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Kalinina AA, Khromykh LM, Kazansky DB. T Cell Receptor Chain Centricity: The Phenomenon and Potential Applications in Cancer Immunotherapy. Int J Mol Sci 2023; 24:15211. [PMID: 37894892 PMCID: PMC10607890 DOI: 10.3390/ijms242015211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 10/29/2023] Open
Abstract
T cells are crucial players in adaptive anti-cancer immunity. The gene modification of T cells with tumor antigen-specific T cell receptors (TCRs) was a milestone in personalized cancer immunotherapy. TCR is a heterodimer (either α/β or γ/δ) able to recognize a peptide antigen in a complex with self-MHC molecules. Although traditional concepts assume that an α- and β-chain contribute equally to antigen recognition, mounting data reveal that certain receptors possess chain centricity, i.e., one hemi-chain TCR dominates antigen recognition and dictates its specificity. Chain-centric TCRs are currently poorly understood in terms of their origin and the functional T cell subsets that express them. In addition, the ratio of α- and β-chain-centric TCRs, as well as the exact proportion of chain-centric TCRs in the native repertoire, is generally still unknown today. In this review, we provide a retrospective analysis of studies that evidence chain-centric TCRs, propose patterns of their generation, and discuss the potential applications of such receptors in T cell gene modification for adoptive cancer immunotherapy.
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Affiliation(s)
| | | | - Dmitry B. Kazansky
- N.N. Blokhin National Medical Research Center of Oncology of the Ministry of Health of the Russian Federation, 115478 Moscow, Russia
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2
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David NA, Lee RD, LaRue RS, Joo S, Farrar MA. Nuclear corepressors NCOR1 and NCOR2 entrain thymocyte signaling, selection, and emigration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.27.559810. [PMID: 37808728 PMCID: PMC10557688 DOI: 10.1101/2023.09.27.559810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
T cell development proceeds via discrete stages that require both gene induction and gene repression. Transcription factors direct gene repression by associating with corepressor complexes containing chromatin-remodeling enzymes; the corepressors NCOR1 and NCOR2 recruit histone deacetylases to these complexes to silence transcription of target genes. Earlier work identified the importance of NCOR1 in promoting the survival of positively-selected thymocytes. Here, we used flow cytometry and single-cell RNA sequencing to identify a broader role for NCOR1 and NCOR2 in regulating thymocyte development. Using Cd4-cre mice, we found that conditional deletion of NCOR2 had no effect on thymocyte development, whereas conditional deletion of NCOR1 had a modest effect. In contrast, Cd4-cre x Ncor1f/f x Ncor2f/f mice exhibited a significant block in thymocyte development at the DP to SP transition. Combined NCOR1/2 deletion resulted in increased signaling through the T cell receptor, ultimately resulting in elevated BIM expression and increased negative selection. The NF-κB, NUR77, and MAPK signaling pathways were also upregulated in the absence of NCOR1/2, contributing to altered CD4/CD8 lineage commitment, TCR rearrangement, and thymocyte emigration. Taken together, our data identify multiple critical roles for the combined action of NCOR1 and NCOR2 over the course of thymocyte development.
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Affiliation(s)
- Natalie A David
- Center for Immunology, Masonic Cancer Center, Department of Laboratory Medicine and Pathology, Medical School, University of Minnesota, Minneapolis, MN 55455
| | - Robin D Lee
- Center for Immunology, Masonic Cancer Center, Department of Laboratory Medicine and Pathology, Medical School, University of Minnesota, Minneapolis, MN 55455
| | - Rebecca S LaRue
- Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455
| | - Sookyong Joo
- Center for Immunology, Masonic Cancer Center, Department of Laboratory Medicine and Pathology, Medical School, University of Minnesota, Minneapolis, MN 55455
| | - Michael A Farrar
- Center for Immunology, Masonic Cancer Center, Department of Laboratory Medicine and Pathology, Medical School, University of Minnesota, Minneapolis, MN 55455
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3
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Dai R, Zhu Y, Li Z, Qin L, Liu N, Liao S, Hao B. Three-way contact analysis characterizes the higher order organization of the Tcra locus. Nucleic Acids Res 2023; 51:8987-9000. [PMID: 37534534 PMCID: PMC10516640 DOI: 10.1093/nar/gkad641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 07/07/2023] [Accepted: 07/20/2023] [Indexed: 08/04/2023] Open
Abstract
The generation of highly diverse antigen receptors in T and B lymphocytes relies on V(D)J recombination. The enhancer Eα has been implicated in regulating the accessibility of Vα and Jα genes through long-range interactions during rearrangements of the T-cell antigen receptor gene Tcra. However, direct evidence for Eα physically mediating the interaction of Vα and Jα genes is still lacking. In this study, we utilized the 3C-HTGTS assay, a chromatin interaction technique based on 3C, to analyze the higher order chromatin structure of the Tcra locus. Our analysis revealed the presence of sufficient information in the 3C-HTGTS data to detect multiway contacts. Three-way contact analysis of the Tcra locus demonstrated the co-occurrence of the proximal Jα genes, Vα genes and Eα in CD4+CD8+ double-positive thymocytes. Notably, the INT2-TEAp loop emerged as a prominent structure likely to be responsible for bringing the proximal Jα genes and the Vα genes into proximity. Moreover, the enhancer Eα utilizes this loop to establish physical proximity with the proximal Vα gene region. This study provides insights into the higher order chromatin structure of the Tcra locus, shedding light on the spatial organization of chromatin and its impact on V(D)J recombination.
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Affiliation(s)
- Ranran Dai
- Cancer Research Institute, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, China
| | - Yongchang Zhu
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou 450001, China
- Medical Genetic Institute of Henan Province, Henan Key Laboratory of Genetic Diseases and Functional Genomics, National Health Commission Key Laboratory of Birth Defects Prevention, Henan Provincial People’s Hospital, People’s Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan Province 450003, China
| | - Zhaoqiang Li
- Cancer Research Institute, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, China
| | - Litao Qin
- Medical Genetic Institute of Henan Province, Henan Key Laboratory of Genetic Diseases and Functional Genomics, National Health Commission Key Laboratory of Birth Defects Prevention, Henan Provincial People’s Hospital, People’s Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan Province 450003, China
| | - Nan Liu
- Division of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province 510515, China
| | - Shixiu Liao
- Medical Genetic Institute of Henan Province, Henan Key Laboratory of Genetic Diseases and Functional Genomics, National Health Commission Key Laboratory of Birth Defects Prevention, Henan Provincial People’s Hospital, People’s Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan Province 450003, China
| | - Bingtao Hao
- Cancer Research Institute, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, China
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou 450001, China
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4
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Dauphars DJ, Mihai A, Wang L, Zhuang Y, Krangel MS. Trav15-dv6 family Tcrd rearrangements diversify the Tcra repertoire. J Exp Med 2022; 219:212913. [PMID: 34910107 PMCID: PMC8679779 DOI: 10.1084/jem.20211581] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 11/04/2021] [Accepted: 12/02/2021] [Indexed: 11/20/2022] Open
Abstract
The Tcra repertoire is generated by multiple rounds of Vα-Jα rearrangement. However, Tcrd recombination precedes Tcra recombination within the complex Tcra-Tcrd locus. Here, by ablating Tcrd recombination, we report that Tcrd rearrangement broadens primary Vα use to diversify the Tcra repertoire in mice. We reveal that use of Trav15-dv6 family V gene segments in Tcrd recombination imparts diversity in the Tcra repertoire by instigating use of central and distal Vα segments. Moreover, disruption of the regions containing these genes and their cis-regulatory elements identifies the Trav15-dv6 family as being responsible for driving central and distal Vα recombinations beyond their roles as substrates for Tcrd recombination. Our study demonstrates an indispensable role for Tcrd recombination in general, and the Trav15-dv6 family in particular, in the generation of a combinatorially diverse Tcra repertoire.
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Affiliation(s)
| | - Ariana Mihai
- Department of Immunology, Duke University Medical Center, Durham, NC
| | - Liuyang Wang
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC
| | - Yuan Zhuang
- Department of Immunology, Duke University Medical Center, Durham, NC
| | - Michael S Krangel
- Department of Immunology, Duke University Medical Center, Durham, NC
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5
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Tfh Cells in Health and Immunity: Potential Targets for Systems Biology Approaches to Vaccination. Int J Mol Sci 2020; 21:ijms21228524. [PMID: 33198297 PMCID: PMC7696930 DOI: 10.3390/ijms21228524] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 12/16/2022] Open
Abstract
T follicular helper (Tfh) cells are a specialised subset of CD4+ T cells that play a significant role in the adaptive immune response, providing critical help to B cells within the germinal centres (GC) of secondary lymphoid organs. The B cell receptors of GC B cells undergo multiple rounds of somatic hypermutation and affinity maturation within the GC response, a process dependent on cognate interactions with Tfh cells. B cells that receive sufficient help from Tfh cells form antibody-producing long-lived plasma and memory B cells that provide the basis of decades of effective and efficient protection and are considered the gold standard in correlates of protection post-vaccination. However, the T cell response to vaccination has been understudied, and over the last 10 years, exponential improvements in the technological underpinnings of sampling techniques, experimental and analytical tools have allowed multidisciplinary characterisation of the role of T cells and the immune system as a whole. Of particular interest to the field of vaccinology are GCs and Tfh cells, representing a unique target for improving immunisation strategies. Here, we discuss recent insights into the unique journey of Tfh cells from thymus to lymph node during differentiation and their role in the production of high-quality antibody responses as well as their journey back to the periphery as a population of memory cells. Further, we explore their function in health and disease and the power of next-generation sequencing techniques to uncover their potential as modulators of vaccine-induced immunity.
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6
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Guo Y, MacIsaac KD, Chen Y, Miller RJ, Jain R, Joyce-Shaikh B, Ferguson H, Wang IM, Cristescu R, Mudgett J, Engstrom L, Piers KJ, Baltus GA, Barr K, Zhang H, Mehmet H, Hegde LG, Hu X, Carter LL, Aicher TD, Glick G, Zaller D, Hawwari A, Correll CC, Jones DC, Cua DJ. Inhibition of RORγT Skews TCRα Gene Rearrangement and Limits T Cell Repertoire Diversity. Cell Rep 2017; 17:3206-3218. [PMID: 28009290 DOI: 10.1016/j.celrep.2016.11.073] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 06/20/2016] [Accepted: 11/23/2016] [Indexed: 02/08/2023] Open
Abstract
Recent studies have elucidated the molecular mechanism of RORγT transcriptional regulation of Th17 differentiation and function. RORγT was initially identified as a transcription factor required for thymopoiesis by maintaining survival of CD4+CD8+ (DP) thymocytes. While RORγ antagonists are currently being developed to treat autoimmunity, it remains unclear how RORγT inhibition may impact thymocyte development. In this study, we show that in addition to regulating DP thymocytes survival, RORγT also controls genes that regulate thymocyte migration, proliferation, and T cell receptor (TCR)α selection. Strikingly, pharmacological inhibition of RORγ skews TCRα gene rearrangement, limits T cell repertoire diversity, and inhibits development of autoimmune encephalomyelitis. Thus, targeting RORγT not only inhibits Th17 cell development and function but also fundamentally alters thymic-emigrant recognition of self and foreign antigens. The analysis of RORγ inhibitors has allowed us to gain a broader perspective of the diverse function of RORγT and its impact on T cell biology.
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Affiliation(s)
- Yanxia Guo
- Merck Research Laboratories, 901 California Avenue, Palo Alto, CA 94304, USA
| | - Kenzie D MacIsaac
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Yi Chen
- Merck Research Laboratories, 901 California Avenue, Palo Alto, CA 94304, USA
| | - Richard J Miller
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Renu Jain
- Merck Research Laboratories, 901 California Avenue, Palo Alto, CA 94304, USA
| | | | - Heidi Ferguson
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - I-Ming Wang
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486, USA
| | - Razvan Cristescu
- Merck Research Laboratories, 901 California Avenue, Palo Alto, CA 94304, USA
| | - John Mudgett
- Merck Research Laboratories, 2000 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Laura Engstrom
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Kyle J Piers
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Gretchen A Baltus
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Kenneth Barr
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Hongjun Zhang
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Huseyin Mehmet
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | | | - Xiao Hu
- Lycera Corp, 2600 Plymouth Road, Ann Arbor, MI 48109, USA
| | - Laura L Carter
- Lycera Corp, 2600 Plymouth Road, Ann Arbor, MI 48109, USA
| | | | - Gary Glick
- Lycera Corp, 2600 Plymouth Road, Ann Arbor, MI 48109, USA
| | - Dennis Zaller
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Abbas Hawwari
- King Abdullah International Medical Research Center (KAIMRC), King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City Hospital, Ministry of National Guard Health Affairs, Mail Code 520, P.O. Box 6664, Al Hasa 31982, Kingdom of Saudi Arabia
| | - Craig C Correll
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Dallas C Jones
- Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Daniel J Cua
- Merck Research Laboratories, 901 California Avenue, Palo Alto, CA 94304, USA.
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7
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Swee LK, Tan ZW, Sanecka A, Yoshida N, Patel H, Grotenbreg G, Frickel EM, Ploegh HL. Peripheral self-reactivity regulates antigen-specific CD8 T-cell responses and cell division under physiological conditions. Open Biol 2017; 6:rsob.160293. [PMID: 27881740 PMCID: PMC5133449 DOI: 10.1098/rsob.160293] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 10/21/2016] [Indexed: 12/16/2022] Open
Abstract
T-cell identity is established by the expression of a clonotypic T-cell receptor (TCR), generated by somatic rearrangement of TCRα and β genes. The properties of the TCR determine both the degree of self-reactivity and the repertoire of antigens that can be recognized. For CD8 T cells, the relationship between TCR identity-hence reactivity to self-and effector function(s) remains to be fully understood and has rarely been explored outside of the H-2b haplotype. We measured the affinity of three structurally distinct CD8 T-cell-derived TCRs that recognize the identical H-2 Ld-restricted epitope, derived from the Rop7 protein of Toxoplasma gondii We used CD8 T cells obtained from mice generated by somatic cell nuclear transfer as the closest approximation of primary T cells with physiological TCR rearrangements and TCR expression levels. First, we demonstrate the common occurrence of secondary rearrangements in endogenously rearranged loci. Furthermore, we characterized and compared the response of Rop7-specific CD8 T-cell clones upon Toxoplasma gondii infection as well as effector function and TCR signalling upon antigenic stimulation in vitro Antigen-independent TCR cross-linking in vitro uncovered profound intrinsic differences in the effector functions between T-cell clones. Finally, by assessing the degree of self-reactivity and comparing the transcriptomes of naive Rop7 CD8 T cells, we show that lower self-reactivity correlates with lower effector capacity, whereas higher self-reactivity is associated with enhanced effector function as well as cell cycle entry under physiological conditions. Altogether, our data show that potential effector functions and basal proliferation of CD8 T cells are set by self-reactivity thresholds.
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Affiliation(s)
- Lee Kim Swee
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Zhen Wei Tan
- Department of Microbiology, National University of Singapore, Singapore.,Department of Biological Sciences, Immunology Programme, National University of Singapore, Singapore
| | - Anna Sanecka
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Nagisa Yoshida
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Harshil Patel
- Bioinformatics and Biostatistics, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Gijsbert Grotenbreg
- Department of Microbiology, National University of Singapore, Singapore.,Department of Biological Sciences, Immunology Programme, National University of Singapore, Singapore
| | - Eva-Maria Frickel
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Hidde L Ploegh
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
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8
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Carico Z, Krangel MS. Chromatin Dynamics and the Development of the TCRα and TCRδ Repertoires. Adv Immunol 2015; 128:307-61. [DOI: 10.1016/bs.ai.2015.07.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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9
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Visualization and quantification of monoallelic TCRα gene rearrangement in αβ T cells. Immunol Cell Biol 2014; 92:409-16. [PMID: 24418818 DOI: 10.1038/icb.2013.105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 12/04/2013] [Accepted: 12/04/2013] [Indexed: 11/08/2022]
Abstract
T-cell receptor α (TCRα) chain rearrangement is not constrained by allelic exclusion and thus αβ T cells frequently have rearranged both alleles of this locus. Thereby, stepwise secondary rearrangements of both TCRα loci further increase the odds for generation of an α-chain that can be positively selected in combination with a pre-existing TCRβ chain. Previous studies estimated that approximately 2-12% of murine and human αβ T cells still carry one TCRα locus in germline configuration, which must comprise a partially or even fully rearranged TCRδ locus. However, these estimates are based on a relatively small amount of individual αβ T-cell clones and αβ T-cell hybridomas analyzed to date. To address this issue more accurately, we made use of a mouse model, in which a fluorescent reporter protein is introduced into the constant region of the TCRδ locus. In this TcrdH2BeGFP system, fluorescence emanating from retained TCRδ loci enabled us to quantify monoallelically rearranged αβ T cells on a single-cell basis. Via fluorescence-activated cell sorting analysis, we determined the frequency of monoallelic TCRα rearrangements to be 1.7% in both peripheral CD4(+) and CD8(+) αβ T cells. Furthermore, we found a skewed 5' Jα gene utilization of the rearranged TCRα allele in T cells with monoallelic TCRα rearrangements. This is in line with previous descriptions of a tight interallelic positional coincidence of Jα gene segments used on both TCRα alleles. Finally, analysis of T cells from transgenic mice harboring only one functional TCRα locus implied the existence of very rare unusual translocation or episomal reintegration events of formerly excised TCRδ loci.
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10
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Kreslavsky T, Kim HJ, Koralov SB, Ghitza D, Buch T, Cantor H, Rajewsky K, von Boehmer H. Negative selection, not receptor editing, is a physiological response of autoreactive thymocytes. ACTA ACUST UNITED AC 2013; 210:1911-8. [PMID: 23980099 PMCID: PMC3782038 DOI: 10.1084/jem.20130876] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Antigen receptor editing-a process of secondary rearrangements of antigen receptor genes in autoreactive lymphocytes-is a well-established tolerance mechanism in B cells, whereas its role in T cells remains controversial. Here, we investigated this issue using a novel Tcra knock-in locus, which ensured appropriate timing of TCRα expression and allowed secondary rearrangements. Under these conditions the only response to self-antigen that could be unambiguously identified was negative selection of CD4/CD8 double positive thymocytes. No evidence could be obtained for antigen-induced TCR editing, whereas replacement of the transgenic TCRα chain by ongoing gene rearrangement occurred in some cells irrespective of the presence or absence of self-antigen.
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Affiliation(s)
- Taras Kreslavsky
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute; and 2 Program in Cellular and Molecular Medicine, Children's Hospital, and Immune Disease Institute, Harvard Medical School, Boston, MA 02115
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11
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Malhotra D, Fletcher AL, Turley SJ. Stromal and hematopoietic cells in secondary lymphoid organs: partners in immunity. Immunol Rev 2013; 251:160-76. [PMID: 23278748 DOI: 10.1111/imr.12023] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Secondary lymphoid organs (SLOs), including lymph nodes, Peyer's patches, and the spleen, have evolved to bring cells of the immune system together. In these collaborative environments, lymphocytes scan the surfaces of antigen-presenting cells for cognate antigens, while moving along stromal networks. The cell-cell interactions between stromal and hematopoietic cells in SLOs are therefore integral to the normal functioning of these tissues. Not only do stromal cells physically construct SLO architecture but they are essential for regulating hematopoietic populations within these domains. Stromal cells interact closely with lymphocytes and dendritic cells, providing scaffolds on which these cells migrate, and recruiting them into niches by secreting chemokines. Within lymph nodes, stromal cell-ensheathed conduit networks transport small antigens deep into the SLO parenchyma. More recently, stromal cells have been found to induce peripheral CD8(+) T-cell tolerance and control the extent to which newly activated T cells proliferate within lymph nodes. Thus, stromal-hematopoietic crosstalk has important consequences for regulating immune cell function within SLOs. In addition, stromal cell interactions with hematopoietic cells, other stroma, and the inflammatory milieu have profound effects on key stromal functions. Here, we examine ways in which these interactions within the lymph node environment influence the adaptive immune response.
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Affiliation(s)
- Deepali Malhotra
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA 02115, USA
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12
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Abstract
Successful allogeneic hematopoietic stem cell transplantation (HSCT) and solid organ transplantation require development of a degree of immune tolerance against allogeneic antigens. T lymphocytes play a critical role in allograft rejection, graft failure, and graft-versus-host disease (GVHD). T-cell tolerance occurs by two different mechanisms: (1) depletion of self-reactive T cells during their maturation in the thymus (central tolerance), and (2) suppression/elimination of self-reactive mature T cells in the periphery (peripheral tolerance). Induction of transplant tolerance improves transplantation outcomes. Adoptive immunotherapy with immune suppressor cells including regulatory T cells, natural killer (NK)-T cells, veto cells, and facilitating cells are promising therapies for modulation of immune tolerance. Achieving mixed chimerism with the combination of thymic irradiation and T-cell-depleting antibodies, costimulatory molecule blockade with/without inhibitory signal activation, and elimination of alloreactive T cells with varying methods including pre- or post-transplant cyclophosphamide administration appear to be effective in inducing transplant tolerance.
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Affiliation(s)
- Onder Alpdogan
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA
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13
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Thymic nurse cells provide microenvironment for secondary T cell receptor α rearrangement in cortical thymocytes. Proc Natl Acad Sci U S A 2012. [PMID: 23188800 DOI: 10.1073/pnas.1213069109] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Distinct subsets of thymic epithelial cells (TECs) support T-cell development and selection. Isolated TECs contain multicellular complexes that enclose many viable thymocytes. However, the functions of those TECs, termed thymic nurse cells (TNCs), are unclear and the idea that TNCs are present in vivo is questioned. Here, we show that TNCs represent a fraction of cortical (c)TECs that are defined by the expression of thymoproteasomes. Intravital imaging revealed TNCs in the thymic cortex in situ, whereas TNCs were detected neither during embryogenesis nor in the postnatal thymuses of various "positive-selector" T-cell receptor (TCR)-transgenic mice, indicating that TNCs are not essential for T-cell differentiation, including positive selection. Rather, cells within TNCs were enriched for long-lived CD4(+)CD8(+) thymocytes that underwent secondary TCR-Vα rearrangement. Thus, TNC complexes are formed in vivo by persistent cTEC-thymocyte interactions that then provide a microenvironment that optimizes T-cell selection through secondary TCR rearrangement.
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14
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Takase M, Iida R, Maruya M, Sakaue-Sawano A, Miyawaki A, Wakayama T, Nishigami S, Fagarasan S, Kanagawa O. Nuclear transferred embryonic stem cells for analysis of B1 B-lymphocyte development. Int Immunol 2012; 25:145-56. [PMID: 23042789 DOI: 10.1093/intimm/dxs095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The transfer of nuclei of fully differentiated cells into enucleated oocytes is a well-recognized method for the generation of embryonic stem (ES) cells. Here, we demonstrate that nuclear transferred ES (NT-ES) cells can be established with high efficiency using innate-like B lymphocytes as donor cells. We established two mouse lines carrying rearranged immunoglobulin heavy and light chains using NT-ES cells containing nuclei from peritoneal cavity B1 cells. Analysis of B1 clone lines revealed that the B1-cell generation critically depends on the interaction between antigen (possibly self-antigen) and surface immunoglobulin, while the B1-cell maintenance requires the peritoneal environment. The B1-cell expansion takes place in spleen, and is held in check by competitor B2 cells. The results indicate that the NT-ES method could replace the transgenic or knock-in mouse approaches currently used to study the biology of cells that undergo somatic rearrangements of their antigen receptor genes.
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Affiliation(s)
- Mitsuyo Takase
- Laboratory for Autoimmune Regulation, RIKEN, Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Yokohama, Kanagawa 230-0045, Japan
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15
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Abstract
Somatic recombination of TCR genes in immature thymocytes results in some cells with useful TCR specificities, but also many with useless or potentially self-reactive specificities. Thus thymic selection mechanisms operate to shape the T-cell repertoire. Thymocytes that have a TCR with low affinity for self-peptide-MHC complexes are positively selected to further differentiate and function in adaptive immunity, whereas useless ones die by neglect. Clonal deletion and clonal diversion (Treg differentiation) are the major processes in the thymus that eliminate or control self-reactive T cells. Although these processes are thought to be efficient, they fail to control self-reactivity in all circumstances. Thus, peripheral tolerance processes exist wherein self-reactive T cells become functionally unresponsive (anergy) or are deleted after encountering self-antigens outside of the thymus. Recent advances in mechanistic studies of central and peripheral T-cell tolerance are promoting the development of therapeutic strategies to treat autoimmune disease and cancer and improve transplantation outcome.
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Affiliation(s)
- Yan Xing
- Center for Immunology, Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, 55455, USA
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Jones ME, Zhuang Y. Stage-specific functions of E-proteins at the β-selection and T-cell receptor checkpoints during thymocyte development. Immunol Res 2011; 49:202-15. [PMID: 21128008 DOI: 10.1007/s12026-010-8182-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The E-protein transcription factors E2A and HEB function in a lineage- and stage-specific manner to orchestrate many critical events throughout lymphocyte development. The function of E-proteins in both B- and T-lymphocyte development has been extensively studied through the use of single-gene knockout animals. Unlike B cells, which rely primarily on E2A alone, T cells are regulated by the combinatorial expression of both E2A and HEB. Therefore, many of the roles of E-proteins during T-cell development may be masked in single-gene knockout studies due to the compensatory function of E2A and HEB. More recently, our laboratory has established double-conditional knockout models to eliminate both E2A and HEB in a stage-specific manner throughout T-cell development. These models, in combination with other complimentary genetic approaches, have identified new E-protein functions at each of the two major T-cell developmental checkpoints. Here, we will discuss how E-proteins function to regulate the expression of T-cell receptor components and cell cycle at the β-selection checkpoint, and how they control positive selection, survival, and lineage-specific gene expression at the subsequent T-cell receptor checkpoint.
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Affiliation(s)
- Mary Elizabeth Jones
- Department of Immunology, Duke University Medical Center, Box 3010, Durham, NC 27710, USA.
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17
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TCR affinity for self-ligands influences the development and function of encephalitogenic T cells. PLoS One 2011; 6:e17702. [PMID: 21437282 PMCID: PMC3060088 DOI: 10.1371/journal.pone.0017702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Accepted: 02/08/2011] [Indexed: 11/25/2022] Open
Abstract
The specificity and affinity of self-reactive T cells is likely to impact the development of autoimmune-disease causing T cells in the thymus as well as their function in the periphery. We identified a naturally occurring, low affinity variant of an MBP Ac1-11/I-Au specific TCR that is known to induce EAE. Thymocytes in mice carrying the transgenes for this low affinity TCR were poorly positively selected, as compared to their high affinity TCR expressing counterparts. Nonetheless, CD4 T cells bearing the low affinity TCR accumulated in the periphery of the mice. Unlike mice expressing the high affinity TCR, these mice very rarely developed disease. However, if endogenous TCR expression was eliminated by breeding to RAG1 deficient mice, 100% of the mice carrying either the high or the low affinity versions of the TCR developed EAE. Intriguingly, while the incidence of EAE increased, the age of onset of disease in both mice was identical. These data suggest disease onset occurs during a short window of mouse development.
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Abstract
The thymus serves as the central organ of immunologic self-nonself discrimination. Thymocytes undergo both positive and negative selection, resulting in T cells with a broad range of reactivity to foreign antigens but with a lack of reactivity to self-antigens. The thymus is also the source of a subset of regulatory T cells that inhibit autoreactivity of T-cell clones that may escape negative selection. As a result of these functions, the thymus has been shown to be essential for the induction of tolerance in many rodent and large animal models. Proper donor antigen presentation in the thymus after bone marrow, dendritic cell, or solid organ transplantation has been shown to induce tolerance to allografts. The molecular mechanisms of positive and negative selection and regulatory T-cell development must be understood if a tolerance-inducing therapeutic intervention is to be designed effectively. In this brief and selective review, we present some of the known information on T-cell development and on the role of the thymus in experimental models of transplant tolerance. We also cite some clinical attempts to induce tolerance to allografts using pharmacologic or biologic interventions.
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Numerical modelling of the V-J combinations of the T cell receptor TRA/TRD locus. PLoS Comput Biol 2010; 6:e1000682. [PMID: 20174554 PMCID: PMC2824756 DOI: 10.1371/journal.pcbi.1000682] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 01/21/2010] [Indexed: 01/07/2023] Open
Abstract
T-Cell antigen Receptor (TR) repertoire is generated through rearrangements of V and J genes encoding α and β chains. The quantification and frequency for every V-J combination during ontogeny and development of the immune system remain to be precisely established. We have addressed this issue by building a model able to account for Vα-Jα gene rearrangements during thymus development of mice. So we developed a numerical model on the whole TRA/TRD locus, based on experimental data, to estimate how Vα and Jα genes become accessible to rearrangements. The progressive opening of the locus to V-J gene recombinations is modeled through windows of accessibility of different sizes and with different speeds of progression. Furthermore, the possibility of successive secondary V-J rearrangements was included in the modelling. The model points out some unbalanced V-J associations resulting from a preferential access to gene rearrangements and from a non-uniform partition of the accessibility of the J genes, depending on their location in the locus. The model shows that 3 to 4 successive rearrangements are sufficient to explain the use of all the V and J genes of the locus. Finally, the model provides information on both the kinetics of rearrangements and frequencies of each V-J associations. The model accounts for the essential features of the observed rearrangements on the TRA/TRD locus and may provide a reference for the repertoire of the V-J combinatorial diversity. Lymphocytes of the immune system ensure the body defense by the expression of receptors which are specific of targets, termed antigens. Each lymphocyte, deriving from the same original clone, expresses the same unique receptor. To achieve the production of receptors covering the wide variety of antigens, lymphocytes use a specialized genetic mechanism consisting of gene rearrangements. For instance, the genes encoding the receptor of the alpha chain of the T lymphocyte receptor (TRA) spread over a 1500 Kb genetic region which includes around 100 V genes, 60 J genes, and a single C gene. To constitute a functional alpha chain, one of the V and one of the J genes rearrange together to form a single exon. The precise definition of these V-J combinations is essential to understand the repertoire of TRA. We have developed a numerical model simulating all of the V-J combinations of TRA, fitting the available experimental observations obtained from the analysis of TRA in T lymphocytes of the thymus and the blood. Our model gives new insights on the rules controlling the use of V and J genes in providing a dynamic estimation of the total V-J combinations.
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Yuan J, Crittenden RB, Bender TP. c-Myb promotes the survival of CD4+CD8+ double-positive thymocytes through upregulation of Bcl-xL. THE JOURNAL OF IMMUNOLOGY 2010; 184:2793-804. [PMID: 20142358 DOI: 10.4049/jimmunol.0902846] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mechanisms that regulate the lifespan of CD4(+)CD8(+) double-positive (DP) thymocytes help shape the peripheral T cell repertoire. However, the molecular mechanisms controlling DP thymocyte survival remain poorly understood. The Myb proto-oncogene encodes a transcription factor required during multiple stages of T cell development. We demonstrate that Myb mRNA expression is upregulated as thymocytes differentiate from the double-negative into the metabolically quiescent, small, preselection DP stage during T cell development. Using a conditional deletion mouse model, we demonstrate that Myb-deficient DP thymocytes undergo premature apoptosis, resulting in a limited Tcralpha repertoire biased toward 5' Jalpha segment usage. Premature apoptosis occurs specifically in the small preselection DP compartment in an alphabetaTCR-independent manner and is a consequence of decreased Bcl-xL expression. Forced Bcl-xL expression is able to rescue survival, and reintroduction of c-Myb restores both Bcl-xL expression and the small preselection DP compartment. We further demonstrate that c-Myb promotes transcription at the Bcl2l1 locus via a genetic pathway that is independent of the expression of T cell-specific factor-1 or RORgammat, two transcription factors that induce Bcl-xL expression in T cell development. Thus, Bcl-xL is a novel mediator of c-Myb activity during normal T cell development.
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Affiliation(s)
- Joan Yuan
- Department of Microbiology, Beirne B Carter Center for Immunology Research, University of Virginia Health System, Charlottesville, VA 22908, USA
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22
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Abstract
Cell-based cancer vaccines are a highly attractive alternative to standard cancer therapies. They theoretically have the capability of inciting a multitargeted therapeutic response that functions by reshaping the host-tumor interaction, tipping the balance in favor of tumor rejection. Due to the polyclonal immune response induced, they are less likely to result in therapeutic escape than most cancer treatments in use today. Their immune-based mechanism of action offers a unique approach to management that should not be limited by traditional modes of drug resistance. Their favorable side-effect profile further identifies them as a potential treatment modality of choice. Despite these positive features, a number of hurdles must be overcome in order for cancer vaccines to take their place in the clinic as part of standard cancer therapy. Vaccine protocols must be optimized both to induce a high-quality antitumor T-cell response and to abrogate established mechanisms of immune tolerance that actively function to shut antitumor T cells down. By applying basic knowledge of the molecular features of T-cell biology and immune tolerance to the design of trials that combine tumor vaccines with targeted immunomodulatory drugs, potent strategies for inducing effective antitumor immunity can be developed. The first of these combinatorial trials have already been reported and offer a tantalizing glimpse of the future of cancer immunotherapy.
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Affiliation(s)
- Leisha A Emens
- Department of Oncology, Johns Hopkins University and the Sidney Kimmel Comprehensive Cancer Center, Baltimore, Maryland 21231-1000, USA.
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23
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Krangel MS. Mechanics of T cell receptor gene rearrangement. Curr Opin Immunol 2009; 21:133-9. [PMID: 19362456 DOI: 10.1016/j.coi.2009.03.009] [Citation(s) in RCA: 168] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Accepted: 03/13/2009] [Indexed: 11/20/2022]
Abstract
The four T cell receptor genes (Tcra, Tcrb, Tcrg, Tcrd) are assembled by V(D)J recombination according to distinct programs during intrathymic T cell development. These programs depend on genetic factors, including gene segment order and recombination signal sequences. They also depend on epigenetic factors. Regulated changes in chromatin structure, directed by enhancers and promoter, can modify the availability of recombination signal sequences to the RAG recombinase. Regulated changes in locus conformation may control the synapsis of distant recombination signal sequences, and regulated changes in subnuclear positioning may influence locus recombination events by unknown mechanisms. Together these influences may explain the ordered activation and inactivation of T cell receptor locus recombination events and the phenomenon of Tcrb allelic exclusion.
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Affiliation(s)
- Michael S Krangel
- Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA.
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Regulation of V(D)J recombination by E-protein transcription factors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 650:148-56. [PMID: 19731808 DOI: 10.1007/978-1-4419-0296-2_12] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Extensive study of the E-proteins E2A and HEB duringlymphocyte development has revealed various functions for these bHLH transcription factors in regulating V(D)J recombination in both B- and T-cells. The study of E-proteins in mammals began with the identification of E2A by its ability to bind immunoglobulin heavy and light chain enhancers. Subsequent analysis has identified numerous roles for E2A and HEB at the immunoglobulin and T-cell receptor loci. E-protein targets also include the rag genes and other factors critical for recombination and for regulation of the developmental windows when cells undergo recombination. E-proteins appear to be master regulators that coordinate antigen receptor gene rearrangement and expression. This chapter focuses on how E-proteins regulate V(D)J recombination by activating transcription, initiating rearrangement and driving differentiation during B- and T-cell development.
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25
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Abarrategui I, Krangel MS. Germline transcription: a key regulator of accessibility and recombination. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 650:93-102. [PMID: 19731804 DOI: 10.1007/978-1-4419-0296-2_8] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The developmental control of V(D)J recombination is imposed at the level of chromatin accessibility of recombination signal sequences (RSSs) to the recombinase machinery. Cis-acting transcriptional regulatory elements such as promoters and enhancers play a central role in the control of accessibility in vivo. However, the molecular mechanisms by which these elements influence accessibility are still under investigation. Although accessibility for V(D)J recombination is usually accompanied by germline transcription at antigen receptor loci, the functional significance of this transcription in directing RSS accessibility has been elusive. In this chapter, we review past studies outlining the complex relationship between V(D)J recombination and transcription as well as our current understanding on how chromatin structure is regulated during gene expression. We then summarize recent work that directly addresses the functional role of transcription in V(D)J recombination.
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Affiliation(s)
- Iratxe Abarrategui
- Centre for Epigenetics, Biotech Research and Innovation Centre, Copenhagen, Denmark
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26
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McCaughtry TM, Hogquist KA. Central tolerance: what have we learned from mice? Semin Immunopathol 2008; 30:399-409. [PMID: 19015857 DOI: 10.1007/s00281-008-0137-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Accepted: 10/01/2008] [Indexed: 10/21/2022]
Abstract
Producing a healthy immune system capable of defending against pathogens, while avoiding autoimmunity, is dependent on thymic selection. Positive selection yields functional T cells that have the potential to recognize both self and foreign antigens. Therefore, negative selection exists to manage potentially self-reactive cells. Negative selection results from the induction of anergy, receptor editing, clonal diversion (agonist selection), and/or clonal deletion (apoptosis) in self-reactive clones. Clonal deletion has been inherently difficult to study because the cells of interest are undergoing apoptosis and being eliminated quickly. Furthermore, analysis of clonal deletion in humans has proved even more difficult due to availability of samples and lack of reagents. Mouse models have thus been instrumental in achieving our current understanding of central tolerance, and the evolution of elegant model systems has led to an explosion of new data to be assimilated. This review will focus on recent advances in the field of clonal deletion with respect to three aspects: the development of physiological model systems, signaling pathways that lead to apoptosis, and antigen presenting cell types involved in the induction of clonal deletion.
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Affiliation(s)
- Tom M McCaughtry
- Center for Immunology, Laboratory Medicine & Pathology, University of Minnesota, Mayo Mail Code 334, 420 Delaware Street SE, Minneapolis, MN, 55454, USA
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27
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Gill BC, Jeon CH, Sung HN, Kim HL, Jin DW, Park JH. 2,3,7,8-Tetrachlorodibenzo-p-dioxin modulates the expression of cKrox and Runx3, transcription regulatory factors controlling the lineage commitment of CD4+CD8+ into CD4 and CD8 thymocytes, respectively. Toxicol Lett 2008; 180:189-95. [DOI: 10.1016/j.toxlet.2008.06.856] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 05/21/2008] [Accepted: 06/09/2008] [Indexed: 11/17/2022]
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28
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Mori Y, Kato T, Kodaka T, Kanagawa EM, Hori S, Kanagawa O. Protection of IFN-γ signaling-deficient NOD mice from diabetes by cyclophosphamide. Int Immunol 2008; 20:1231-7. [DOI: 10.1093/intimm/dxn080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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29
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Non-redundant function of the MEK5-ERK5 pathway in thymocyte apoptosis. EMBO J 2008; 27:1896-906. [PMID: 18548009 DOI: 10.1038/emboj.2008.114] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Accepted: 05/23/2008] [Indexed: 11/09/2022] Open
Abstract
The mitogen-activated protein kinases (MAPKs) ERK1/2, p38, and JNK are thought to determine survival-versus-death fate in developing thymocytes. However, this view was challenged by studies using 'MEK1-ERK1/2-specific' pharmacological inhibitors, which block both positive and negative selection. Recently, these inhibitors were also shown to affect MEK5, an upstream activator of ERK5, another class of MAPK with homology to ERK1/2. To define the contribution of the MEK5-ERK5 pathway in T-cell development, we retrovirally expressed dominant-negative or constitutively activated form of MEK5 to inhibit or activate the MEK5-ERK5 pathway. We demonstrate that MEK5 regulates apoptosis of developing thymocytes but has no function in positive selection. ERK5 activity correlates with the levels of Nur77 family members but not that of Bim, two effector pathways of thymocyte apoptosis. These results illustrate the critical involvement of the MEK5-ERK5 pathway in thymocyte development distinct from that of ERK1/2 and highlight the importance of the MAPK network in mediating differential effects pertaining to T-cell differentiation and apoptosis.
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Jones ME, Zhuang Y. Acquisition of a functional T cell receptor during T lymphocyte development is enforced by HEB and E2A transcription factors. Immunity 2008; 27:860-70. [PMID: 18093538 DOI: 10.1016/j.immuni.2007.10.014] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Revised: 09/20/2007] [Accepted: 10/31/2007] [Indexed: 11/30/2022]
Abstract
The T cell receptor (TCR) is required for positive selection and the subsequent transition from the CD4(+)CD8(+) double-positive (DP) to the CD4(+) or CD8(+) single-positive (SP) stage of alphabeta T cell development. The molecular mechanism that maintains DP fate prior to the acquisition of a functional TCR is not clear. We have shown here that the structurally and functionally related transcription factors HEB and E2A work together to maintain DP fate and to control the DP to SP transition. Simultaneous deletion of HEB and E2A in DP thymocytes was sufficient for DP to SP transition independent of TCR. Loss of HEB and E2A allowed DP cells to bypass the requirement for TCR-mediated positive selection, downregulate DP-associated genes, and upregulate SP-specific genes. These results identify HEB and E2A as the gatekeepers that maintain cells at the DP stage of development until a functional alphabetaTCR is produced.
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Affiliation(s)
- Mary Elizabeth Jones
- Department of Immunology, Duke University Medical Center, Box 3010, Durham, NC 27710, USA
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31
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Takase M, Kanagawa EM, Kanagawa O. Age-dependent TCR revision mediated by interaction between alphabeta TCR and self-antigens. THE JOURNAL OF IMMUNOLOGY 2007; 179:2163-9. [PMID: 17675475 DOI: 10.4049/jimmunol.179.4.2163] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Interactions between TCR and self-peptide/MHC complex play an important role in homeostasis and Ag reactivity of mature peripheral T cells. In this report, we demonstrate that the interactions between mature peripheral T cells and endogenous Ags have a negative impact on the maintenance of foreign Ag-specific T cells in an age-dependent manner. This is mediated by RAG-dependent secondary rearrangement of the TCR alpha-chain (receptor revision). The TCR revision in mature T cells is readily observed in mouse expressing transgenic TCR alpha-chain inserted into the physiological locus (knockin mouse) but not in conventional transgenic mouse with an identical TCR alpha-chain. Thus, our results suggest that under physiological conditions in which all TCR alpha-chains are susceptible to deletion by secondary rearrangement, TCR revision in mature peripheral T cells is an ongoing process in adult animals and contributes to age-dependent changes in T cell function and repertoire.
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Affiliation(s)
- Mitsuyo Takase
- RIKEN Center for Allergy and Immunology, RIKEN Yokohama Institute, Yokohama, Japan
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32
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Abarrategui I, Krangel MS. Noncoding transcription controls downstream promoters to regulate T-cell receptor alpha recombination. EMBO J 2007; 26:4380-90. [PMID: 17882258 PMCID: PMC2034674 DOI: 10.1038/sj.emboj.7601866] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Accepted: 08/30/2007] [Indexed: 01/08/2023] Open
Abstract
The T early alpha (TEA) promoter in the murine Tcra locus generates noncoding transcripts that extend across the 65 kb Jalpha array. Here, we have analyzed the significance of TEA transcription for Tcra locus regulation through the targeted introduction of a transcription terminator downstream of the TEA promoter. We demonstrate that noncoding transcription driven by this single promoter can instruct both positively and negatively the activity of downstream Jalpha promoters, and can similarly instruct alterations in Jalpha chromatin structure and Jalpha recombination. TEA transcription activates promoters associated with relatively proximal Jalpha segments and stimulates histone acetylation, histone methylation and chromatin accessibility in this region. In contrast, at more distal locations, TEA transcription inhibits promoter activity through transcriptional interference and suppresses chromatin accessibility. In combination, these effects target initial Valpha-to-Jalpha recombination to TEA-proximal Jalpha segments and promote the ordered usage of the Jalpha array. The ability of TEA transcription to coordinate the activity of multiple downstream promoters maximizes the biological potential of the Jalpha array and diversifies the Tcra repertoire.
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MESH Headings
- Acetylation
- Animals
- Base Sequence
- Chromatin/chemistry
- Histones/chemistry
- Mice
- Mice, Transgenic
- Models, Genetic
- Molecular Sequence Data
- Promoter Regions, Genetic
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/physiology
- Recombination, Genetic
- T-Lymphocytes/metabolism
- Transcription, Genetic
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Affiliation(s)
- Iratxe Abarrategui
- Department of Immunology, Duke University Medical Center, Durham, NC, USA
| | - Michael S Krangel
- Department of Immunology, Duke University Medical Center, Durham, NC, USA
- Department of Immunology, Duke University Medical Center, Duke University, 318 Jones Bldg, Box 3010, Durham, NC 27710, USA. Tel.: +1 919 684 4985; Fax: +1 919 684 8982; E-mail:
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Lantelme E, Orlando L, Porcedda P, Turinetto V, De Marchi M, Amoroso A, Mantovani S, Giachino C. An in vitro model of T cell receptor revision in mature human CD8+ T cells. Mol Immunol 2007; 45:328-37. [PMID: 17659780 DOI: 10.1016/j.molimm.2007.06.153] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Revised: 06/07/2007] [Accepted: 06/17/2007] [Indexed: 11/20/2022]
Abstract
V(D)J recombination is a mechanism peculiar to the somatic rearrangement of antigen receptor genes. It requires both expression of the RAG-1 and RAG-2 recombinases and accessibility of the substrate to its recombinase and post-cleavage/DNA repair stage. TCR revision is a genetic correction mechanism that changes T cell specificity by re-activating V(D)J recombination in peripheral T cells. This process is now well described in both normal or pathological murine and human settings. Many of its features, such as the question of whether it occurs in truly mature T cells, remain to be elucidated. Its occurrence in human CD8+ T cells is also an open question. We have therefore established an in vitro model of TCR revision in mature human CD8+ T cells to determine whether down-regulation of the TCR/CD3 complex from the cell surface in the presence of IL7 as a factor favouring chromatin remodelling initiates a TCR revision pathway. Only mature CD8+ T cells carrying already-formed antigen receptors were used. CD8+ T cells treated with anti-CD3 and IL7 showed rearrangement intermediates and expressed new Vbeta-chains on their surface. Investigation of the molecular pathway thus induced disclosed up-regulation of the RAG-2 transcript, but absence of the 'canonical' RAG-1 mRNA. A surprising finding was the demonstration of alternative splice forms of this mRNA, already expressed in untreated CD8+ T cells, encoding for the full-length RAG-1 protein, which was increased three-fold in the treated cells. All the V(D)J requirements were thus fulfilled when mature human CD8+ T cells were stimulated with anti-CD3 and IL7. Induction of TCR revision in vitro in mature T cells is an easily controllable system that could be employed in further studies to elucidate the molecular pathways involved in secondary V(D)J rearrangements in peripheral cells.
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Affiliation(s)
- Erica Lantelme
- Department of Clinical and Biological Sciences, University of Turin, Regione Gonzole 10, 10043 Orbassano, Italy.
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34
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Huang CY, Sharma GG, Walker LM, Bassing CH, Pandita TK, Sleckman BP. Defects in coding joint formation in vivo in developing ATM-deficient B and T lymphocytes. ACTA ACUST UNITED AC 2007; 204:1371-81. [PMID: 17502661 PMCID: PMC2118620 DOI: 10.1084/jem.20061460] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ataxia-telangiectasia mutated (ATM)–deficient lymphocytes exhibit defects in coding joint formation during V(D)J recombination in vitro. Similar defects in vivo should affect both T and B cell development, yet the lymphoid phenotypes of ATM deficiency are more pronounced in the T cell compartment. In this regard, ATM-deficient mice exhibit a preferential T lymphopenia and have an increased incidence of nontransformed and transformed T cells with T cell receptor α/δ locus translocations. We demonstrate that there is an increase in the accumulation of unrepaired coding ends during different steps of antigen receptor gene assembly at both the immunoglobulin and T cell receptor loci in developing ATM-deficient B and T lymphocytes. Furthermore, we show that the frequency of ATM-deficient αβ T cells with translocations involving the T cell receptor α/δ locus is directly related to the number of T cell receptor α rearrangements that these cells can make during development. Collectively, these findings demonstrate that ATM deficiency leads to broad defects in coding joint formation in developing B and T lymphocytes in vivo, and they provide a potential molecular explanation as to why the developmental impact of these defects could be more pronounced in the T cell compartment.
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Affiliation(s)
- Ching-Yu Huang
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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35
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Hawwari A, Krangel MS. Role for rearranged variable gene segments in directing secondary T cell receptor alpha recombination. Proc Natl Acad Sci U S A 2007; 104:903-7. [PMID: 17210914 PMCID: PMC1783412 DOI: 10.1073/pnas.0608248104] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Indexed: 11/18/2022] Open
Abstract
During the recombination of variable (V) and joining (J) gene segments at the T cell receptor alpha locus, a ValphaJalpha joint resulting from primary rearrangement can be replaced by subsequent rounds of secondary rearrangement that use progressively more 5' Valpha segments and progressively more 3' Jalpha segments. To understand the mechanisms that target secondary T cell receptor alpha recombination, we studied the behavior of a T cell receptor alpha allele (HYalpha) engineered to mimic a natural primary rearrangement of TRAV17 to Jalpha57. The introduced ValphaJalpha segment was shown to provide chromatin accessibility to Jalpha segments situated within several kilobases downstream and to suppress germ-line Jalpha promoter activity and accessibility at greater distances. As a consequence, the ValphaJalpha segment directed secondary recombination events to a subset of Jalpha segments immediately downstream from the primary rearrangement. The data provide the mechanistic basis for a model of primary and secondary T cell receptor alpha recombination in which recombination events progress in multiple small steps down the Jalpha array.
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Affiliation(s)
- Abbas Hawwari
- Department of Immunology, Duke University Medical Center, Durham, NC 27710
| | - Michael S. Krangel
- Department of Immunology, Duke University Medical Center, Durham, NC 27710
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Abstract
The specificities of lymphocytes for antigen are generated by a quasi-random process of gene rearrangement that often results in non-functional or autoreactive antigen receptors. Regulation of lymphocyte specificities involves not only the elimination of cells that display 'unsuitable' receptors for antigen but also the active genetic correction of these receptors by secondary recombination of the DNA. As I discuss here, an important mechanism for the genetic correction of antigen receptors is ongoing recombination, which leads to receptor editing. Receptor editing is probably an adaptation that is necessitated by the high probability of receptor autoreactivity. In both B cells and T cells, the genes that encode the two chains of the antigen receptor seem to be specialized to promote, on the one hand, the generation of diverse specificities and, on the other hand, the regulation of these specificities through efficient editing.
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Affiliation(s)
- David Nemazee
- Department of Immunology, The Scripps Research Institute, Mail Drop IMM-29, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
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37
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Wagner DH. Re-shaping the T cell repertoire: TCR editing and TCR revision for good and for bad. Clin Immunol 2006; 123:1-6. [PMID: 16990051 DOI: 10.1016/j.clim.2006.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2006] [Revised: 08/03/2006] [Accepted: 08/04/2006] [Indexed: 11/22/2022]
Abstract
Protection against the universe of pathogens requires a functional, diverse T cell repertoire. However, the price that is paid for an evolved, effective immune system includes the potential danger of generating autoaggressive T cells. Autoimmune diseases result from inherent breach of tolerance to self-antigens leading to disruption of the regulatory to autoaggressive T cell homeostatic balance. The immune system has evolved mechanisms to control those processes. For T cells, positive and negative selection in the thymus assures that only fully functional, non-self-reactive T cells will populate the periphery. Failure of this central tolerance would result in autoaggressive T cells escaping into the periphery. However, other means of escaping negative selection can occur in the periphery, i.e., TCR revision, or the altering of TCR expression after thymic egress. Here the potential benefits, i.e., expansion and re-shaping of the T cell repertoire as potentiated by TCR editing and revision are considered. Furthermore, the potential to develop autoaggressive TCR and thus enhance autoimmunity is considered.
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Affiliation(s)
- David H Wagner
- Webb-Waring Institute, Department of Medicine, University of Colorado Denver and Health Sciences Center, 4200 East 9th Ave, Denver, CO, USA.
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38
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Yélamos J, Monreal Y, Saenz L, Aguado E, Schreiber V, Mota R, Fuente T, Minguela A, Parrilla P, de Murcia G, Almarza E, Aparicio P, Ménissier-de Murcia J. PARP-2 deficiency affects the survival of CD4+CD8+ double-positive thymocytes. EMBO J 2006; 25:4350-60. [PMID: 16946705 PMCID: PMC1570435 DOI: 10.1038/sj.emboj.7601301] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Accepted: 08/01/2006] [Indexed: 12/18/2022] Open
Abstract
Poly-(ADP-ribose) polymerase-2 (PARP-2) belongs to a large family of enzymes that synthesize and transfer ADP-ribose polymers to acceptor proteins, modifying their functional properties. PARP-2-deficient (Parp-2-/-) cells, similar to Parp-1-/- cells, are sensitive to both ionizing radiation and alkylating agents. Here we show that inactivation of mouse Parp-2, but not Parp-1, produced a two-fold reduction in CD4+CD8+ double-positive (DP) thymocytes associated with decreased DP cell survival. Microarray analyses revealed increased expression of the proapoptotic Bcl-2 family member Noxa in Parp-2-/- DP thymocytes compared to littermate controls. In addition, DP thymocytes from Parp-2-/- have a reduced expression of T-cell receptor (TCR)alpha and a skewed repertoire of TCRalpha toward the 5' Jalpha segments. Our results show that in the absence of PARP-2, the survival of DP thymocytes undergoing TCRalpha recombination is compromised despite normal amounts of Bcl-xL. These data suggest a novel role for PARP-2 as an important mediator of T-cell survival during thymopoiesis by preventing the activation of DNA damage-dependent apoptotic response during the multiple rounds of TCRalpha rearrangements preceding a positively selected TCR.
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Affiliation(s)
- José Yélamos
- Department of Biochemistry, Molecular Biology and Immunology, School of Medicine, University of Murcia, Murcia, Spain
- These authors contributed equally to this work
- Departamento de Bioquímica, Biología Molecular e Inmunología, Facultad de Medicina, Campus de Espinardo, Apartado de Correos 4021, Universidad de Murcia, 30100-Murcia, Spain. Tel.: +34 968 369090; Fax: +34 968 369678; E-mail:
| | - Yolanda Monreal
- Transplant Unit, University Hospital ‘Virgen de la Arrixaca', Murcia, Spain
- These authors contributed equally to this work
| | - Luis Saenz
- Transplant Unit, University Hospital ‘Virgen de la Arrixaca', Murcia, Spain
| | - Enrique Aguado
- Department of Biochemistry, Molecular Biology and Immunology, School of Medicine, University of Murcia, Murcia, Spain
| | - Valérie Schreiber
- UPR 9003 du Centre National de la Recherche Scientifique, Strasbourg, France
| | - Rubén Mota
- Transplant Unit, University Hospital ‘Virgen de la Arrixaca', Murcia, Spain
| | - Teodomiro Fuente
- Transplant Unit, University Hospital ‘Virgen de la Arrixaca', Murcia, Spain
| | - Alfredo Minguela
- Immunology Unit, University Hospital ‘Virgen de la Arrixaca', Murcia, Spain
| | - Pascual Parrilla
- Transplant Unit, University Hospital ‘Virgen de la Arrixaca', Murcia, Spain
| | - Gilbert de Murcia
- UPR 9003 du Centre National de la Recherche Scientifique, Strasbourg, France
| | | | - Pedro Aparicio
- Department of Biochemistry, Molecular Biology and Immunology, School of Medicine, University of Murcia, Murcia, Spain
| | - Josiane Ménissier-de Murcia
- UPR 9003 du Centre National de la Recherche Scientifique, Strasbourg, France
- UPR 9003 du Centre National de la Recherche Scientifique, Ecole Supérieure de Biotechnologie de Strasbourg, Boulevard Sébastien Brant, BP10413, 67412 Illkirch, Strasbourg, France. Tel.: +33 390 244704; Fax: +33 390 244686; E-mail:
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39
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Abarrategui I, Krangel MS. Regulation of T cell receptor-alpha gene recombination by transcription. Nat Immunol 2006; 7:1109-15. [PMID: 16936730 DOI: 10.1038/ni1379] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2006] [Accepted: 07/21/2006] [Indexed: 11/09/2022]
Abstract
Despite the longstanding correlation between transcription and variable-(diversity)-joining (V(D)J) recombination, it is unknown whether transcription itself can direct recombinase targeting. Here we show that blockade of transcriptional elongation through the mouse T cell receptor-alpha (Tcra) locus suppressed V(alpha)-to-J(alpha) recombination and chromatin remodeling of J(alpha) segments. Transcriptional blockade also derepressed cryptic J(alpha) promoters. Our results demonstrate two key functions for transcription in Tcra locus regulation. Transcription increases the recombination of J(alpha) segments located within several kilobases of a promoter and prevents the activation of downstream promoters through transcriptional interference. These influences promote an ordered progression of Tcra locus recombination events and selection of a robust Tcra repertoire.
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Affiliation(s)
- Iratxe Abarrategui
- Department of Immunology, Duke University Medical Center, Durham, North Carolina 27710, USA
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40
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Harrow F, Ortiz BD. The TCRalpha locus control region specifies thymic, but not peripheral, patterns of TCRalpha gene expression. THE JOURNAL OF IMMUNOLOGY 2006; 175:6659-67. [PMID: 16272321 DOI: 10.4049/jimmunol.175.10.6659] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The molecular mechanisms ensuring the ordered expression of TCR genes are critical for proper T cell development. The mouse TCR alpha-chain gene locus contains a cis-acting locus control region (LCR) that has been shown to direct integration site-independent, lymphoid organ-specific expression of transgenes in vivo. However, the fine cell type specificity and developmental timing of TCRalpha LCR activity are both still unknown. To address these questions, we established a transgenic reporter model of TCRalpha LCR function that allows for analysis of LCR activity in individual cells by the use of flow cytometry. In this study we report the activation of TCRalpha LCR activity at the CD4-CD8-CD25-CD44- stage of thymocyte development that coincides with the onset of endogenous TCRalpha gene rearrangement and expression. Surprisingly, TCRalpha LCR activity appears to decrease in peripheral T cells where TCRalpha mRNA is normally up-regulated. Furthermore, LCR-linked transgene activity is evident in gammadelta T cells and B cells. These data show that the LCR has all the elements required to reliably reproduce a developmentally correct TCRalpha-like expression pattern during thymic development and unexpectedly indicate that separate gene regulatory mechanisms are acting on the TCRalpha gene in peripheral T cells to ensure its high level and fine cell type-specific expression.
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Affiliation(s)
- Faith Harrow
- Department of Biological Sciences, City University of New York, Hunter College, New York, NY 10021, USA
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41
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Hogquist KA, Baldwin TA, Jameson SC. Central tolerance: learning self-control in the thymus. Nat Rev Immunol 2005; 5:772-82. [PMID: 16200080 DOI: 10.1038/nri1707] [Citation(s) in RCA: 423] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In the past few years, there has been a flurry of discoveries and advancements in our understanding of how the thymus prepares T cells to exist at peace in normal healthy tissue: that is, to be self-tolerant. In the thymus, one of the main mechanisms of T-cell central tolerance is clonal deletion, although the selection of regulatory T cells is also important and is gaining enormous interest. In this Review, we discuss the emerging consensus about which models of clonal deletion are most physiological, and we review recent data that define the molecular mechanisms of central tolerance.
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Affiliation(s)
- Kristin A Hogquist
- Center for Immunology, Department of Laboratory Medicine and Pathology, University of Minnesota, 312 Church Street South East, Minneapolis, Minnesota 55455, USA.
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42
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Huang CY, Sleckman BP, Kanagawa O. Revision of T cell receptor {alpha} chain genes is required for normal T lymphocyte development. Proc Natl Acad Sci U S A 2005; 102:14356-61. [PMID: 16186502 PMCID: PMC1242309 DOI: 10.1073/pnas.0505564102] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To become mature alphabeta T cells, developing thymocytes must first assemble a T cell receptor (TCR) beta chain gene encoding a TCRbeta chain that forms a pre-TCR. These cells then need to generate a TCRalpha chain gene encoding a TCRalpha chain, which, when paired with the TCRbeta chain, forms a selectable alphabeta TCR. Newly generated VJalpha rearrangements that do not encode TCRalpha chains capable of forming selectable alphabeta TCRs can be excised from the chromosome and replaced with new VJalpha rearrangements. Such replacement occurs through the process of TCRalpha chain gene revision whereby a Valpha gene segment upstream of the VJalpha rearrangement is appended to a downstream Jalpha gene segment. A multistep, gene-targeting approach was used to generate a modified TCRalpha locus (TCRalpha(sJ)) with a limited capacity to undergo revision of TCRalpha chain genes. Thymocytes from mice homozygous for the TCRalpha(sJ) allele are defective in their ability to generate an alphabeta TCR. Furthermore, those thymocytes that do generate an alphabeta TCR have a diminished capacity to be positively selected, and TCRalpha(sJ/sJ) mice have significantly reduced numbers of mature alphabeta T cells. Together, these findings demonstrate that normal T cell development relies on the ability of developing thymocytes to revise their TCRalpha chain genes.
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Affiliation(s)
- Ching-Yu Huang
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63105, USA
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43
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Yamamoto R, Uenishi H, Hatsuse H, Sato E, Awata T, Yasue H, Takagaki Y. Jα-gene segment usage and the CDR3 diversity of porcine TCRα-chain cDNA clones from the PBL of a five-month-old pig and the thymus of a one-month-old pig. Mol Immunol 2005; 42:1375-83. [PMID: 15950733 DOI: 10.1016/j.molimm.2004.12.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2004] [Accepted: 12/22/2004] [Indexed: 11/19/2022]
Abstract
Porcine T-cell receptor alpha (TCRalpha)-chain cDNA clones were isolated from libraries made from two different sources, the thymus of a 1-month-old LW strain pig and the peripheral blood lymphocytes (PBL) of a 5-month-old Clawn strain pig. Among 109 cDNA clones with the Jalpha-gene segment, 44 different Jalpha-gene segments were found out of the 61 Jalpha-gene segments previously identified in the porcine germline sequence. Among the 103 complete TCRalpha-chain cDNA clones with the rearranged Valpha- and Jalpha-gene segments, 33 different Valpha-gene segments were identified, which randomly rearranged to Jalpha-gene segments indicating lack of any specific combinations between Valpha- and Jalpha-gene segments with only one exception of the same set of Jalpha-gene segments in duplicate clones. Among the cDNA clones from PBL of an individual 5-month-old Clawn strain pig, a broad distribution of the Jalpha-gene segment usage was observed over the entire Jalpha-gene cluster. The Jalpha-gene segment usage in an individual 1-month-old thymus from a LW strain pig also gave a pattern consistent with the 5-month-old pig. These distributions of the Jalpha-gene segment usage were similar to the previously reported patterns for human T-cells and those of adult murine T-cells. Among the porcine cDNA clones isolated, TCRalpha-chain CDR3 length ranged from 4 to 14 amino acids with the average being 9.35 amino acids. Present report provides groundwork for further studies on porcine TCRalpha-chain expression.
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Affiliation(s)
- Ryuji Yamamoto
- Genome Research Department, National Institute of Agrobiological Sciences, 2 Ikenodai, Tsukuba 305-8602, Japan
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44
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Xi H, Kersh GJ. Sustained early growth response gene 3 expression inhibits the survival of CD4/CD8 double-positive thymocytes. THE JOURNAL OF IMMUNOLOGY 2004; 173:340-8. [PMID: 15210792 DOI: 10.4049/jimmunol.173.1.340] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the absence of selection, CD4+, CD8+ double-positive (DP) thymocytes will die after 3-4 days. The mechanism for regulating the life span of DP cells is unknown. Previously, we demonstrated that the zinc finger transcription factor, early growth response gene 3 (Egr3), promotes proliferation during the transition from double negative (DN) to DP. In this study we demonstrate a novel role for Egr3 in controlling DP thymocyte survival in mice. Constitutive transgenic expression of Egr3 in thymocytes increases apoptosis among DP cells and shortens their survival in vitro. In addition, DP cells in Egr3 transgenic mice have poor expression of TCRalpha, and based on the predominant usage of 3' Valpha and 5' Jalpha gene segments, the low level of TCRalpha expression is a result of DP death soon after the initiation of TCRalpha rearrangements. Constitutive transgenic expression of Egr3 results in poor expression of Bcl-x(L) and the thymic isoform of retinoic acid receptor-related orphan receptor gamma (RORgammat) in DP thymocytes, two molecules that are required in DP cells for normal life span. Egr3 expression induced by pre-TCR signals in nontransgenic mice is transient and returns to background levels before RORgammat or Bcl-x(L) is induced. The data support a model in which Egr3 must be transiently induced in response to pre-TCR signals, so that the expression of the prosurvival molecules, RORgammat and Bcl-x(L), can be elevated only after the proliferative signal provided by Egr3 has subsided.
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MESH Headings
- Animals
- CD4 Antigens/analysis
- CD8 Antigens/analysis
- Cell Survival
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Early Growth Response Protein 3
- Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor
- Mice
- Mice, Transgenic
- Nuclear Receptor Subfamily 1, Group F, Member 3
- Proto-Oncogene Proteins c-bcl-2/analysis
- Receptors, Antigen, T-Cell, alpha-beta/analysis
- Receptors, Antigen, T-Cell, alpha-beta/physiology
- Receptors, Retinoic Acid/genetics
- Receptors, Thyroid Hormone/genetics
- T-Lymphocytes/physiology
- Transcription Factors/genetics
- Transcription Factors/physiology
- bcl-X Protein
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Affiliation(s)
- Hongkang Xi
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, 101 Woodruff Circle, Atlanta, GA 30322, USA
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45
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Krangel MS, Carabana J, Abbarategui I, Schlimgen R, Hawwari A. Enforcing order within a complex locus: current perspectives on the control of V(D)J recombination at the murine T-cell receptor alpha/delta locus. Immunol Rev 2004; 200:224-32. [PMID: 15242408 DOI: 10.1111/j.0105-2896.2004.00155.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
V(D)J recombination proceeds according to defined developmental programs at T-cell receptor (TCR) and immunoglobulin loci as a function of cell lineage and stage of differentiation. Although the molecular details are still lacking, such regulation is thought to occur at the level of accessibility of chromosomal recombination signal sequences to the recombinase. The unique and complex organization of the TCRalpha/delta locus poses intriguing regulatory challenges in this regard: embedded TCRalpha and TCRdelta gene segments rearrange at distinct stages of thymocyte development, there is a highly regulated progression of primary followed by secondary rearrangements involving Jalpha segments, and there are important developmental constraints on V gene segment usage. The locus therefore provides a fascinating laboratory in which to explore the basic mechanisms underlying developmental control. We provide here a current view of cis-acting mechanisms that enforce the TCRalpha/delta locus developmental program, and we emphasize the unresolved issues that command the attention of our and other laboratories.
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Affiliation(s)
- Michael S Krangel
- Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA.
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46
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Singer A, Bosselut R. CD4/CD8 coreceptors in thymocyte development, selection, and lineage commitment: analysis of the CD4/CD8 lineage decision. Adv Immunol 2004; 83:91-131. [PMID: 15135629 DOI: 10.1016/s0065-2776(04)83003-7] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Alfred Singer
- Experimental Immunology Branch, National Cancer Institute, Bethesda, Maryland 20892, USA
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47
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McCarty N, Shinohara ML, Lu L, Cantor H. Detailed analysis of gene expression during development of T cell lineages in the thymus. Proc Natl Acad Sci U S A 2004; 101:9339-44. [PMID: 15190182 PMCID: PMC438978 DOI: 10.1073/pnas.0402654101] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The genetic mechanisms that promote lineage commitment and eliminate autoreactive cells in the thymus are not well understood. To better understand this process, we have identified and quantitated transcripts in the two major thymocyte lineages by using serial analysis of gene expression. Approximately 25 genes displayed almost complete segregation to one or the other T cell lineage. Commitment to the CD4 lineage was marked by up-regulation of genes associated with increased survival and chaperone function followed by expression of genes that regulate nucleosome remodeling and T cell receptor signaling. Differentiation within the CD8 lineage, on the other hand, was marked by up-regulation of genes that regulate lymphocyte homing, followed by quenching of genes that inhibit apoptosis. Definition of differential gene expression during development of the two major thymocyte lineages will allow insight into mechanisms of T cell development after positive and negative selection.
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Affiliation(s)
- Nami McCarty
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, and Department of Pathology, Harvard Medical School, 44 Binney Street, Boston, MA 02115, USA
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48
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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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49
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Aït-Azzouzene D, Skog P, Retter M, Kouskoff V, Hertz M, Lang J, Kench J, Chumley M, Melamed D, Sudaria J, Gavin A, Martensson A, Verkoczy L, Duong B, Vela J, Nemazee D, Alfonso C. Tolerance-induced receptor selection: scope, sensitivity, locus specificity, and relationship to lymphocyte-positive selection. Immunol Rev 2004; 197:219-30. [PMID: 14962198 DOI: 10.1111/j.0105-2896.2004.0106.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Receptor editing is a mode of immunological tolerance of B lymphocytes that involves antigen-induced B-cell receptor signaling and consequent secondary immunoglobulin light chain gene recombination. This ongoing rearrangement often changes B-cell specificity for antigen, rendering the cell non-autoreactive and sparing it from deletion. We currently believe that tolerance-induced editing is limited to early stages in B-cell development and that it is a major mechanism of tolerance, with a low-affinity threshold and the potential to take place in virtually every developing B cell. The present review highlights the contributions from our laboratory over several years to elucidate these features.
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Affiliation(s)
- Djemel Aït-Azzouzene
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
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50
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Holman PO, Walsh ER, Hogquist KA. The central tolerance response to male antigen in normal mice is deletion and not receptor editing. THE JOURNAL OF IMMUNOLOGY 2004; 171:4048-53. [PMID: 14530325 DOI: 10.4049/jimmunol.171.8.4048] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
It is widely accepted that developing T cells can undergo clonal deletion in the thymus in response to a high affinity self-Ag. This is largely based on studies of TCR transgenics. However, encounter with high affinity self-Ag can also result in receptor editing in TCR transgenic models. Because all TCR transgenics display ectopic receptor expression, the tolerance mechanism that predominates in normal mice remains an open question. When self-Ag drives receptor editing during T cell development, one expects to find in-frame, self-reactive TCRalpha joins on TCR excision circles (TRECs), which are the products of secondary V/J recombination in the TCRalpha locus. Such joins are not expected if clonal deletion occurs, because the progenitor cell would be eliminated by apoptosis. To test the relative utilization of receptor editing vs clonal deletion, we determined the frequency of in-frame, male-specific joins on TRECs in male and female HYbeta transgenic mice. In comparison with female HYbeta transgenic mice, our analysis showed a lower frequency of TRECs with male-reactive V17J57 joins in male mice. Thus, it would appear that receptor editing is not a predominant tolerance mechanism for this self-Ag.
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MESH Headings
- Animals
- Clonal Deletion/genetics
- Female
- Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor
- Gene Rearrangement, beta-Chain T-Cell Antigen Receptor
- H-Y Antigen/genetics
- H-Y Antigen/immunology
- Immune Tolerance/genetics
- Lymph Nodes/cytology
- Lymph Nodes/immunology
- Lymph Nodes/metabolism
- Male
- Mice
- Mice, Knockout
- Mice, Transgenic
- RNA Editing/immunology
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Transgenes/immunology
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Affiliation(s)
- Philmore O Holman
- Department of Laboratory Medicine and Pathology and Center for Immunology, University of Minnesota, Minneapolis, MN 55455, USA
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