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Joannou K, Baldwin TA. Destined for the intestine: thymic selection of TCRαβ CD8αα intestinal intraepithelial lymphocytes. Clin Exp Immunol 2023; 213:67-75. [PMID: 37137518 PMCID: PMC10324546 DOI: 10.1093/cei/uxad049] [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: 01/23/2023] [Revised: 03/22/2023] [Accepted: 04/30/2023] [Indexed: 05/05/2023] Open
Abstract
The immune system is composed of a variety of different T-cell lineages distributed through both secondary lymphoid tissue and non-lymphoid tissue. The intestinal epithelium is a critical barrier surface that contains numerous intraepithelial lymphocytes that aid in maintaining homeostasis at that barrier. This review focuses on T-cell receptor αβ (TCRαβ) CD8αα intraepithelial lymphocytes, and how recent advances in the field clarify how this unique T-cell subset is selected, matures, and functions in the intestines. We consider how the available evidence reveals a story of ontogeny starting from agonist selection of T cells in the thymus and finishing through the specific signaling environment of the intestinal epithelium. We conclude with how this story raises further key questions about the development of different ontogenic waves of TCRαβ CD8αα IEL and their importance for intestinal epithelial homeostasis.
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Affiliation(s)
- Kevin Joannou
- Department of Medical Microbiology and Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Troy A Baldwin
- Department of Medical Microbiology and Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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2
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Lebel MÈ, Coutelier M, Galipeau M, Kleinman CL, Moon JJ, Melichar HJ. Differential expression of tissue-restricted antigens among mTEC is associated with distinct autoreactive T cell fates. Nat Commun 2020; 11:3734. [PMID: 32709894 PMCID: PMC7381629 DOI: 10.1038/s41467-020-17544-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 07/07/2020] [Indexed: 12/12/2022] Open
Abstract
Medullary thymic epithelial cells (mTEC) contribute to the development of T cell tolerance by expressing and presenting tissue-restricted antigens (TRA), so that developing T cells can assess the self-reactivity of their antigen receptors prior to leaving the thymus. mTEC are a heterogeneous population of cells that differentially express TRA. Whether mTEC subsets induce distinct autoreactive T cell fates remains unclear. Here, we establish bacterial artificial chromosome (BAC)-transgenic mouse lines with biased mTEClo or mTEChi expression of model antigens. The transgenic lines support negative selection of antigen-specific thymocytes depending on antigen dose. However, model antigen expression predominantly by mTEClo supports TCRαβ+ CD8αα intraepithelial lymphocyte development; meanwhile, mTEChi-restricted expression preferentially induces Treg differentiation of antigen-specific cells in these models to impact control of infectious agents and tumor growth. In summary, our data suggest that mTEC subsets may have a function in directing distinct mechanisms of T cell tolerance.
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Affiliation(s)
- Marie-Ève Lebel
- Maisonneuve-Rosemont Hospital Research Center, 5415 Boulevard de l'Assomption, Montreal, QC, H1T 2M4, Canada
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, C.P. 6128, succ. Centre-ville, Montreal, QC, H3C 3J7, Canada
| | - Marie Coutelier
- The Lady Davis Institute for Medical Research, Jewish General Hospital, 3999 Côte Ste-Catherine Road Room E-542, Montreal, QC, H3T 1E2, Canada
- Department of Human Genetics, McGill University, Rm W-315, Strathcona Anatomy & Dentistry Building 3640 rue University, Montreal, QC, H3A 0C7, Canada
| | - Maria Galipeau
- Maisonneuve-Rosemont Hospital Research Center, 5415 Boulevard de l'Assomption, Montreal, QC, H1T 2M4, Canada
| | - Claudia L Kleinman
- The Lady Davis Institute for Medical Research, Jewish General Hospital, 3999 Côte Ste-Catherine Road Room E-542, Montreal, QC, H3T 1E2, Canada
- Department of Human Genetics, McGill University, Rm W-315, Strathcona Anatomy & Dentistry Building 3640 rue University, Montreal, QC, H3A 0C7, Canada
| | - James J Moon
- Center for Immunology and Inflammatory Diseases and Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Charlestown, MA, 02129, USA
| | - Heather J Melichar
- Maisonneuve-Rosemont Hospital Research Center, 5415 Boulevard de l'Assomption, Montreal, QC, H1T 2M4, Canada.
- Département de médecine, Université de Montréal, C.P. 6128, succ. Centre-ville, Montreal, QC, H3C 3J7, Canada.
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3
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McDonald BD, Jabri B, Bendelac A. Diverse developmental pathways of intestinal intraepithelial lymphocytes. Nat Rev Immunol 2019; 18:514-525. [PMID: 29717233 DOI: 10.1038/s41577-018-0013-7] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The intestinal epithelial barrier is patrolled by resident intraepithelial lymphocytes (IELs) that are involved in host defence against pathogens, wound repair and homeostatic interactions with the epithelium, microbiota and nutrients. Intestinal IELs are one of the largest populations of lymphocytes in the body and comprise several distinct subsets, the identity and lineage relationships of which have long remained elusive. Here, we review advances in unravelling the complexity of intestinal IEL populations, which comprise conventional αβ T cell receptor (TCRαβ)+ subsets, unconventional TCRαβ+ and TCRγδ+ subsets, group 1 innate lymphoid cells (ILC1s) and ILC1-like cells. Although these intestinal IEL lineages have partially overlapping effector programmes and recognition properties, they have strikingly different developmental pathways. We suggest that evolutionary pressure has driven the recurrent generation of cytolytic effector lymphocytes to protect the intestinal epithelial layer, but they may also precipitate intestinal inflammatory disorders, such as coeliac disease.
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Affiliation(s)
- Benjamin D McDonald
- Committee on Immunology, University of Chicago, Chicago, IL, USA.,Department of Pathology, University of Chicago, Chicago, IL, USA.,Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Bana Jabri
- Committee on Immunology, University of Chicago, Chicago, IL, USA.,Department of Pathology, University of Chicago, Chicago, IL, USA.,Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Albert Bendelac
- Committee on Immunology, University of Chicago, Chicago, IL, USA. .,Department of Pathology, University of Chicago, Chicago, IL, USA.
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Van Kaer L, Olivares-Villagómez D. Development, Homeostasis, and Functions of Intestinal Intraepithelial Lymphocytes. THE JOURNAL OF IMMUNOLOGY 2019; 200:2235-2244. [PMID: 29555677 PMCID: PMC5863587 DOI: 10.4049/jimmunol.1701704] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 01/25/2018] [Indexed: 12/13/2022]
Abstract
The intestine is continuously exposed to commensal microorganisms, food, and environmental agents and also serves as a major portal of entry for many pathogens. A critical defense mechanism against microbial invasion in the intestine is the single layer of epithelial cells that separates the gut lumen from the underlying tissues. The barrier function of the intestinal epithelium is supported by cells and soluble factors of the intestinal immune system. Chief among them are intestinal intraepithelial lymphocytes (iIELs), which are embedded in the intestinal epithelium and represent one of the single largest populations of lymphocytes in the body. Compared with lymphocytes in other parts of the body, iIELs exhibit unique phenotypic, developmental, and functional properties that reflect their key roles in maintaining the intestinal epithelial barrier. In this article, we review the biology of iIELs in supporting normal health and how their dysregulation can contribute to disease.
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Affiliation(s)
- Luc Van Kaer
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Danyvid Olivares-Villagómez
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232
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5
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Olivares-Villagómez D, Van Kaer L. Intestinal Intraepithelial Lymphocytes: Sentinels of the Mucosal Barrier. Trends Immunol 2018; 39:264-275. [PMID: 29221933 PMCID: PMC8056148 DOI: 10.1016/j.it.2017.11.003] [Citation(s) in RCA: 161] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 11/14/2017] [Accepted: 11/15/2017] [Indexed: 02/06/2023]
Abstract
Intestinal intraepithelial lymphocytes (IELs) are a large and diverse population of lymphoid cells that reside between the intestinal epithelial cells (IECs) that form the intestinal mucosal barrier. Although IEL biology has traditionally focused on T cells, recent studies have identified several subsets of T cell receptor (TCR)-negative IELs with intriguing properties. New insight into the development, homeostasis, and functions of distinct IEL subsets has recently been provided. Additional studies have revealed intricate interactions between different IEL subsets, reciprocal interactions between IELs and IECs, and communication of IELs with immune cells that reside outside the intestinal epithelium. We review here sentinel functions of IELs in the maintenance of the mucosal barrier integrity, as well as how dysregulated IEL responses can contribute to pathology.
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Affiliation(s)
- Danyvid Olivares-Villagómez
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA.
| | - Luc Van Kaer
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA.
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6
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Abstract
T-cell receptor affinity for self-antigen has an important role in establishing self-tolerance. Three transgenic mouse strains expressing antigens of variable affinity for the OVA transgenic-I T-cell receptor were generated to address how TCR affinity affects the efficiency of negative selection, the ability to prime an autoimmune response, and the elimination of the relevant target cell. Mice expressing antigens with an affinity just above the negative selection threshold exhibited the highest risk of developing experimental autoimmune diabetes. The data demonstrate that close to the affinity threshold for negative selection, sufficient numbers of self-reactive T cells escape deletion and create an increased risk for the development of autoimmunity.
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7
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McDonald BD, Bunker JJ, Ishizuka IE, Jabri B, Bendelac A. Elevated T cell receptor signaling identifies a thymic precursor to the TCRαβ(+)CD4(-)CD8β(-) intraepithelial lymphocyte lineage. Immunity 2014; 41:219-29. [PMID: 25131532 DOI: 10.1016/j.immuni.2014.07.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 06/27/2014] [Indexed: 12/16/2022]
Abstract
The origin and developmental pathway of intestinal T cell receptor αβ(+) CD4(-)CD8β(-) intraepithelial lymphocytes (unconventional iIELs), a major population of innate-like resident cytolytic T cells, have remained elusive. By cloning and expressing several TCRs isolated from unconventional iIELs, we identified immature CD4(lo)CD8(lo)(DP(lo))CD69(hi)PD-1(hi) thymocytes as the earliest postsignaling precursors for these cells. Although these precursors displayed multiple signs of elevated TCR signaling, a sizeable fraction of them escaped deletion to selectively engage in unconventional iIEL differentiation. Conversely, TCRs cloned from DP(lo)CD69(hi)PD-1(hi) thymocytes, a population enriched in autoreactive thymocytes, selectively gave rise to unconventional iIELs upon transgenic expression. Thus, the unconventional iIEL precursor overlaps with the DP(lo) population undergoing negative selection, indicating that, concomitant with the downregulation of both CD4 and CD8 coreceptors, a balance between apoptosis and survival signals results in outcomes as divergent as clonal deletion and differentiation to the unconventional iIEL lineage.
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Affiliation(s)
- Benjamin D McDonald
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Jeffrey J Bunker
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Isabel E Ishizuka
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Bana Jabri
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Albert Bendelac
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA.
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8
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Tomkowiak M, Ghittoni R, Teixeira M, Blanquier B, Szécsi J, Nègre D, Aubert D, Coupet CA, Brunner M, Verhoeyen E, Thoumas JL, Cosset FL, Leverrier Y, Marvel J. Generation of transgenic mice expressing EGFP protein fused to NP68 MHC class I epitope using lentivirus vectors. Genesis 2013; 51:193-200. [PMID: 23281269 DOI: 10.1002/dvg.22364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 12/11/2012] [Accepted: 12/16/2012] [Indexed: 11/09/2022]
Abstract
Immune tolerance to self-antigens is a complex process that utilizes multiple mechanisms working in concert to maintain homeostasis and prevent autoimmunity. Considerable progress in deciphering the mechanisms controlling the activation or deletion of T cells has been made by using T cell receptor (TCR) transgenic mice. One such model is the F5 model in which CD8 T cells express a TCR specific for an epitope derived from the influenza NP68 protein. Our aim was to create transgenic mouse models expressing constitutively the NP68 epitope fused to enhanced green fluorescent protein (EGFP) in order to assess unambiguously the relative levels of NP68 epitope expressed by single cells. We used a lentiviral-based approach to generate two independent transgenic mouse strains expressing the fusion protein EGFP-NP68 under the control of CAG (CMV immediate early enhancer and the chicken β-actin promoter) or spleen focus-forming virus (SFFV) promoters. Analysis of the pattern of EGFP expression in the hematopoietic compartment showed that CAG and SFFV promoters are differentially regulated during T cell development. However, both promoters drove high EGFP-NP68 expression in dendritic cells (pDCs, CD8α(+) cDCs, and CD8α(-) cDCs) from spleen or generated in vitro following differentiation from bone-marrow progenitors. NP68 epitope was properly processed and successfully presented by dendritic cells (DCs) by direct presentation and cross-presentation to F5 CD8 T cells. The models presented here are valuable tools to investigate the priming of F5 CD8 T cells by different subsets of DCs.
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Abstract
This article focuses on drug targeting to specific cellular organelles for therapeutic purposes. Drugs can be delivered to all major organelles of the cell (cytosol, endosome/lysosome, nucleus, nucleolus, mitochondria, endoplasmic reticulum, Golgi apparatus, peroxisomes and proteasomes) where they exert specific effects in those particular subcellular compartments. Delivery can be achieved by chemical (e.g., polymeric) or biological (e.g., signal sequences) means. Unidirectional targeting to individual organelles has proven to be immensely successful for drug therapy. Newer technologies that accommodate multiple signals (e.g., protein switch and virus-like delivery systems) mimic nature and allow for a more sophisticated approach to drug delivery. Harnessing different methods of targeting multiple organelles in a cell will lead to better drug delivery and improvements in disease therapy.
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10
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Clonal deletion and the fate of autoreactive thymocytes that survive negative selection. Nat Immunol 2012; 13:569-78. [PMID: 22544394 PMCID: PMC3362677 DOI: 10.1038/ni.2292] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 03/21/2012] [Indexed: 12/11/2022]
Abstract
Clonal deletion of autoreactive thymocytes is important for self-tolerance, but the intra-thymic signals that induce clonal deletion have not been clearly identified. We now report that clonal deletion during negative selection requires CD28 costimulation of autoreactive thymocytes at the CD4+CD8lo intermediate stage of differentiation. Autoreactive thymocytes were prevented from undergoing clonal deletion by either absent CD28 costimulation or transgenic over-expression of the anti-apoptotic factors Bcl-2 or Mcl-1, with surviving thymocytes differentiating into anergic T cell receptor αβ+ double negative thymocytes that preferentially migrated to the intestine where they re-expressed CD8α and were sequestered as CD8αα intraepithelial lymphocytes (IELs). This study identifies CD28 costimulation as the intrathymic signal required for clonal deletion and identifies CD8αα IELs as the developmental fate of autoreactive thymocytes that survive negative selection.
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11
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Stritesky GL, Jameson SC, Hogquist KA. Selection of self-reactive T cells in the thymus. Annu Rev Immunol 2011; 30:95-114. [PMID: 22149933 DOI: 10.1146/annurev-immunol-020711-075035] [Citation(s) in RCA: 237] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
On the whole, the healthy adaptive immune system is responsive to foreign antigens and tolerant to self. However, many individual lymphocytes have, and even require, substantial self-reactivity for their particular functions in immunity. In this review, we discuss several populations of lymphocytes that are thought to experience agonist stimulation through the T cell receptor during selection: nTreg cells, iNKT cells, nIELs, and nTh17s. We discuss the nature of this self-reactivity, how it compares with conventional T cells, and why it is important for overall immune health. We also outline molecular pathways unique to each lineage and consider possible commonalities to their development and survival.
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Affiliation(s)
- Gretta L Stritesky
- Center for Immunology and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota 55455, USA
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12
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TL and CD8αα: Enigmatic partners in mucosal immunity. Immunol Lett 2010; 134:1-6. [PMID: 20850477 DOI: 10.1016/j.imlet.2010.09.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 09/09/2010] [Indexed: 11/23/2022]
Abstract
The intestinal mucosa represents a large surface area that is in contact with an immense antigenic load. The immune system associated with the intestinal mucosa needs to distinguish between innocuous food antigens, commensal microorganisms, and pathogenic microorganisms, without triggering an exaggerated immune response that may lead to excessive inflammation and/or development of inflammatory bowel disease. The thymus leukemia (TL) antigen and CD8αα are interacting surface molecules that are expressed at the frontline of the mucosal immune system: TL is expressed in intestinal epithelial cells (IEC) whereas CD8αα is expressed in lymphocytes, known as intraepithelial lymphocytes, that reside in between the IEC. In this review we discuss the significance of the interaction between TL and CD8αα in mucosal immunity during health and disease.
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13
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Gupta G, Khan AA, Rao DN. Cell-Mediated Immune Response and Th1/Th2Cytokine Profile of B-T Constructs of F1 and V Antigen ofYersinia pestis. Scand J Immunol 2010; 71:186-98. [DOI: 10.1111/j.1365-3083.2009.02365.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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14
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Predominant clonal accumulation of CD8+ T cells with moderate avidity in the central nervous systems of Theiler's virus-infected C57BL/6 mice. J Virol 2010; 84:2774-86. [PMID: 20071578 DOI: 10.1128/jvi.01948-09] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Induction of antigen-specific CD8(+) T cells bearing a high-avidity T-cell receptor (TCR) is thought to be an important factor in antiviral and antitumor immune responses. However, the relationship between TCR diversity and functional avidity of epitope-specific CD8(+) T cells accumulating in the central nervous system (CNS) during viral infection is unknown. Hence, analysis of T-cell diversity at the clonal level is important to understand the fate and function of virus-specific CD8(+) T cells. In this study, we examined the Vbeta diversity and avidity of CD8(+) T cells specific to the predominant epitope (VP2(121-130)) of Theiler's murine encephalomyelitis virus. We found that Vbeta6(+) CD8(+) T cells, associated with epitope specificity, predominantly expanded in the CNS during viral infection. Further investigations of antigen-specific Vbeta6(+) CD8(+) T cells by CDR3 spectratyping and sequencing indicated that distinct T-cell clonotypes are preferentially increased in the CNS compared to the periphery. Among the epitope-specific Vbeta6(+) CD8(+) T cells, MGX-Jbeta1.1 motif-bearing cells, which could be found at a high precursor frequency in naïve mice, were expanded in the CNS and tightly associated with gamma interferon production. These T cells displayed moderate avidity for the cognate epitope rather than the high avidity normally observed in memory/effector T cells. Therefore, our findings provide new insights into the CD8(+) T-cell repertoire during immune responses to viral infection in the CNS.
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15
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van Wijk F, Cheroutre H. Intestinal T cells: facing the mucosal immune dilemma with synergy and diversity. Semin Immunol 2009; 21:130-8. [PMID: 19386513 DOI: 10.1016/j.smim.2009.03.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 03/23/2009] [Indexed: 12/22/2022]
Abstract
The epithelium of the gastrointestinal tract, which represents the greatest body surface area exposed to the outside environment, is confronted with a plethora of foreign and potentially harmful antigens. Consequently, the immune system of the gut faces the daunting task of distinguishing harmless dietary proteins and commensal bacteria from potentially dangerous pathogens, and of then responding accordingly. Mucosal T cells play a central role in maintaining barrier function and controlling the delicate balance between immune activation and immune tolerance. This review will focus on the unique features of mucosal T cell subsets that reside in the epithelium and lamina propria of the gut.
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Affiliation(s)
- Femke van Wijk
- Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA 92037, USA
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16
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Abstract
"The beginning of wisdom is found in doubting; by doubting we come to question, and by seeking we may come upon the truth." -Pierre Abélard. CD8 is a glycoprotein expressed on hematopoietic cells. Two isoforms of CD8, CD8alphabeta and CD8alphaalpha, have been identified that are distinct in their expression and function. Whereas CD8alphabeta serves as a T cell receptor (TCR) coreceptor to enhance the functional avidity and is constitutively expressed on MHC class I-restricted T cells, CD8alphaalpha marks T cells that are distinct from the conventional thymus-selected and MHC-restricted CD4(+) or CD8alphabeta(+) T cells. Inconsistent with a coreceptor function, CD8alphaalpha decreases antigen sensitivity of the TCR, and it can be transiently or permanently expressed on T cells, regardless of the MHC restriction of the TCR or the presence of conventional coreceptors. Together, these observations indicate that CD8alphaalpha on T cells marks a differentiation stage and that it likely functions as a TCR corepressor to negatively regulate T cell activation.
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17
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Denning TL, Granger SW, Granger S, Mucida D, Graddy R, Leclercq G, Zhang W, Honey K, Rasmussen JP, Cheroutre H, Rudensky AY, Kronenberg M. Mouse TCRalphabeta+CD8alphaalpha intraepithelial lymphocytes express genes that down-regulate their antigen reactivity and suppress immune responses. THE JOURNAL OF IMMUNOLOGY 2007; 178:4230-9. [PMID: 17371979 DOI: 10.4049/jimmunol.178.7.4230] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Mouse small intestine intraepithelial lymphocytes (IEL) that express alphabetaTCR and CD8alphaalpha homodimers are an enigmatic T cell subset, as their specificity and in vivo function remain to be defined. To gain insight into the nature of these cells, we performed global gene expression profiling using microarray analysis combined with real-time quantitative PCR and flow cytometry. Using these methods, TCRalphabeta(+)CD8alphaalpha IEL were compared with their TCRalphabeta(+)CD8beta(+) and TCRgammadelta(+) counterparts. Interestingly, TCRalphabeta(+)CD8alphaalpha IEL were found to preferentially express genes that would be expected to down-modulate their reactivity. They have a unique expression pattern of members of the Ly49 family of NK receptors and tend to express inhibitory receptors, along with some activating receptors. The signaling machinery of both TCRalphabeta(+)CD8alphaalpha and TCRgammadelta(+) IEL is constructed differently than other IEL and peripheral T cells, as evidenced by their low-level expression of the linker for activation of T cells and high expression of the non-T cell activation linker, which suppresses T cell activation. The TCRalphabeta(+)CD8alphaalpha IEL subset also has increased expression of genes that could be involved in immune regulation, including TGF-beta(3) and lymphocyte activation gene-3. Collectively, these data underscore the fact that, while TCRalphabeta(+)CD8alphaalpha IEL resemble TCRgammadelta(+) IEL, they are a unique population of cells with regulated Ag reactivity that could have regulatory function.
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Affiliation(s)
- Timothy L Denning
- Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA.
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18
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Kunisawa J, Takahashi I, Kiyono H. Intraepithelial lymphocytes: their shared and divergent immunological behaviors in the small and large intestine. Immunol Rev 2007; 215:136-53. [PMID: 17291285 DOI: 10.1111/j.1600-065x.2006.00475.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
At the front line of the body's immunological defense system, the gastrointestinal tract faces a large number of food-derived antigens, allergens, and nutrients, as well as commensal and pathogenic microorganisms. To maintain intestinal homeostasis, the gut immune system regulates two opposite immunological reactions: immune activation and quiescence. With their versatile immunological features, intraepithelial lymphocytes (IELs) play an important role in this regulation. IELs are mainly composed of T cells, but these T cells are immunologically distinct from peripheral T cells. Not only do IELs differ immunologically from peripheral T cells but they are also comprised of heterogeneous populations showing different phenotypes and immunological functions, as well as trafficking and developmental pathways. Though IELs in the small and large intestine share common features, they have also developed differences as they adjust to the two different environments. This review seeks to shed light on the immunological diversity of small and large intestinal IELs.
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Affiliation(s)
- Jun Kunisawa
- Division of Mucosal Immunology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
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19
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Abstract
The intestinal intraepithelial lymphocytes (IELs) are mostly T cells dispersed as single cells within the epithelial cell layer that surrounds the intestinal lumen. IELs are, therefore, strategically located at the interface between the antigen-rich outside world and the sterile core of the body. The intestine of higher vertebrates has further evolved to harbor numerous commensal bacteria that carry out important functions for the host, and while defensive immunity can effectively protect against the invasion of pathogens, similar immune reactions against food-derived antigens or harmless colonizing bacteria can result in unnecessary and sometimes damaging immune responses. Probably as a result of this unique dilemma imposed by the gut environment, multiple subsets of IEL have differentiated, which all display characteristics of 'activated yet resting' immune cells. Despite this common feature, IELs are heterogeneous with regard to their phenotype, ontogeny, and function. In this review, we discuss the different subtypes of IELs and highlight the distinct pathways they took that led to their unique differentiation into highly specialized effector memory T cells, which provide the most effective immune protection yet in a strictly regulated fashion to preserve the integrity and vital functions of the intestinal mucosal epithelium.
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Affiliation(s)
- Hilde Cheroutre
- The La Jolla Institute for Allergy and Immunology, San Diego, CA 92121, USA.
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20
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Cheroutre H, Kronenberg M. Mucosal T lymphocytes--peacekeepers and warriors. ACTA ACUST UNITED AC 2005; 27:147-65. [PMID: 15931528 DOI: 10.1007/s00281-005-0205-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Accepted: 04/18/2005] [Indexed: 12/30/2022]
Abstract
Normal immune homeostasis of the intestine requires peaceful coexistence with commensal flora, combined with host defense against pathogens. Perhaps as a result of this unique dilemma, distinct populations of regulatory and effector T lymphocytes are found in the lamina propria and epithelium of the intestine. Here we summarize the properties and functions of these unusual T cells, and describe the molecular and cellular interactions that lead to their development and function. Some mucosal T cells, sometimes called type a, are conventional activated/memory T cells that have received instructions to migrate to the intestine during priming by dendritic cells in the mesenteric lymph node and elsewhere. Others, however, particularly subsets residing permanently in the epithelium, are intestine-specific T cell subpopulations generated by an atypical differentiation pathway.
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Affiliation(s)
- Hilde Cheroutre
- The La Jolla Institute for Allergy and Immunology, San Diego, CA, USA.
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21
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Baldwin TA, Hogquist KA, Jameson SC. The fourth way? Harnessing aggressive tendencies in the thymus. THE JOURNAL OF IMMUNOLOGY 2005; 173:6515-20. [PMID: 15557139 DOI: 10.4049/jimmunol.173.11.6515] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
During late stages of thymic development, T cells must chose between different fates, dictated by their TCR specificity. Typically, this is thought of as a choice between three alternatives (being positive selection for useful T cells vs negative selection or neglect for harmful or useless T cells). However, there is growing evidence for a fourth alternative, in which T cells are positively selected by agonist ligands, which would normally be expected to induce T cell deletion. In this review, we will discuss where and when agonist selection is induced and whether this should be considered as a novel form of thymic selection or as an alternative differentiation state for Ag-exposed T cells.
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Affiliation(s)
- Troy A Baldwin
- Center for Immunology, Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA
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22
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Carton J, Byrne B, Madrigal-Estebas L, O'Donoghue DP, O'Farrelly C. CD4+CD8+ human small intestinal T cells are decreased in coeliac patients, with CD8 expression downregulated on intra-epithelial T cells in the active disease. Eur J Gastroenterol Hepatol 2004; 16:961-8. [PMID: 15371918 DOI: 10.1097/00042737-200410000-00003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND/OBJECTIVE The intestinal lesion of coeliac disease is thought to be initiated and exacerbated by dysregulation of local T-lymphocyte sub-populations. This study examines changes in intestinal T cells from coeliac patients, with a particular focus on CD4CD8 T cells, immunoregulatory cells normally found in relatively high proportions in the small intestine. METHODS Cells were obtained from duodenal biopsies from active and treated coeliac patients using chelating and reducing agents (epithelial layer) followed by collagenase treatment (lamina propria). Cell yield and viability were assessed and flow cytometric analysis was used to examine CD4CD8 T cells and to quantify CD8 expression. RESULTS Surprisingly, total T-cell yields in the epithelial layer did not increase in active coeliac disease although enterocyte counts decreased significantly, giving an appearance of infiltration. In active coeliac patients, CD4CD8 T cell percentages were significantly decreased in both the epithelial layer and lamina propria. Levels of CD8 expression by CD4CD8 T cells in the epithelial layer were decreased significantly in patients with active coeliac disease. CD4CD8 T cell proportions did not return to normal in treated coeliac patients whose villous architecture had responded to gluten withdrawal. CONCLUSIONS No increase of intra-epithelial lymphocytes in the coeliac lesion may require us to reconsider the definition of coeliac disease as an inflammatory condition. Low CD4CD8 populations in treated as well as untreated coeliac patients indicate that these T cells are inherently absent in individuals genetically predisposed to coeliac disease.
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Affiliation(s)
- Janet Carton
- Education and Research Centre, St Vincent's University Hospital, Dublin, Ireland
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23
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Abstract
The gastrointestinal tract is the central organ for uptake of fluids and nutrients, and at the same time it forms the main protective barrier between the sterile environment of the body and the outside world. In mammals, the intestine has further evolved to harbor a vast load of commensal bacteria that have important functions for the host. Discrimination by the host defense system of nonself from self can prevent invasion of pathogens, but equivalent responses to dietary or colonizing bacteria can lead to devastating consequences for the organism. This dilemma imposed by the gut environment has probably contributed significantly to the evolutionary drive that has led to sophisticated mechanisms and diversification of the immune system to allow for protection while maintaining the integrity of the mucosal barrier. The immense expansion and specialization of the immune system is particularly mirrored in the phylogeny, ontogeny, organization, and regulation of the adaptive intraepithelial lymphocytes, or IEL, which are key players in the unique intestinal defense mechanisms that have evolved in mammals.
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Affiliation(s)
- Hilde Cheroutre
- Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, San Diego, California 92121, USA.
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24
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Cheroutre H, Madakamutil L. Acquired and natural memory T cells join forces at the mucosal front line. Nat Rev Immunol 2004; 4:290-300. [PMID: 15057787 DOI: 10.1038/nri1333] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hilde Cheroutre
- Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, 10355 Science Center Drive, San Diego, California 92121, USA.
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25
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Saurer L, Seibold I, Rihs S, Vallan C, Dumrese T, Mueller C. Virus-Induced Activation of Self-Specific TCRαβ CD8αα Intraepithelial Lymphocytes Does Not Abolish Their Self-Tolerance in the Intestine. THE JOURNAL OF IMMUNOLOGY 2004; 172:4176-83. [PMID: 15034030 DOI: 10.4049/jimmunol.172.7.4176] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
TCRalphabeta CD8alphaalpha intestinal intraepithelial lymphocytes (IEL) represent an enigmatic subset of T cells, particularly, in regard to their potential functions and the apparent persistence of cells expressing self-specific TCR. We have used mice that are transgenic for the TCRalphabeta specific for the lymphocytic choriomeningitis virus (LCMV)-derived peptide gp33, and TCRalphabeta-transgenic mice that coexpress the gp33 Ag ubiquitously, to analyze the functional properties of TCRalphabeta CD8alphaalpha IEL in the presence, or absence, of their specific MHC-restricted Ag, and to assess the impact of molecular mimicry during a potent LCMV infection on potentially self-reactive TCRalphabeta CD8alphaalpha IEL. In this study, we show that the presence of the specific self-Ag results in reduced expression of IL-2, IFN-gamma, and IL-10 by resident TCRalphabeta CD8alphaalpha IEL while expression of mRNA for TGFbeta is not affected. We further demonstrate that despite their secluded location in the epithelium, TCRalphabeta CD8alphaalpha IEL are activated after infection of the intestinal mucosa with LCMV. Importantly, LCMV-induced activation of self-specific TCRalphabeta CD8alphaalpha IEL does not reverse their tolerance as no cytotoxic activity or up-regulated expression of proinflammatory cytokines is detected and no overt signs of autoimmunity are seen. Taken together, these results are in support of an immunoregulatory role for self-specific TCRalphabeta CD8alphaalpha in the intestinal mucosa and clearly speak against an involvement of this cell subset in inflammatory reactions and tissue destruction.
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Affiliation(s)
- Leslie Saurer
- Institute of Pathology, Division of Immunopathology, University of Bern, Bern, Switzerland
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26
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Abstract
A functional immune system requires the selection of T lymphocytes expressing receptors that are major histocompatibility complex restricted but tolerant to self-antigens. This selection occurs predominantly in the thymus, where lymphocyte precursors first assemble a surface receptor. In this review we summarize the current state of the field regarding the natural ligands and molecular factors required for positive and negative selection and discuss a model for how these disparate outcomes can be signaled via the same receptor. We also discuss emerging data on the selection of regulatory T cells. Such cells require a high-affinity interaction with self-antigens, yet differentiate into regulatory cells instead of being eliminated.
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Affiliation(s)
- Timothy K Starr
- Center for Immunology and the Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis 55455, USA.
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27
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Abstract
Intestinal intra-epithelial lymphocytes (iIELs) are a major lymphocyte population, reside in close proximity to the intestinal lumen and are conserved throughout vertebrate evolution. iIELs consist of several unique T-cell phenotypes and express both non-rearranged innate immune receptors and rearranged adaptive immune receptors. The ligands for the innate immune receptors on iIELs, such as NKG2D (natural killer-cell receptor), often bind to non-classical MHC class I molecules, such as the human MHC class I-related molecules MICA or MICB. These ligands costimulate T-cell receptor (TCR)-mediated signaling. In most cases, the MHC molecules that bind to the TCR are still unknown. However, recent efforts to understand the MHC molecules that are involved in the development of and antigen recognition by iIELs have revealed several important results. Here, we focus systematically on recent developments in innate immunity and in TCR recognition of different subtypes of iIELs by various MHC molecules.
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Affiliation(s)
- Gobardhan Das
- Room #3335, Bld-JR2, Aventis Pharmaceuticals, 202-206 North, Bridgewater, NJ 08807, USA
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28
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Leishman AJ, Gapin L, Capone M, Palmer E, MacDonald HR, Kronenberg M, Cheroutre H. Precursors of functional MHC class I- or class II-restricted CD8alphaalpha(+) T cells are positively selected in the thymus by agonist self-peptides. Immunity 2002; 16:355-64. [PMID: 11911821 DOI: 10.1016/s1074-7613(02)00284-4] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The origin and specificity of alphabeta TCR(+) T cells that express CD8alphaalpha have been controversial issues. Here we provide direct evidence that precursors of functional CD8alphaalpha T cells are positively selected in the thymus in the presence of agonist self-peptides. Like conventional positive selection, this agonist selection process requires functional TCR alpha-CPM, whereas it is independent of CD8beta expression. Furthermore, CD8alphaalpha expression on mature, agonist-selected T cells does not imply selection by MHC class I, and CD8alphaalpha(+) T cells can be either class I or class II restricted. Our data define a distinct agonist-dependent, positive selection process in the thymus, and they suggest a function for CD8alphaalpha distinct from the conventional TCR coreceptor function of CD8alphabeta or CD4.
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Affiliation(s)
- Andrew J Leishman
- La Jolla Institute for Allergy and Immunology, 10355 Science Center Drive, San Diego, CA 92121, USA
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29
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Leishman AJ, Naidenko OV, Attinger A, Koning F, Lena CJ, Xiong Y, Chang HC, Reinherz E, Kronenberg M, Cheroutre H. T cell responses modulated through interaction between CD8alphaalpha and the nonclassical MHC class I molecule, TL. Science 2001; 294:1936-9. [PMID: 11729321 DOI: 10.1126/science.1063564] [Citation(s) in RCA: 195] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The thymus leukemia antigen (TL) is a nonclassical class I molecule, expressed abundantly on intestinal epithelial cells. We show that, in contrast to other major histocompatibility complex (MHC) class I molecules that bind CD8alphabeta, TL preferentially binds the homotypic form of CD8alpha (CD8alphaalpha). Thus, TL tetramers react specifically to CD8alphaalpha-expressing cells, including most intestinal intraepithelial lymphocytes. Compared with CD8alphabeta, which recognizes the same MHC as the T cell receptor (TCR) and thus acts as a TCR coreceptor, high-affinity binding of CD8alphaalpha to TL modifies responses mediated by TCR recognition of antigen presented by distinct MHC molecules. These findings define a novel mechanism of lymphocyte regulation through CD8alphaalpha and MHC class I.
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Affiliation(s)
- A J Leishman
- Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, 10355 Science Center Drive, San Diego, CA 92121, USA
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30
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Podd BS, Aberg C, Kudla KL, Keene L, Tobias E, Camerini V. MHC class I allele dosage alters CD8 expression by intestinal intraepithelial lymphocytes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:2561-8. [PMID: 11509596 DOI: 10.4049/jimmunol.167.5.2561] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The development of TCR alphabeta(+), CD8alphabeta(+) intestinal intraepithelial lymphocytes (IEL) is dependent on MHC class I molecules expressed in the thymus, while some CD8alphaalpha(+) IEL may arise independently of MHC class I. We examined the influence of MHC I allele dosage on the development CD8(+) T cells in RAG 2(-/-) mice expressing the H-2D(b)-restricted transgenic TCR specific for the male, Smcy-derived H-Y Ag (H-Y TCR). IEL in male mice heterozygous for the restricting (H-2D(b)) and nonrestricting (H-2D(d)) MHC class I alleles (MHC F(1)) were composed of a mixture of CD8alphabeta(+) and CD8alphaalpha(+) T cells, while T cells in the spleen were mostly CD8alphabeta(+). This was unlike IEL in male mice homozygous for H-2D(b), which had predominantly CD8alphaalpha(+) IEL and few mostly CD8(-) T cells in the spleen. Our results demonstrate that deletion of CD8alphabeta(+) cells in H-Y TCR male mice is dependent on two copies of H-2D(b), whereas the generation of CD8alphaalpha(+) IEL requires only one copy. The existence of CD8alphabeta(+) and CD8alphaalpha(+) IEL in MHC F(1) mice suggests that their generation is not mutually exclusive in cells with identical TCR. Furthermore, our data imply that the level of the restricting MHC class I allele determines a threshold for conventional CD8alphabeta(+) T cell selection in the thymus of H-Y TCR-transgenic mice, whereas the development of CD8alphaalpha(+) IEL is dependent on, but less sensitive to, this MHC class I allele.
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Affiliation(s)
- B S Podd
- Department of Pediatrics and Beirne B. Carter Center for Immunology, University of Virginia Health Sciences Center, Charlottesville, VA 22908, USA
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31
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Matsunaga T, Rahman A. In search of the origin of the thymus: the thymus and GALT may be evolutionarily related. Scand J Immunol 2001; 53:1-6. [PMID: 11169200 DOI: 10.1046/j.1365-3083.2001.00854.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The thymus is the major primary immune tissue for the production of functional T lymphocytes in vertebrates. However, its evolutionary origin is unknown. It has recently been shown that the generation of local T cells also occurs in gut-associated lymphoid tissues (GALT). This suggests that the thymus and GALT have similar functions and that they might be evolutionarily related. We discuss the possibility that the thymus may have evolved from mucosa-associated lymphoid tissues (MALT) located in the gill region in early vertebrates. Various facts supporting this proposal are summarized.
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Affiliation(s)
- T Matsunaga
- Department of Immunology, Umeå University, Umeå, SE-901 85, Sweden
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32
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Poussier P, Ning T, Chen J, Banerjee D, Julius M. Intestinal inflammation observed in IL-2R/IL-2 mutant mice is associated with impaired intestinal T lymphopoiesis. Gastroenterology 2000; 118:880-91. [PMID: 10784587 DOI: 10.1016/s0016-5085(00)70174-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND & AIMS Although interleukin (IL)-2(-/-) and IL-2Ralpha(-/-) mice develop inflammatory bowel disease, IL-2Rbeta(-/-) animals are apparently free of gut pathology. Intraintestinal T lymphopoiesis is reported to be impaired in IL-2Rbeta(-/-) mice; we have determined whether this characteristic correlated with the apparent resistance of this mutant strain to intestinal inflammation. This led us to reassess intraintestinal T lymphopoiesis in these 3 mutant strains. METHODS Intestinal histology and intraintestinal T lymphopoiesis were analyzed in unmanipulated mutant mice and in athymic and euthymic radiation chimeras reconstituted with bone marrow derived from IL-2(-/-), IL-2Ralpha(-/-), and IL-2Rbeta(-/-) donors. RESULTS Intraintestinal T lymphopoiesis was ablated in the 3 mutant strains and was associated with cryptopatch abnormalities. The intestinal mucosa of mice reconstituted with lymphocytes from IL-2Rbeta(-/-) mice exhibited lesions of both the small and large bowel similar to those observed in the early stages of human gluten enteropathy and acute ulcerative colitis, respectively. Analysis of euthymic and athymic bone marrow radiation chimeras indicated that T cells located in the intestinal mucosa of unmanipulated IL-2(-/-), IL-2Ralpha(-/-), and IL-2Rbeta(-/-) mice are of thymic origin. CONCLUSIONS Null mutations at IL-2/IL-2Ralpha and beta loci differentially affect intraintestinal and intrathymic T lymphopoiesis. These conditions are associated with lesions of intestinal inflammation that are mediated by thymus-derived T cells.
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Affiliation(s)
- P Poussier
- Arthritis and Immune Disorder Research Centre, Toronto, University of Toronto, Toronto, Ontario, Canada
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34
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Gapin L, Cheroutre H, Kronenberg M. Cutting Edge: TCRαβ+ CD8αα+ T Cells Are Found in Intestinal Intraepithelial Lymphocytes of Mice That Lack Classical MHC Class I Molecules. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.8.4100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
TCRαβ+ intestinal intraepithelial lymphocytes (IEL) can express either the typical CD8αβ heterodimer or an unusual CD8αα homodimer. Both types of CD8+ IEL require class I molecules for their differentiation, since they are absent in β2m−/− mice. To gain insight into the role of class I molecules in forming TCRαβ+ CD8+ IEL populations, we have analyzed the IEL in mice deficient for either TAP, β2m, CD1, or K and D. We find that K−/−D−/− mice have TCRαβ+ CD8αα+ IEL, although they are deficient for TCRαβ+ CD8αβ+ cells. This indicates that at least some TCRαβ+ CD8αα+ IEL require only nonclassical class I molecules for their development. Surprisingly, the TCRαβ+ CD8αα+ IEL are significantly increased in K−/−D−/− mice, suggesting a complex interaction between CD8+ IEL and class I molecules that might include direct or indirect negative regulation by K and D, as well as positive effects mediated by nonclassical class I molecules.
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Affiliation(s)
- Laurent Gapin
- Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, San Diego, CA 92121
| | - Hilde Cheroutre
- Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, San Diego, CA 92121
| | - Mitchell Kronenberg
- Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, San Diego, CA 92121
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35
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Park SH, Guy-Grand D, Lemonnier FA, Wang CR, Bendelac A, Jabri B. Selection and expansion of CD8alpha/alpha(1) T cell receptor alpha/beta(1) intestinal intraepithelial lymphocytes in the absence of both classical major histocompatibility complex class I and nonclassical CD1 molecules. J Exp Med 1999; 190:885-90. [PMID: 10499927 PMCID: PMC2195634 DOI: 10.1084/jem.190.6.885] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/1999] [Accepted: 07/13/1999] [Indexed: 11/10/2022] Open
Abstract
Intestinal intraepithelial lymphocytes (IELs) in mice include two main subsets of TCR-alpha/beta(1) cells which differ functionally and ontogenically from each other. One expresses the CD8alpha/alpha homodimer, whereas the other expresses the CD8alpha/beta heterodimer. Although the presence of all CD8(+)TCR-alpha/beta(1) IELs is dependent on beta2-microglobulin molecules, the nature of the major histocompatibility complex (MHC) class I molecules recognized by the CD8alpha/alpha and the CD8alpha/beta(1) subsets has remained elusive. Using mutant mice lacking the expression of both H2-K(b) and H2-D(b), we show that the CD8alpha/beta(1)TCR-alpha/beta(1) subset is dependent on K or D molecules, whereas the CD8alpha/alpha(1)TCR-alpha/beta(1) subset is independent of classical MHC class I molecules. Furthermore, the CD8alpha/alpha(1) cells are conserved in mice lacking expression of CD1, a nonclassical MHC class I-like molecule previously proposed to be a potential ligand for IELs. Using transporter associated with antigen processing (TAP)-deficient mice, this cell population can be further separated into a TAP-dependent and a TAP-independent subset, suggesting either the recognition of two nonclassical MHC-like molecules, only one of which is TAP dependent, or the involvement of a single nonclassical MHC-like molecule that is only partially TAP dependent. These findings demonstrate that CD8alpha/beta(1)TCR-alpha/beta(1) IELs are restricted by H-2K and H-2D molecules, whereas the unusual subset of CD8alpha/alpha(1)TCR-alpha/beta(1) resident IELs recognize nonclassical MHC class I-like molecules that are distinct from CD1.
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Affiliation(s)
- Se-Ho Park
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544
| | | | | | - Chyung-Ru Wang
- Department of Pathology, Gwenn Knapp Center for Lupus and Immunological Research, University of Chicago, Chicago, Illinois 60637
| | - Albert Bendelac
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544
| | - Bana Jabri
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544
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