/-)Itk(-/-) mice were nearly devoid of conventional CD8(+) T cells and, instead, contained a large population of CD8(+) T cells that bear striking similarity to lineages of innate lymphocytes. Itk(-/-) and Rlk(-/-)Itk(-/-) CD8(+) thymocytes and T cells were CD44(hi), CD122(+), and NK1.1(+); were able to produce interferon-gamma directly ex vivo; and were dependent on interleukin-15. Itk(-/-) and Rlk(-/-)Itk(-/-) CD8(+) thymocytes expressed abundant transcripts for the T box transcription factor, eomesodermin, correlating with their phenotype and function. These data indicate a critical role for Itk and Rlk in conventional CD8(+) T cell development in the thymus.
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Affiliation(s)
- Luana O Atherly
- Department of Pathology, University of Massachusetts Medical School, Worcester, 01655, USA
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15
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Franco CB, Scripture-Adams DD, Proekt I, Taghon T, Weiss AH, Yui MA, Adams SL, Diamond RA, Rothenberg EV. Notch/Delta signaling constrains reengineering of pro-T cells by PU.1. Proc Natl Acad Sci U S A 2006; 103:11993-8. [PMID: 16880393 PMCID: PMC1567686 DOI: 10.1073/pnas.0601188103] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PU.1 is essential for early stages of mouse T cell development but antagonizes it if expressed constitutively. Two separable mechanisms are involved: attenuation and diversion. Dysregulated PU.1 expression inhibits pro-T cell survival, proliferation, and passage through beta-selection by blocking essential T cell transcription factors, signaling molecules, and Rag gene expression, which expression of a rearranged T cell antigen receptor transgene cannot rescue. However, Bcl2 transgenic cells are protected from this attenuation and may even undergo beta-selection, as shown by PU.1 transduction of defined subsets of Bcl2 transgenic fetal thymocytes with differentiation in OP9-DL1 and OP9 control cultures. The outcome of PU.1 expression in these cells depends on Notch/Delta signaling. PU.1 can efficiently divert thymocytes toward a myeloid-like state with multigene regulatory changes, but Notch/Delta signaling vetoes diversion. Gene expression analysis distinguishes sets of critical T lineage regulatory genes with different combinatorial responses to PU.1 and Notch/Delta signals, suggesting particular importance for inhibition of E proteins, Myb, and/or Gfi1 (growth factor independence 1) in diversion. However, Notch signaling only protects against diversion of cells that have undergone T lineage specification after Thy-1 and CD25 up-regulation. The results imply that in T cell precursors, Notch/Delta signaling normally acts to modulate and channel PU.1 transcriptional activities during the stages from T lineage specification until commitment.
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Affiliation(s)
- Christopher B. Franco
- *Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125; and
| | | | - Irina Proekt
- M.D.–Ph.D. Program, University of Southern California–California Institute of Technology, Los Angeles, CA 90233
| | - Tom Taghon
- *Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125; and
| | - Angela H. Weiss
- *Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125; and
| | - Mary A. Yui
- *Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125; and
| | - Stephanie L. Adams
- *Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125; and
| | - Rochelle A. Diamond
- *Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125; and
| | - Ellen V. Rothenberg
- *Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125; and
- **To whom correspondence should be addressed. E-mail:
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16
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Dragone LL, Myers MD, White C, Sosinowski T, Weiss A. Src-Like Adaptor Protein Regulates B Cell Development and Function. THE JOURNAL OF IMMUNOLOGY 2005; 176:335-45. [PMID: 16365426 DOI: 10.4049/jimmunol.176.1.335] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The avidity of BCRs and TCRs influences signal strength during processes of lymphocyte development. Avidity is determined by both the intrinsic affinity for Ag and surface levels of the Ag receptor. The Src-like adaptor protein (SLAP) is a regulator of TCR levels on thymocytes, and its deficiency alters thymocyte development. We hypothesized that SLAP, which is expressed in B cells, also is important in regulating BCR levels, signal strength, and B cell development. To test this hypothesis, we analyzed the B cell compartment in SLAP-deficient mice. We found increased splenic B cell numbers and decreased surface IgM levels on mature, splenic B cells deficient in SLAP. Immature bone marrow and splenic B cells from BCR-transgenic, SLAP-deficient mice were found to express higher surface levels of IgM. In contrast, mature splenic B cells from BCR-transgenic mice expressed decreased levels of surface BCR associated with decreased calcium flux and activation-induced markers, compared with controls. These data suggest that SLAP regulates BCR levels and signal strength during lymphocyte development.
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Affiliation(s)
- Leonard L Dragone
- Division of Pediatric Immunology/Rheumatology, Department of Pediatrics, University of California, San Francisco, CA 94143, USA
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17
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Béné MC. Immunophenotyping of acute leukaemias. Immunol Lett 2005; 98:9-21. [PMID: 15790504 DOI: 10.1016/j.imlet.2004.10.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2004] [Revised: 10/16/2004] [Accepted: 10/17/2004] [Indexed: 11/17/2022]
Abstract
Progress in the management and understanding of acute leukaemia can only be obtained if these diseases are thoroughly investigated, both clinically and with a series of biological tools. This alone has made and still will make possible the identification of prognostic factors and of useful markers for the follow-up of patients in remission. Among the variety of approaches of acute leukaemia definition, immunophenotyping has taken over the past 25 years a predominant and now well-defined place, although room is left for further improvement. In this review, the current state-of-the-art of immunophenotyping of acute leukaemias will be replaced in the context of physiological leukocyte maturation. The recognized classifications and recommended immunophenotyping panels will then be discussed, and the clinical relevance of several key features will be presented. Finally, more recent openings for the use of immunophenotyping will be evoked.
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Affiliation(s)
- Marie C Béné
- Laboratoire d'Immunologie du CHU, Faculté de Médecine, Université Henri Poincaré Nancy I, BP 184, 54500 Vandoeuvre les Nancy, France.
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18
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Dequiedt F, Van Lint J, Lecomte E, Van Duppen V, Seufferlein T, Vandenheede JR, Wattiez R, Kettmann R. Phosphorylation of histone deacetylase 7 by protein kinase D mediates T cell receptor-induced Nur77 expression and apoptosis. ACTA ACUST UNITED AC 2005; 201:793-804. [PMID: 15738054 PMCID: PMC2212830 DOI: 10.1084/jem.20042034] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The molecular basis of thymocyte negative selection, a crucial mechanism in establishing central tolerance, is not yet resolved. Histone deacetylases (HDACs) have emerged as key transcriptional regulators in several major developmental programs. Recently, we showed that the class IIa member, HDAC7, regulates negative selection by repressing expression of Nur77, an orphan nuclear receptor involved in antigen-induced apoptosis of thymocytes. Engagement of the T cell receptor (TCR) alleviates this repression through phosphorylation-dependent nuclear exclusion of HDAC7. However, the identity of the TCR-activated kinase that phosphorylates and inactivates HDAC7 was still unknown. Here, we demonstrate that TCR-induced nuclear export of HDAC7 and Nur77 expression is mediated by activation of protein kinase D (PKD). Indeed, active PKD stimulates HDAC7 nuclear export and Nur77 expression. In contrast, inhibition of PKD prevents TCR-mediated nuclear exclusion of HDAC7 and associated Nur77 activation. Furthermore, we show that HDAC7 is an interaction partner and a substrate for PKD. We identify four serine residues in the NH2 terminus of HDAC7 as targets for PKD. More importantly, a mutant of HDAC7 specifically deficient in phosphorylation by PKD, inhibits TCR-mediated apoptosis of T cell hybridomas. These findings indicate that PKD is likely to play a key role in the signaling pathways controlling negative selection.
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Affiliation(s)
- Franck Dequiedt
- Cellular and Molecular Biology Unit, Faculty of Agronomy, B-5030 Gembloux, Belgium.
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19
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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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20
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Abstract
During lymphocyte development, both B and T cells assemble antigen receptor variable region genes from germline gene segments, allowing the expression of unique receptors in each clonally derived lymphocyte. Previously, it was shown that in certain cases, progenitor and immature B cells are capable of editing their receptors to a new specificity on encounter with self-antigens. Although the existence of such a process in T cells remains controversial, recent studies suggest that mature T cells are able to similarly revise their receptors in the periphery.
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Affiliation(s)
- Raul Mostoslavsky
- Howard Hughes Medical Institute, The Children's Hospital, The Center for Blood Research, and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
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21
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Tanigaki K, Tsuji M, Yamamoto N, Han H, Tsukada J, Inoue H, Kubo M, Honjo T. Regulation of αβ/γδ T Cell Lineage Commitment and Peripheral T Cell Responses by Notch/RBP-J Signaling. Immunity 2004; 20:611-22. [PMID: 15142529 DOI: 10.1016/s1074-7613(04)00109-8] [Citation(s) in RCA: 257] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Revised: 03/03/2004] [Accepted: 03/24/2004] [Indexed: 12/19/2022]
Abstract
RBP-J is a key mediator of Notch signaling that regulates a large spectrum of cell fate determinations. To elucidate the functions of Notch signaling in T cell development, we inactivated RBP-J specifically at two stages of T cell development by crossing RBP-J floxed mice with lck-cre or CD4-cre transgenic mice. The loss of RBP-J at an earlier developmental stage resulted in enhanced generation and accelerated emigration of gammadelta T cells, whereas alphabeta T cell development was arrested at the double-negative 3 stage. The loss of RBP-J at a later stage did not affect the absolute number or the production rate of CD4 or CD8-positive mature T cells but enhanced Th1 cell response and reduced CD4(+) T cell proliferation. Our data demonstrated that Notch/RBP-J signaling regulates gammadelta T cell generation and migration, alphabeta T cell maturation, terminal differentiation of CD4(+) T cells into Th1/Th2 cells, and activation of T cells.
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Affiliation(s)
- Kenji Tanigaki
- Department of Medical Chemistry, Graduate School of Medicine, Kyoto University, Yoshida-Konoe, Sakyo-Ku, Kyoto, 606-8501, Japan
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22
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Klinger MB, Guilbault B, Kay RJ. The RhoA- and CDC42-specific exchange factor Dbs promotes expansion of immature thymocytes and deletion of double-positive and single-positive thymocytes. Eur J Immunol 2004; 34:806-816. [PMID: 14991610 DOI: 10.1002/eji.200324400] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Specific members of the Rho family of GTPases exert unique influences on thymocyte proliferation, differentiation and deletion. Dbs is a guanine nucleotide exchange factor which is expressed throughout thymocyte development and is able to activate the Rho family GTPases CDC42, RhoA and RhoG. Transgenic mice expressing an activated form of Dbs had increased numbers of double-negative thymocytes. The Dbs transgene promoted expansion of double-negative thymocytes in the absence of pre-TCR, but had no effect on pre-TCR-dependent differentiation of double-negative thymocytes into double-positive thymocytes. Transgenic double-positive thymocytes were proliferative in vivo, but were also susceptible to apoptosis in vivo and in vitro. The transgenic single-positive thymocytes had attenuated proliferative responses following TCR ligation, and were depleted rather than expanded during culture in the presence of anti-CD3. When expressing a positively selectable TCR, transgenic double-positive thymocytes were increased in number and activated, but the output of single-positive thymocytes was reduced. Transgenic double-positive thymocytes were acutely sensitive to deletion by TCR ligation in vivo. These results indicate that activation of Dbs has the potential to promote proliferation throughout thymocyte development, but also sensitizes double-positive and single-positive thymocytes to deletion.
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Affiliation(s)
- Mark B Klinger
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada
- present address: Department of Microbiology and Immunology, University of California San Francisco, 513 Parnassus Avenue, San Francisco, CA 94122, USA
| | - Benoit Guilbault
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada
| | - Robert J Kay
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada
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23
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Asmal M, Colgan J, Naef F, Yu B, Lee Y, Magnasco M, Luban J. Production of Ribosome Components in Effector CD4+ T Cells Is Accelerated by TCR Stimulation and Coordinated by ERK-MAPK. Immunity 2003; 19:535-48. [PMID: 14563318 DOI: 10.1016/s1074-7613(03)00268-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Effector CD4+ T cells rapidly activate high-level cytokine expression following TCR stimulation. Consistent with accelerated protein production in these cells, global mRNA profiles revealed that, after cytokines, the most impressive cluster of activated genes encode rRNA-maturation factors. Activation of these genes was ERK-MAPK dependent, accompanied by increased rRNA transcription and faster maturation kinetics, and much greater in effector CD4+ T cells than in naive cells. Ribosomal protein subunit (RPS) synthesis was also ERK-MAPK dependent and increased to match rRNA production, but without evident increase in RPS mRNA. Instead, stimulation promoted polysome loading of RPS mRNA via cis-acting, 5'-terminal oligopyrimidines. These results demonstrate how, in response to extracellular signals, effector CD4+ T cells coordinately increase multiple ribosomal components to accommodate burgeoning cytokine production.
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Affiliation(s)
- Mohammed Asmal
- Department of Microbiology, Columbia University College of Physicians and Surgeons, 701 West 168th Street, New York, NY 10032, USA
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24
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Henderson SC, Bamezai A. Loss of Ly-6A.2 expression on immature developing T cells in the thymus is necessary for their normal growth and generation of the Vbeta T-cell repertoire. TISSUE ANTIGENS 2003; 62:117-32. [PMID: 12889992 DOI: 10.1034/j.1399-0039.2003.00063.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Stage-specific expression of a number of cell-surface and signaling proteins is critical for normal development of T cells in the thymus. Equally important may be the loss of expression/signaling of developmentally regulated proteins for proper transitioning of developing T cells into thymic subsets. Ly-6A.2 exhibits a regulated pattern of expression on T cells maturing in the thymus, and dysregulating its expression results in arrest of developing T cells within the CD3-CD4-CD8- triple negative (TN) stage where the normal expression of Ly-6A.2 is extinguished. To further characterize the mechanisms underlying this block, we examined whether cell signaling and/or cell adhesion properties of the Ly-6A.2 molecule influenced the block in T-cell development. Analysis of bone marrow chimeras generated by injecting CFSE-labeled Ly-6A.2 transgenic bone marrow cells into irradiated syngeneic non-transgenic mice revealed normal trafficking of developing T cells from the cortex into the medulla. Production of LAT but not p56lck was diminished in CD4-CD8- DN cells from Ly-6A.2 dysregulated mice when compared with control littermates. Dysregulated expression of Ly-6A.2 did not suppress endogenous TCR-Vbeta expression. Finally, dysregulated expression of Ly-6A.2 enhanced apoptosis of an immature CD4+CD8+ (DP) subset of developing cells and altered the selected TCR-Vbeta repertoire. Taken together, these observations indicate that the termination of Ly-6A.2 expression and signaling within the CD4-CD8-CD3- subset of developing T cells is an important checkpoint during normal thymic development.
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Affiliation(s)
- S C Henderson
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
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25
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Abstract
DNA double-strand breaks (DSBs) represent dangerous chromosomal lesions that can lead to mutation, neoplastic transformation, or cell death. DSBs can occur by extrinsic insult from environmental sources or may occur intrinsically as a result of cellular metabolism or a genetic program. Mammalian cells possess potent and efficient mechanisms to repair DSBs, and thus complete normal development as well as mitigate oncogenic potential and prevent cell death. When DSB repair (DSBR) fails, chromosomal instability results and can be associated with tumor formation or progression. Studies of mice deficient in various components of the non-homologous end joining pathway of DSBR have revealed key roles in both the developmental program of B and T lymphocytes as well as in the maintenance of general genome stability. Here, we review the current thinking about DSBs and DSBR in chromosomal instability and tumorigenesis, and we highlight the implications for understanding the karyotypic features associated with human tumors.
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26
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Boursalian TE, Fink PJ. Mutation in fas ligand impairs maturation of thymocytes bearing moderate affinity T cell receptors. J Exp Med 2003; 198:349-60. [PMID: 12860933 PMCID: PMC2194074 DOI: 10.1084/jem.20030220] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Fas ligand, best known as a death-inducer, is also a costimulatory molecule required for maximal proliferation of mature antigen-specific CD4+ and CD8+ T cells. We now extend the role of Fas ligand by showing that it can also influence thymocyte development. T cell maturation in some, but not all, strains of TCR transgenic mice is severely impaired in thymocytes expressing mutant Fas ligand incapable of interacting with Fas. Mutant Fas ligand inhibits neither negative selection nor death by neglect. Instead, it appears to modulate positive selection of thymocytes expressing both class I- and class II-restricted T cell receptors of moderate affinity for their positively selecting ligands. Fas ligand is therefore an inducer of death, a costimulator of peripheral T cell activation, and an accessory molecule in positive selection.
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Affiliation(s)
- Tamar E Boursalian
- Department of Immunology, Box 357650, University of Washington, Seattle, WA 98195-7650, USA
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27
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Warren LA, Rothenberg EV. Regulatory coding of lymphoid lineage choice by hematopoietic transcription factors. Curr Opin Immunol 2003; 15:166-75. [PMID: 12633666 DOI: 10.1016/s0952-7915(03)00011-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
During lymphopoiesis, precursor cells negotiate a complex regulatory space, defined by the levels of several competing and cross-regulating transcription factors, before arriving at stable states of commitment to the B-, T- and NK-specific developmental programs. Recent perturbation experiments provide evidence that this space has three major axes, corresponding to the PU.1 versus GATA-1 balance, the intensity of Notch signaling through the CSL pathway, and the ratio of E-box transcription factors to their Id protein antagonists.
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Affiliation(s)
- Luigi A Warren
- Division of Biology, 156-29, California Institute of Technology, Pasadena, CA 91125, USA.
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28
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Abstract
Recent investigations have provided important insights into how signaling through the antigen receptors determines whether a cell survives or dies. In T cells, Grb2 and MAP kinases play essential roles in differentiating between apoptotic and survival signals. The PTEN phosphatase and Bim, a pro-apoptotic Bcl-2 family member, regulate apoptosis in both T and B cells. In B cells, antigen receptor-mediated death can be rescued by co-stimulation, in which the roles of protein kinase C and BAFF, a TNF family member, have been recently elucidated. In a recently identified mechanism of regulating inflammation, receptors such as c-mer and glycoproteins such as MFG-E8 were found to participate in the clearance of apoptotic cells.
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MESH Headings
- Animals
- Apoptosis/physiology
- Lymphocytes/cytology
- Lymphocytes/physiology
- Mice
- Mice, Transgenic
- Models, Biological
- Receptors, Antigen, B-Cell/genetics
- Receptors, Antigen, B-Cell/physiology
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/physiology
- Signal Transduction/physiology
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Affiliation(s)
- Sue J Sohn
- Department of Molecular and Cell Biology, Division of Immunology and Cancer Research Laboratory 469, Life Science Addition, University of California, Berkeley, CA 94720-3200, USA
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29
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Abstract
Shc is a prototype adapter protein that is expressed from the earliest stages of T-cell development. Shc becomes rapidly tyrosine phosphorylated after T-cell receptor (TCR) engagement. Expression of dominant negative forms of Shc in T-cell lines had also suggested a role for this adapter downstream of the TCR. However, until recently, the relative significance of Shc compared to several other adapters in T cells was unclear. Mice lacking Shc expression specifically in the T-cell lineage together with inducible expression of dominant negative Shc in transgenic mice have revealed an essential and nonredundant role for Shc in thymic T-cell development. Functional defects in a Jurkat T-cell line lacking Shc expression also suggest a role for Shc in mature T-cell functions. While the requirement of Shc in T-cell signaling is now established, precisely what signaling pathways downstream of Shc make this adapter unique are less clear. Although the Shc-mediated activation of the extracellular signal regulated kinase (Erk)/mitogen-activated protein kinase (MAPK) pathway could be one component, Shc likely signals to other pathways in T cells that are not yet discovered. A better molecular understanding of Shc function in the future could provide insights into how multiple adapters coordinate the various outcomes downstream of the TCR.
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Affiliation(s)
- Li Zhang
- Department of Microbiology and the Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA 22908, USA
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30
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Norment AM, Bogatzki LY, Klinger M, Ojala EW, Bevan MJ, Kay RJ. Transgenic expression of RasGRP1 induces the maturation of double-negative thymocytes and enhances the production of CD8 single-positive thymocytes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:1141-9. [PMID: 12538669 DOI: 10.4049/jimmunol.170.3.1141] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
RasGRP1 is a guanine nucleotide exchange factor for Ras that is required for the efficient production of both CD4 and CD8 single-positive thymocytes. We found that RasGRP1 expression is rapidly up-regulated in double-negative thymocytes following pre-TCR ligation. Transgenic overexpression of RasGRP1 compensated for deficient pre-TCR signaling in vivo, enabling recombinase-activating gene 2(-/-) double-negative thymocytes to mature to the double-positive stage. RasGRP1 transgenic mice had a 4-fold increase in CD8 single-positive thymocytes, most of which had atypically low levels of CD3. The RasGRP1 transgene lowered the threshold of TCR signaling needed to initiate proliferation of single-positive thymocytes, with this effect being particularly evident among CD8 single-positive cells. In 3-day cultures, TCR stimulation via anti-CD3 caused a 10-fold increase in the ratio of CD8 to CD4 thymocytes among RasGRP1 transgenic vs nontransgenic thymocytes. These results demonstrate that in addition to driving the double-negative to double-positive transition, increased expression of RasGRP1 selectively increases CD8 single-positive thymocyte numbers and enhances their responsiveness to TCR signaling.
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MESH Headings
- Adjuvants, Immunologic/biosynthesis
- Adjuvants, Immunologic/genetics
- Adjuvants, Immunologic/physiology
- Amino Acid Sequence
- Animals
- CD8 Antigens/biosynthesis
- CD8 Antigens/genetics
- CD8-Positive T-Lymphocytes/cytology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cell Division/genetics
- Cell Division/immunology
- Crosses, Genetic
- DNA-Binding Proteins/biosynthesis
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Guanine Nucleotide Exchange Factors
- Humans
- Lymphocyte Count
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Knockout
- Mice, Transgenic
- Molecular Sequence Data
- Nuclear Proteins
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell/physiology
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Thymus Gland/cytology
- Thymus Gland/immunology
- Thymus Gland/metabolism
- Transgenes/immunology
- Up-Regulation/genetics
- Up-Regulation/immunology
- ras Proteins/physiology
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Affiliation(s)
- Anne M Norment
- Department of Immunology, University of Washington, Seattle, WA 98195, USA
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31
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Donlin LT, Roman CA, Adlam M, Regelmann AG, Alexandropoulos K. Defective thymocyte maturation by transgenic expression of a truncated form of the T lymphocyte adapter molecule and Fyn substrate, Sin. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:6900-9. [PMID: 12471123 DOI: 10.4049/jimmunol.169.12.6900] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Adapter molecules that promote protein-protein interactions play a central role in T lymphocyte differentiation and activation. In this study, we examined the role of the T lymphocyte-expressed adapter protein and Src kinase substrate, Sin, on thymocyte function using transgenic mice expressing an activated, truncated allele of Sin (SinDeltaC). We found that SinDeltaC expression led to reduced numbers of CD4(+) and CD8(+) single-positive cells and reduced thymic cellularity due to increased thymocyte apoptosis. Because the adapter properties of Sin are mediated by tyrosine-based motifs and given that Sin is a substrate for Src tyrosine kinases, we examined the involvement of these kinases in the inhibitory effects of SinDeltaC. We found that in transgenic thymocytes, SinDeltaC was constitutively phosphorylated by the Src kinase Fyn, but not by the related kinase Lck. Using SinDeltaC and fyn(-/-) animals, we also found that the expression of Fyn was required for the inhibitory effect of SinDeltaC on thymocyte apoptosis but not for SinDeltaC-mediated inhibition of T cell maturation. The inhibitory effect of SinDeltaC on thymocyte maturation correlated with defective activation of the mitogen-activated protein kinase extracellular signal-regulated kinase. Our results suggest that the Sin mutant inhibits thymocyte differentiation through Fyn-dependent and -independent mechanisms and that endogenous Sin may be an important regulator of thymocyte development.
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Affiliation(s)
- Laura T Donlin
- Department of Pharmacology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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32
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Zhong XP, Hainey EA, Olenchock BA, Zhao H, Topham MK, Koretzky GA. Regulation of T cell receptor-induced activation of the Ras-ERK pathway by diacylglycerol kinase zeta. J Biol Chem 2002; 277:31089-98. [PMID: 12070163 DOI: 10.1074/jbc.m203818200] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
T cell development in the thymus and activation of mature T cells in the periphery depend on signals stimulated by engagement of the T cell antigen receptor (TCR). Among the second messenger cascades initiated by TCR ligation include the phosphatidylinositol pathway where the membrane phospholipid, phosphatidylinositol 4,5-bisphosphate, is hydrolyzed to inositol 1,4,5-trisphosphate and diacylglycerol (DAG). Inositol 1,4,5-trisphosphate signals a rise in intracellular free calcium, leading to translocation of nuclear factor of activated T cells into the nucleus. DAG activates RasGRP and protein kinase C theta. Because both RasGRP and protein kinase C theta are essential for thymocyte and T cell function, it is critical to understand how DAG is regulated. In this report, we demonstrate expression of DAG kinase zeta (DGKzeta, the enzyme that catalyzes the conversion of DAG to phosphatidic acid) in multiple lymphoid organs, with highest expression observed within the T cell compartment. Overexpression studies in Jurkat T cells indicate that DGKzeta interferes with TCR-induced Ras and ERK activation, AP-1 induction, and expression of the activation marker CD69. In contrast, TCR-stimulated calcium influx is not altered. Mutational analysis indicates that the kinase and DAG binding domains, but not the ankyrin repeats of DGKzeta, are required for its inhibitory effects. Collectively these studies demonstrate a potential role of DGKzeta to function as a selective negative regulator of DAG signaling on T cell activation and provide the first structure/function analysis of this enzyme in T cells.
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Affiliation(s)
- Xiao-Ping Zhong
- Signal Transduction Program, The Abramson Family Cancer Research Institute, Immunology Graduate Program, University of Pennsylvania School of Medicine, 421 Curie Boulevard, Philadelphia, PA 19104, USA
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33
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Ströbel P, Helmreich M, Menioudakis G, Lewin SR, Rüdiger T, Bauer A, Hoffacker V, Gold R, Nix W, Schalke B, Elert O, Semik M, Müller-Hermelink HK, Marx A. Paraneoplastic myasthenia gravis correlates with generation of mature naive CD4(+) T cells in thymomas. Blood 2002; 100:159-66. [PMID: 12070022 DOI: 10.1182/blood.v100.1.159] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Myasthenia gravis (MG) is the leading paraneoplastic manifestation of thymomas and is probably related to the capacity of thymomas to mature and export potentially autoreactive T cells. Why some thymomas are MG associated (MG+) and others are not (MG-) has been unclear. We addressed this question by comparing the percentages of intratumorous naive mature CD45RA+ thymocytes in 9 MG(+) and in 13 MG(-) thymomas by fluorescence-activated cell sorting analysis. Our results show that intratumorous naive CD4 T cells were present in all MG(+) thymomas and in one MG(-) thymoma with the development of MG only 2 months after surgery. By contrast, the percentage of naive CD4(+) T cells was significantly reduced in all 13 MG(-) thymomas (P <.0001). Alterations in intratumorous thymopoiesis were reflected by corresponding alterations of naive T-cell subset composition in the blood, in that only MG(-) patients had significantly decreased levels (P =.02) of naive CD4(+) T cells compared with age- and sex-matched control persons. We conclude that paraneoplastic MG is highly associated with the efficiency of thymomas to produce and export naive CD4(+) T cells. The acquisition of the CD45RA(+) phenotype on CD4(+) T cells during terminal intratumorous thymopoiesis is associated with the presence of MG in most thymoma patients.
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34
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Bousso P, Bhakta NR, Lewis RS, Robey E. Dynamics of thymocyte-stromal cell interactions visualized by two-photon microscopy. Science 2002; 296:1876-80. [PMID: 12052962 DOI: 10.1126/science.1070945] [Citation(s) in RCA: 230] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Thymocytes are selected to mature according to their ability to interact with self major histocompatibility complex (MHC)-peptide complexes displayed on the thymic stroma. Using two-photon microscopy, we performed real-time analysis of the cellular contacts made by developing thymocytes undergoing positive selection in a three-dimensional thymic organ culture. A large fraction of thymocytes within these cultures were highly motile. MHC recognition was found to increase the duration of thymocyte-stromal cell interactions and occurred as both long-lived cellular associations displaying stable cell-cell contacts and as shorter, highly dynamic contacts. Our results identify the diversity and dynamics of thymocyte interactions during positive selection.
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Affiliation(s)
- Philippe Bousso
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
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Wolfer A, Wilson A, Nemir M, MacDonald HR, Radtke F. Inactivation of Notch1 impairs VDJbeta rearrangement and allows pre-TCR-independent survival of early alpha beta Lineage Thymocytes. Immunity 2002; 16:869-79. [PMID: 12121668 DOI: 10.1016/s1074-7613(02)00330-8] [Citation(s) in RCA: 272] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Notch proteins influence cell fate decisions in many developmental systems. During lymphoid development, Notch1 signaling is essential to direct a bipotent T/B precursor toward the T cell fate, but the role of Notch1 at later stages of T cell development remains controversial. We have recently reported that tissue-specific inactivation of Notch1 in immature (CD44(-) CD25(+)) thymocytes does not affect subsequent T cell development. Here, we demonstrate that loss of Notch1 signaling at an earlier (CD44(+)CD25(+)) developmental stage results in severe perturbation of alpha beta but not gamma delta lineage development. Immature Notch1(-/-) thymocytes show impaired VDJ beta rearrangement and aberrant pre-TCR-independent survival. Collectively, our data demonstrate that Notch1 controls several nonredundant functions necessary for alpha beta lineage development.
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Affiliation(s)
- Anita Wolfer
- Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, 1066, Epalinges, Switzerland
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Ellmeier W, Sunshine MJ, Maschek R, Littman DR. Combined deletion of CD8 locus cis-regulatory elements affects initiation but not maintenance of CD8 expression. Immunity 2002; 16:623-34. [PMID: 12049715 DOI: 10.1016/s1074-7613(02)00309-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Developmental stage-, subset-, and lineage-specific CD8 enhancers have been identified recently by transgenic reporter analyses. Enhancer E8(II) (CIV-4,5) is active in both immature double-positive thymocytes (DP) and mature CD8 single-positive (SP) thymocytes and T cells, whereas E8(I) (CIII-1,2) directs expression only in mature cells. In mice lacking either E8(I) (CIII-1,2) or E8(II) (CIV-4,5), there was no effect on CD8 expression in DP thymocytes. However, deletion of both enhancers resulted in variegated expression of CD8, with appearance of CD4(+)CD8(-) SP thymocytes expressing surface markers characteristic of DP thymocytes. Consequently, fewer mature CD8(+) T cells developed from the reduced pool of DP cells. These results suggest that the initiation of CD8 expression is mediated by cis-regulatory elements that are distinct from any that may be involved in maintenance of expression.
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Wilson CB, Makar KW, Pérez-Melgosa M. Epigenetic regulation of T cell fate and function. J Infect Dis 2002; 185 Suppl 1:S37-45. [PMID: 11865438 DOI: 10.1086/338001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
During their development, T lymphocytes make sequential cell fate choices: T rather than B lymphocytes, then TCRalphabeta or TCRgammadelta, CD4 or CD8, and Th1 or Th2 lineage. These fate choices require the initiation of new programs of gene expression, and once initiated, these programs must be faithfully propagated in a heritable manner from parental cells to their progeny. With the exception of the T cell receptor, these changes in gene expression occur without a change in information encoded directly in the DNA sequence. Rather, these heritable programs of gene expression are imposed, at least in part, epigenetically through changes in chromatin structure and DNA methylation, allowing T cells to tune the threshold for expression of specific genes.
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Affiliation(s)
- Christopher B Wilson
- Department of Immunology, University of Washington School of Medicine, Seattle, WA 98195, USA.
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Zou YR, Sunshine MJ, Taniuchi I, Hatam F, Killeen N, Littman DR. Epigenetic silencing of CD4 in T cells committed to the cytotoxic lineage. Nat Genet 2001; 29:332-6. [PMID: 11687799 DOI: 10.1038/ng750] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The process of thymocyte development culminates in the maturation of helper (CD4+) and cytotoxic (CD8+) T cells from their common precursors, the CD4+CD8+ double-positive cells. A crucial step during lineage specification is the termination of expression of either the CD4 or the CD8 coreceptor. A silencer element within the first intron of the CD4 gene is sufficient for CD4 transcriptional repression in cells of the cytotoxic lineage, as well as in thymocytes at earlier stages of differentiation. Here we show that the function of the CD4 silencer is required only at distinct stages of development. Its deletion before the initiation of lineage specification resulted in CD4 derepression throughout thymocyte differentiation. By contrast, once cells committed to the cytotoxic CD8+ lineage, the CD4 locus remained silent through subsequent mitoses, even when the silencer element was excised. The epigenetic inheritance of the silenced CD4 locus was not affected by the inhibition of DNA methylation or histone deacetylation, and may thus involve other mechanisms that ensure a stable state of gene expression.
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Affiliation(s)
- Y R Zou
- Molecular Pathogenesis Program, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, New York 10016, USA.
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Lee PP, Fitzpatrick DR, Beard C, Jessup HK, Lehar S, Makar KW, Pérez-Melgosa M, Sweetser MT, Schlissel MS, Nguyen S, Cherry SR, Tsai JH, Tucker SM, Weaver WM, Kelso A, Jaenisch R, Wilson CB. A critical role for Dnmt1 and DNA methylation in T cell development, function, and survival. Immunity 2001; 15:763-74. [PMID: 11728338 DOI: 10.1016/s1074-7613(01)00227-8] [Citation(s) in RCA: 1000] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The role of DNA methylation and of the maintenance DNA methyltransferase Dnmt1 in the epigenetic regulation of developmental stage- and cell lineage-specific gene expression in vivo is uncertain. This is addressed here through the generation of mice in which Dnmt1 was inactivated by Cre/loxP-mediated deletion at sequential stages of T cell development. Deletion of Dnmt1 in early double-negative thymocytes led to impaired survival of TCRalphabeta(+) cells and the generation of atypical CD8(+)TCRgammadelta(+) cells. Deletion of Dnmt1 in double-positive thymocytes impaired activation-induced proliferation but differentially enhanced cytokine mRNA expression by naive peripheral T cells. We conclude that Dnmt1 and DNA methylation are required for the proper expression of certain genes that define fate and determine function in T cells.
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Affiliation(s)
- P P Lee
- Department of Immunology, University of Washington, Seattle, WA 98195, USA
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Schmeissner PJ, Xie H, Smilenov LB, Shu F, Marcantonio EE. Integrin functions play a key role in the differentiation of thymocytes in vivo. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:3715-24. [PMID: 11564787 DOI: 10.4049/jimmunol.167.7.3715] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
T cells express a variety of surface proteins as they develop to maturity in the thymus. In addition to the TCR-CD3 complex and the two major coreceptors, CD4 and CD8, other surface proteins expressed include receptors for cytokines, growth factors, counterreceptors, and extracellular matrix molecules. To determine the role of integrin adhesion receptors in T cell development, we have expressed a trans-dominant inhibitor of integrin function in the thymus. This inhibitor leads to a block of adhesion to fibronectin due to reduced activation of integrin receptors. This reduced adhesion leads to a partial block in differentiation from CD4-CD8- cells to CD4+CD8+ cells, after the CD25+ stage, suggesting that integrins are important during Lck-mediated differentiation. Furthermore, the overall production of CD4+ cells is reduced compared with that of CD8+ cells without changes in negative selection, suggesting that integrins may be involved in the determination of the fate of the cell as well. These results demonstrate that integrin receptor function is required for proper thymocyte development in vivo.
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Affiliation(s)
- P J Schmeissner
- Department of Pathology, Columbia University College of Physicians and Surgeons, Black Building 1422, 630 West 168th Street, New York, NY 10032, USA
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