1
|
Anderson CK, Brossay L. The role of MHC class Ib-restricted T cells during infection. Immunogenetics 2016; 68:677-91. [PMID: 27368413 DOI: 10.1007/s00251-016-0932-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 05/22/2016] [Indexed: 01/02/2023]
Abstract
Even though major histocompatibility complex (MHC) class Ia and many Ib molecules have similarities in structure, MHC class Ib molecules tend to have more specialized functions, which include the presentation of non-peptidic antigens to non-classical T cells. Likewise, non-classical T cells also have unique characteristics, including an innate-like phenotype in naïve animals and rapid effector functions. In this review, we discuss the role of MAIT and NKT cells during infection but also the contribution of less studied MHC class Ib-restricted T cells such as Qa-1-, Qa-2-, and M3-restricted T cells. We focus on describing the types of antigens presented to non-classical T cells, their response and cytokine profile following infection, as well as the overall impact of these T cells to the immune system.
Collapse
Affiliation(s)
- Courtney K Anderson
- Department of Molecular Microbiology and Immunology, Division of Biology and Medicine, Brown University, Box G-B618, Providence, RI, 02912, USA
| | - Laurent Brossay
- Department of Molecular Microbiology and Immunology, Division of Biology and Medicine, Brown University, Box G-B618, Providence, RI, 02912, USA.
| |
Collapse
|
2
|
Nagler C, Wroblewska J. TL we meet again. Nat Immunol 2011; 12:1027-8. [PMID: 22012434 DOI: 10.1038/ni.2138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
3
|
Mucosal memory CD8⁺ T cells are selected in the periphery by an MHC class I molecule. Nat Immunol 2011; 12:1086-95. [PMID: 21964609 PMCID: PMC3197978 DOI: 10.1038/ni.2106] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 08/15/2011] [Indexed: 11/09/2022]
Abstract
The presence of immune memory at pathogen-entry sites is a prerequisite for protection. Nevertheless, the mechanisms that warrant immunity at peripheral interfaces are not understood. Here we show that the nonclassical major histocompatibility complex (MHC) class I molecule thymus leukemia antigen (TL), induced on dendritic cells interacting with CD8αα on activated CD8αβ(+) T cells, mediated affinity-based selection of memory precursor cells. Furthermore, constitutive expression of TL on epithelial cells led to continued selection of mature CD8αβ(+) memory T cells. The memory process driven by TL and CD8αα was essential for the generation of CD8αβ(+) memory T cells in the intestine and the accumulation of highly antigen-sensitive CD8αβ(+) memory T cells that form the first line of defense at the largest entry port for pathogens.
Collapse
|
4
|
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.
Collapse
|
5
|
Thymus leukemia antigen controls intraepithelial lymphocyte function and inflammatory bowel disease. Proc Natl Acad Sci U S A 2008; 105:17931-6. [PMID: 19004778 DOI: 10.1073/pnas.0808242105] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Intestinal intraepithelial lymphocytes (IEL) bear a partially activated phenotype that permits them to rapidly respond to antigenic insults. However, this phenotype also implies that IEL must be highly controlled to prevent misdirected immune reactions. It has been suggested that IEL are regulated through the interaction of the CD8alpha alpha homodimer with the thymus leukemia (TL) antigen expressed by intestinal epithelial cells. We have generated and characterized mice genetically-deficient in TL expression. Our findings show that TL expression has a critical role in maintaining IEL effector functions. Also, TL deficiency accelerated colitis in a genetic model of inflammatory bowel disease. These findings reveal an important regulatory role of TL in controlling IEL function and intestinal inflammation.
Collapse
|
6
|
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.
Collapse
|
7
|
Abstract
Technological advances in recent years have allowed for an ever-expanding ability to analyze and quantify in vivo immune responses. MHC tetramers, intracellular cytokine staining, an increasing repertoire of transgenic and "knockout" mice, and the detailed characterization of a variety of infectious models have all facilitated more precise and definitive analyses of the generation and function of cytotoxic T lymphocytes (CTL). Understanding the mechanisms behind the differentiation of effector and memory CTL is of increasing importance to develop vaccination strategies against a variety of established and emerging infectious diseases. This review focuses on recent advances in our understanding of how effector and memory CTL differentiate and survive in vivo in response to viral or bacterial infection.
Collapse
Affiliation(s)
- Matthew A Williams
- Howard Hughes Medical Institute, Department of Immunology, University of Washington, Seattle, Washington 98195, USA.
| | | |
Collapse
|
8
|
Abstract
T cell memory induced by prior infection or vaccination provides enhanced protection against subsequent microbial infections. The processes involved in generating and maintaining T cell memory are becoming better understood due to recent technological advances in identifying memory T cells and monitoring their behavior and function in vivo. Memory T cells develop in response to a progressive set of cues-starting with signals from antigen-loaded, activated antigen-presenting cells (APCs) and inflammatory mediators induced by the innate immune response, to the poorly defined subsequent signals triggered as the immune response wanes toward homeostasis. The persistence of the resting memory T cells that eventually develop is regulated by cytokines. This chapter discusses recent findings on how memory T cells develop to confer long-term protective immunity.
Collapse
Affiliation(s)
- J T Tan
- Department of Immunology, The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla, CA 92037, USA
| | | |
Collapse
|
9
|
Rocha B, Tanchot C. The Tower of Babel of CD8+ T-cell memory: known facts, deserted roads, muddy waters, and possible dead ends. Immunol Rev 2006; 211:182-96. [PMID: 16824127 DOI: 10.1111/j.0105-2896.2006.00378.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Adequate antigen stimulation can lead to permanent modifications of primed cells and to the generation of memory T cells that have astonishingly improved capacities to deal with antigen. The overall properties of memory T cells (increased survival, precocious and increased division capacities, and improved effector functions) can be used to identify this unique cell type. However, each immune response may lead to the generation of multiple primed types that do not necessarily possess all these characteristics. It is not known whether these different cell types are just side products of the immune reaction or whether they are involved in disease control. Control of different infections may involve different challenges and lead to the generation of different types of immune reactions. Our major challenge is to unravel this complexity, but we must overcome our handicapped experimental tests and our imperfect a priori definitions.
Collapse
Affiliation(s)
- Benedita Rocha
- INSERM U591, Institut Necker, Faculty of Medecine René Descartes Paris V, Paris, France.
| | | |
Collapse
|
10
|
Pardigon N, Takeda K, Saunier B, Hornung F, Gibbs J, Weisberg A, Contractor N, Kelsall B, Bennink JR, Yewdell JW. CD8 alpha alpha-mediated intraepithelial lymphocyte snatching of thymic leukemia MHC class Ib molecules in vitro and in vivo. THE JOURNAL OF IMMUNOLOGY 2006; 177:1590-8. [PMID: 16849467 DOI: 10.4049/jimmunol.177.3.1590] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thymic leukemia (TL) is a MHC class Ib molecule that interacts with CD8alphaalpha homodimers. CD8alphaalpha is abundantly expressed by intraepithelial T lymphocytes (IELs) located in close proximity to TL-expressing intestinal epithelial cells. In this study, we show that CD8alphaalpha(+) IELs "snatch" TL from the plasma membrane of TL-expressing cells and express TL in its proper orientation on their own cell surface. TL snatching is enhanced by cross-linking of IEL TCRs in a phosphatidylinositol kinase-dependent manner, and results in overall alterations to the IEL cell surface detected by enhanced binding of peanut agglutinin lectin. Induction of bowel inflammation results in the presence of TL on IELs, probably via in vivo snatching, providing the initial evidence for the interaction of CD8alphaalpha IELs with intestinal cells.
Collapse
Affiliation(s)
- Nathalie Pardigon
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
In response to infection, antigen-specific CD8+ T cells undergo massive expansion in numbers, acquire effector mechanisms, and disseminate throughout the body. The expansion phase is followed by a contraction (death) phase, where 90-95% of antigen-specific CD8+ T cells are eliminated. The remaining antigen-specific CD8+ T cells form the initial memory pool, which can be stably maintained for life. In this review, we discuss evidence that early events after infection 'program' CD8+ T cells to expand, contract, and generate memory in a fashion that is largely insensitive to the duration of infection or antigen display. Recent data demonstrate, despite numerical stability, that memory CD8+ T-cell populations undergo phenotypic and functional changes with time after immunization. However, the early suggestion that specific markers can be used to identify memory CD8+ T cells has not been supported by recent studies. Thus, we argue that specific functional characteristics, such as the ability to persist and undergo vigorous secondary expansion leading to elevated memory cell numbers, remain the best markers of 'good' memory cells. Finally, we discuss experimental approaches to manipulate and accelerate generation of CD8+ T cells with memory characteristics, and how these systems can inform both basic and applied immunology.
Collapse
|
12
|
Abstract
A critical aim of vaccine-related research is to identify the mechanisms by which memory T cells are formed and maintained over long periods of time. In recent years, we have designed experiments aimed at addressing two key questions: (i) what are the factors that maintain functionally responsive CD8+ memory cells over long periods of time, and (ii) what are the signals during the early stages of infection that drive the differentiation of long-lived CD8+ memory T cells? We have identified a role for CD4+ T cells in the generation of CD8+ T-cell-mediated protection from secondary challenge. While CD4+ T cells appear to play a role in the programme of CD8 memory, we find that they are also required for the long-term maintenance of CD8+ memory T-cell numbers and function. This property is independent of CD40-CD40L interactions, and we propose a role for CD4+ T cells in maintaining the ability of CD8+ memory T cells to respond to interleukin-7 (IL-7) and IL-15. By manipulating both the time course of infection and the timing of antigen presentation to newly recruited CD8+ T cells, we also demonstrate that the programming of effector and memory potential are at least partially distinct processes.
Collapse
Affiliation(s)
- Matthew A Williams
- Department of Immunology and Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | | | | | | |
Collapse
|
13
|
Marsden VS, Kappler JW, Marrack PC. Homeostasis of the memory T cell pool. Int Arch Allergy Immunol 2006; 139:63-74. [PMID: 16319493 DOI: 10.1159/000090000] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Indexed: 11/19/2022] Open
Abstract
Memory T cells are critical for the establishment of long-term immunity. The number of memory T cells formed at the conclusion of the primary response is strongly influenced by the number of effector T cells generated in the response, but some factors can additionally enhance the efficiency and quality of memory cell recruitment. Homeostasis of the memory T cell pool depends on cytokine-mediated regulation of cell survival and proliferation. This review discusses factors that influence both the development and the maintenance of the memory T cell pool.
Collapse
Affiliation(s)
- Vanessa S Marsden
- Integrated Department of Immunology, National Jewish Medical and Research Center, Denver, CO, USA
| | | | | |
Collapse
|
14
|
Romero P, Cerottini JC, Luescher I. On the significance of CD8 alpha alpha expression for T cell memory. Eur J Immunol 2005; 35:3092-4. [PMID: 16276480 DOI: 10.1002/eji.200535516] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Longitudinal studies on the kinetics of viral antigen specific CD8 T cell responses have led to a model whereby a relatively small subset of the primary effector CD8 T cells expanding after the first week of acute viral infection initiate a program of cell survival and differentiation into long lived memory T cells. These T cells are then critical for maintaining protective immunity to subsequent viral infection. Recent observations, using fluorescent tetramers of the MHC class Ib molecule TL, link transient expression of CD8alphaalpha homodimers on expanding primary effector CD8 T cells to the generation of memory cells. At present it is controversial what the role of CD8alphaalpha is in the generation of memory CD8 T cells. The involvement of the high affinity CD8alphaalpha ligand, the TL molecule, is not understood either. However, evidence from two viral infection models in mice, including one paper in this issue of the European Journal of Immunology, suggest a role for CD8alphaalpha in this process and call for additional research focus into these issues.
Collapse
Affiliation(s)
- Pedro Romero
- Division of Clinical Onco-Immunology, Ludwig Institute for Cancer Research, Lausanne, Switzerland.
| | | | | |
Collapse
|
15
|
Chandele A, Kaech SM. Cutting edge: memory CD8 T cell maturation occurs independently of CD8alphaalpha. THE JOURNAL OF IMMUNOLOGY 2005; 175:5619-23. [PMID: 16237050 PMCID: PMC3245648 DOI: 10.4049/jimmunol.175.9.5619] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
As memory CD8 T cells form during acute viral infection, several changes in gene expression and function occur, but little is known about the control of this process. It was reported previously that the homodimer CD8alphaalpha was involved in generating IL-7Ralphahigh memory CD8 T cell precursors, and consequently, protective memory CD8 T cells did not form in animals significantly impaired in CD8alphaalpha expression (E8(I)-/- mice). However, the precise contribution of CD8alphaalpha to sustained IL-7Ralpha expression and other memory CD8 T cell-associated changes has not been investigated. We found that IL-7Ralpha expression and generation of memory CD8 T cells that protect against secondary viral infection was considerably normal in E8(I)-/- animals. Interestingly, virus-specific CD4 T cell responses were elevated, and the relative surface levels of CD8alphabeta in activated T cells were reduced in E8(I)-/- mice compared with wild-type animals. Our results indicate that memory CD8 T cell development can occur independently of CD8alphaalpha.
Collapse
Affiliation(s)
| | - Susan M. Kaech
- Address correspondence and reprint requests to Dr. Susan M. Kaech, 300 Cedar Street, TAC S641B, Yale University School of Medicine, P.O. Box 208011, New Haven, CT 06520.
| |
Collapse
|
16
|
Zhang N, Hartig H, Dzhagalov I, Draper D, He YW. The role of apoptosis in the development and function of T lymphocytes. Cell Res 2005; 15:749-69. [PMID: 16246265 DOI: 10.1038/sj.cr.7290345] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Apoptosis plays an essential role in T cell biology. Thymocytes expressing nonfunctional or autoreactive TCRs are eliminated by apoptosis during development. Apoptosis also leads to the deletion of expanded effector T cells during immune responses. The dysregulation of apoptosis in the immune system results in autoimmunity, tumorogenesis and immunodeficiency. Two major pathways lead to apoptosis: the intrinsic cell death pathway controlled by Bcl-2 family members and the extrinsic cell death pathway controlled by death receptor signaling. These two pathways work together to regulate T lymphocyte development and function.
Collapse
Affiliation(s)
- Nu Zhang
- Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
| | | | | | | | | |
Collapse
|