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Radwan J, Kohi C, Ejsmond M, Paganini J, Pontarotti P. Integration of the immune memory into the pathogen-driven MHC polymorphism hypothesis. HLA 2023; 102:653-659. [PMID: 37688391 DOI: 10.1111/tan.15216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 06/01/2023] [Accepted: 08/26/2023] [Indexed: 09/10/2023]
Abstract
Major histocompatibility complex (MHC) genes (referred to as human leukocyte antigen or HLA in humans) are a key component of vertebrate immune systems, coding for proteins which present antigens to T-cells. These genes are outstanding in their degree of polymorphism, with important consequences for human and animal health. The polymorphism is thought to arise from selection pressures imposed by pathogens on MHC allomorphs, which differ in their antigen-binding capacity. However, the existing theory has not considered MHC selection in relation to the formation of immune memory. In this paper, we argue that this omission limits our understanding of the evolution of MHC polymorphism and its role in disease. We review recent evidence that has emerged from the massive research effort related to the SARS-CoV-2 pandemics, and which provides new evidence for the role of MHC in shaping immune memory. We then discuss why the inclusion of immune memory within the existing theory may have non-trivial consequence for our understanding of the evolution of MHC polymorphism. Finally, we will argue that neglecting immune memory hinders our interpretation of empirical findings, and postulate that future studies focusing on pathogen-driven MHC selection would benefit from stratifying the available data according to the history of infection (and vaccination, if relevant).
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Affiliation(s)
- Jacek Radwan
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Chirine Kohi
- MEPHI, Aix Marseille Université, Marseille, France
| | - Maciej Ejsmond
- Institute of Environmental Sciences, Jagiellonian University, Krakow, Poland
| | | | - Pierre Pontarotti
- MEPHI, Aix Marseille Université, Marseille, France
- Institute of Environmental Sciences, Jagiellonian University, Krakow, Poland
- SNC 5039 CNRS, Marseille, France
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2
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Meehan GR, Thomas R, Al Khabouri S, Wehr P, Hilkens CM, Wraith DC, Sieghart D, Bonelli M, Nagy G, Garside P, Tough DF, Lewis HD, Brewer JM. Preclinical models of arthritis for studying immunotherapy and immune tolerance. Ann Rheum Dis 2021; 80:1268-1277. [PMID: 34380700 PMCID: PMC8458054 DOI: 10.1136/annrheumdis-2021-220043] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/27/2021] [Indexed: 02/06/2023]
Abstract
Increasingly earlier identification of individuals at high risk of rheumatoid arthritis (RA) (eg, with autoantibodies and mild symptoms) improves the feasibility of preventing or curing disease. The use of antigen-specific immunotherapies to reinstate immunological self-tolerance represent a highly attractive strategy due to their potential to induce disease resolution, in contrast to existing approaches that require long-term treatment of underlying symptoms. Preclinical animal models have been used to understand disease mechanisms and to evaluate novel immunotherapeutic approaches. However, models are required to understand critical processes supporting disease development such as the breach of self-tolerance that triggers autoimmunity and the progression from asymptomatic autoimmunity to joint pain and bone loss. These models would also be useful in evaluating the response to treatment in the pre-RA period. This review proposes that focusing on immune processes contributing to initial disease induction rather than end-stage pathological consequences is essential to allow development and evaluation of novel immunotherapies for early intervention. We will describe and critique existing models in arthritis and the broader field of autoimmunity that may fulfil these criteria. We will also identify key gaps in our ability to study these processes in animal models, to highlight where further research should be targeted.
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Affiliation(s)
- Gavin R Meehan
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Ranjeny Thomas
- University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, Queensland, Australia
| | - Shaima Al Khabouri
- Division of Rheumatology, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Pascale Wehr
- University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, Queensland, Australia
| | - Catharien Mu Hilkens
- Translational & Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - David C Wraith
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Daniela Sieghart
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Michael Bonelli
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - György Nagy
- Department of Rheumatology & Clinical Immunology, Semmelweis University, Budapest, Hungary.,Department of Genetics, Cell and Immunobiology, Semmelweis University, Budapest, Hungary
| | - Paul Garside
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - David F Tough
- GlaxoSmithKline Research and Development, Stevenage, Hertfordshire, UK
| | - Huw D Lewis
- GlaxoSmithKline Research and Development, Stevenage, Hertfordshire, UK
| | - James M Brewer
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
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3
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Matczyńska D, Sypniewski D, Gałka S, Sołtysik D, Loch T, Nowak E, Smorąg Z, Bednarek I. Analysis of swine leukocyte antigen class I gene profiles and porcine endogenous retrovirus viremia level in a transgenic porcine herd inbred for xenotransplantation research. J Vet Sci 2018; 19:384-392. [PMID: 29366300 PMCID: PMC5974520 DOI: 10.4142/jvs.2018.19.3.384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 12/29/2017] [Accepted: 01/20/2018] [Indexed: 11/26/2022] Open
Abstract
Molecular characterization of swine leukocyte antigen (SLA) genes is important for elucidating the immune responses between swine-donor and human-recipient in xenotransplantation. Examination of associations between alleles of SLA class I genes, type of pig genetic modification, porcine endogenous retrovirus (PERV) viral titer, and PERV subtypes may shed light on the nature of xenograft acceptance or rejection and the safety of xenotransplantation. No significant difference in PERV gag RNA level between transgenic and non-transgenic pigs was noted; likewise, the type of applied transgene had no impact on PERV viremia. SLA-1 gene profile type may correspond with PERV level in blood and thereby influence infectiveness. Screening of pigs should provide selection of animals with low PERV expression and exclusion of specimens with PERV-C in the genome due to possible recombination between A and C subtypes, which may lead to autoinfection. Presence of PERV-C integrated in the genome was detected in 31.25% of specimens, but statistically significant increased viremia in specimens with PERV-C was not observed. There is a need for multidirectional molecular characterization (SLA typing, viremia estimation, and PERV subtype screening) of animals intended for xenotransplantation research in the interest of xeno-recipient safety.
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Affiliation(s)
- Daria Matczyńska
- Department of Biotechnology and Genetic Engineering, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia in Katowice, 41-200 Sosnowiec, Poland
| | - Daniel Sypniewski
- Department of Biotechnology and Genetic Engineering, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia in Katowice, 41-200 Sosnowiec, Poland
| | - Sabina Gałka
- Department of Biotechnology and Genetic Engineering, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia in Katowice, 41-200 Sosnowiec, Poland
| | - Dagna Sołtysik
- Department of Biotechnology and Genetic Engineering, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia in Katowice, 41-200 Sosnowiec, Poland
| | - Tomasz Loch
- Department of Biotechnology and Genetic Engineering, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia in Katowice, 41-200 Sosnowiec, Poland
| | - Ewa Nowak
- Department of Biotechnology and Genetic Engineering, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia in Katowice, 41-200 Sosnowiec, Poland
| | - Zdzisław Smorąg
- Department of Animal Reproduction Biotechnology, National Research Institute of Animal Production, 32-083 Balice, Poland
| | - Ilona Bednarek
- Department of Biotechnology and Genetic Engineering, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia in Katowice, 41-200 Sosnowiec, Poland
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4
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Attaf M, Huseby E, Sewell AK. αβ T cell receptors as predictors of health and disease. Cell Mol Immunol 2015; 12:391-9. [PMID: 25619506 PMCID: PMC4496535 DOI: 10.1038/cmi.2014.134] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 12/17/2014] [Indexed: 02/08/2023] Open
Abstract
The diversity of antigen receptors and the specificity it underlies are the hallmarks of the cellular arm of the adaptive immune system. T and B lymphocytes are indeed truly unique in their ability to generate receptors capable of recognizing virtually any pathogen. It has been known for several decades that T lymphocytes recognize short peptides derived from degraded proteins presented by major histocompatibility complex (MHC) molecules at the cell surface. Interaction between peptide-MHC (pMHC) and the T cell receptor (TCR) is central to both thymic selection and peripheral antigen recognition. It is widely assumed that TCR diversity is required, or at least highly desirable, to provide sufficient immune coverage. However, a number of immune responses are associated with the selection of predictable, narrow, or skewed repertoires and public TCR chains. Here, we summarize the current knowledge on the formation of the TCR repertoire and its maintenance in health and disease. We also outline the various molecular mechanisms that govern the composition of the pre-selection, naive and antigen-specific TCR repertoires. Finally, we suggest that with the development of high-throughput sequencing, common TCR 'signatures' raised against specific antigens could provide important diagnostic biomarkers and surrogate predictors of disease onset, progression and outcome.
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Affiliation(s)
- Meriem Attaf
- Cardiff University School of Medicine, Cardiff, UK
| | - Eric Huseby
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, USA
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Osborne AJ, Pearson J, Negro SS, Chilvers BL, Kennedy MA, Gemmell NJ. Heterozygote advantage at MHC DRB may influence response to infectious disease epizootics. Mol Ecol 2015; 24:1419-32. [PMID: 25728376 DOI: 10.1111/mec.13128] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 02/18/2015] [Accepted: 02/20/2015] [Indexed: 12/17/2022]
Abstract
The effect of MHC polymorphism on individual fitness variation in the wild remains equivocal; however, much evidence suggests that heterozygote advantage is a major determinant. To understand the contribution of MHC polymorphism to individual disease resistance or susceptibility in natural populations, we investigated two MHC class II B loci, DQB and DRB, in the New Zealand sea lion (NZSL, Phocarctos hookeri). The NZSL is a threatened species which is unusually susceptible to death by bacterial infection at an early age; it has suffered three bacterial induced epizootics resulting in high mortality levels of young pups since 1997. The MHC DQB and DRB haplotypes of dead NZSL pups with known cause of death (bacteria, enteritis or trauma) were sequenced and reconstructed, compared to pups that survived beyond 2 months of age, and distinct MHC DRB allele frequency and genotype differences were identified. Two findings were striking: (i) one DRB allele was present only in dead pups, and (ii) one heterozygous DRB genotype, common in live pups, was absent from dead pups. These results are consistent with some functional relationship with these variants and suggest heterozygote advantage is operating at DRB. We found no association between heterozygosity and fitness at 17 microsatellite loci, indicating that general heterozygosity is not responsible for the effect on fitness detected here. This result may be a consequence of recurrent selection by multiple pathogen assault over recent years and highlights the importance of heterozygote advantage at MHC as a potential mechanism for fitness differences in wild populations.
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Affiliation(s)
- Amy J Osborne
- Department of Anatomy, University of Otago, PO Box 913, Dunedin, 9054, New Zealand; Department of Pathology, University of Otago, Christchurch, 8140, New Zealand
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6
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Osborne AJ, Zavodna M, Chilvers BL, Robertson BC, Negro SS, Kennedy MA, Gemmell NJ. Extensive variation at MHC DRB in the New Zealand sea lion (Phocarctos hookeri) provides evidence for balancing selection. Heredity (Edinb) 2013; 111:44-56. [PMID: 23572124 PMCID: PMC3692317 DOI: 10.1038/hdy.2013.18] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2012] [Revised: 12/20/2012] [Accepted: 01/28/2013] [Indexed: 11/09/2022] Open
Abstract
Marine mammals are often reported to possess reduced variation of major histocompatibility complex (MHC) genes compared with their terrestrial counterparts. We evaluated diversity at two MHC class II B genes, DQB and DRB, in the New Zealand sea lion (Phocarctos hookeri, NZSL) a species that has suffered high mortality owing to bacterial epizootics, using Sanger sequencing and haplotype reconstruction, together with next-generation sequencing. Despite this species' prolonged history of small population size and highly restricted distribution, we demonstrate extensive diversity at MHC DRB with 26 alleles, whereas MHC DQB is dimorphic. We identify four DRB codons, predicted to be involved in antigen binding, that are evolving under adaptive evolution. Our data suggest diversity at DRB may be maintained by balancing selection, consistent with the role of this locus as an antigen-binding region and the species' recent history of mass mortality during a series of bacterial epizootics. Phylogenetic analyses of DQB and DRB sequences from pinnipeds and other carnivores revealed significant allelic diversity, but little phylogenetic depth or structure among pinniped alleles; thus, we could neither confirm nor refute the possibility of trans-species polymorphism in this group. The phylogenetic pattern observed however, suggests some significant evolutionary constraint on these loci in the recent past, with the pattern consistent with that expected following an epizootic event. These data may help further elucidate some of the genetic factors underlying the unusually high susceptibility to bacterial infection of the threatened NZSL, and help us to better understand the extent and pattern of MHC diversity in pinnipeds.
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Affiliation(s)
- A J Osborne
- Centre for Reproduction and Genomics, Department of Anatomy, University of Otago, Dunedin, New Zealand.
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7
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Day EB, Charlton KL, La Gruta NL, Doherty PC, Turner SJ. Effect of MHC class I diversification on influenza epitope-specific CD8+ T cell precursor frequency and subsequent effector function. THE JOURNAL OF IMMUNOLOGY 2011; 186:6319-28. [PMID: 21536802 DOI: 10.4049/jimmunol.1000883] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Earlier studies of influenza-specific CD8(+) T cell immunodominance hierarchies indicated that expression of the H2K(k) MHC class I allele greatly diminishes responses to the H2D(b)-restriced D(b)PA(224) epitope (acid polymerase, residues 224-233 complexed with H2D(b)). The results suggested that the presence of H2K(k) during thymic differentiation led to the deletion of a prominent Vβ7(+) subset of D(b)PA(224)-specific TCRs. The more recent definition of D(b)PA(224)-specific TCR CDR3β repertoires in H2(b) mice provides a new baseline for looking again at this possible H2K(k) effect on D(b)PA(224)-specific TCR selection. We found that immune responses to several H2D(b)- and H2K(b)-restricted influenza epitopes were indeed diminished in H2(bxk) F(1) versus homozygous mice. In the case of D(b)PA(224), lower numbers of naive precursors were part of the explanation, though a similar decrease in those specific for the D(b)NP(366) epitope did not affect response magnitude. Changes in precursor frequency were not associated with any major loss of TCR diversity and could not fully account for the diminished D(b)PA(224)-specific response. Further functional and phenotypic characterization of influenza-specific CD8(+) T cells suggested that the expansion and differentiation of the D(b)PA(224)-specific set is impaired in the H2(bxk) F(1) environment. Thus, the D(b)PA(224) response in H2(bxk) F(1) mice is modulated by factors that affect the generation of naive epitope-specific precursors and the expansion and differentiation of these T cells during infection, rather than clonal deletion of a prominent Vβ7(+) subset. Such findings illustrate the difficulties of predicting and defining the effects of MHC class I diversification on epitope-specific responses.
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Affiliation(s)
- E Bridie Day
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3010, Australia
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8
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Rudd BD, Venturi V, Davenport MP, Nikolich-Zugich J. Evolution of the antigen-specific CD8+ TCR repertoire across the life span: evidence for clonal homogenization of the old TCR repertoire. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2011; 186:2056-2064. [PMID: 21248263 PMCID: PMC4119821 DOI: 10.4049/jimmunol.1003013] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Defects in T cell responses against pathogens and reduced diversity of TCRs have been described at both extremes of the life span. Yet, we still lack information on how Ag-specific T cell populations are maintained and/or altered from birth to old age. In this study, for the first time to our knowledge, we provide insight into Ag-specific TCR repertoire changes over the life span at the single-cell level. We have examined the TCR diversity of the primary CD8(+) T cell response to the immunodominant HSV-1 epitope HSV glycoprotein B 495-502 (HSV gB(498-505); SSIEFARL) (gB-8p) in neonatal, adult, and old C57BL/6 mice. The global distinctive features of the gB-8p-specific TCR repertoire were preserved in mice of different ages. However, both old and especially neonatal mice exhibited significant decreases in TCR diversity compared with that of adult mice. Still, although the neonatal Ag-specific repertoire comprised expectedly shorter germline-biased CDR3β lengths, the repertoire was surprisingly complex, and only a minority of responding cells lacked random nucleotide additions. Changes with aging included increased use of the already dominant TCRVβ10 family, a trend for lower content of the TCR containing the germline WG motif in the CDR3, and a remarkable sharing of one dominant clonotype between individual old mice, implying operation of selective mechanisms. Implications for the rational design of vaccines for neonates and the elderly are discussed.
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MESH Headings
- Animals
- Animals, Newborn
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/virology
- Cellular Senescence/genetics
- Cellular Senescence/immunology
- Clone Cells
- Epitopes, T-Lymphocyte/genetics
- Epitopes, T-Lymphocyte/immunology
- Evolution, Molecular
- Herpesvirus 1, Human/immunology
- Immunodominant Epitopes/genetics
- Immunodominant Epitopes/immunology
- Immunoglobulin Variable Region/biosynthesis
- Immunoglobulin Variable Region/genetics
- Longevity/genetics
- Longevity/immunology
- Male
- Mice
- Mice, Inbred C57BL
- Peptide Fragments/biosynthesis
- Peptide Fragments/genetics
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Vaccinia virus/genetics
- Vaccinia virus/immunology
- Viral Envelope Proteins/biosynthesis
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Affiliation(s)
- Brian D. Rudd
- Department of Immunobiology and, the Arizona Center on Aging, University of Arizona College of Medicine, Tucson, AZ 85724 and the BIO-5 Institute, University of Arizona, Tucson ,AZ 85719
| | - Vanessa Venturi
- Computational Biology Unit, University of New South Wales, Kensington, New South Wales 2052, Australia
| | - Miles P. Davenport
- Complex Systems in Biology Group, Centre for Vascular Research, University of New South Wales, Kensington, New South Wales 2052, Australia
| | - Janko Nikolich-Zugich
- Department of Immunobiology and, the Arizona Center on Aging, University of Arizona College of Medicine, Tucson, AZ 85724 and the BIO-5 Institute, University of Arizona, Tucson ,AZ 85719
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9
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MHC class II variation in the endangered European mink Mustela lutreola (L. 1761)—consequences for species conservation. Immunogenetics 2009; 61:281-8. [PMID: 19263000 DOI: 10.1007/s00251-009-0362-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Accepted: 02/13/2009] [Indexed: 10/21/2022]
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10
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Fulop T, Franceschi C, Hirokawa K, Pawelec G. Age-associated T-cell Clonal Expansions (TCE) in vivo—Implications for Pathogen Resistance. HANDBOOK ON IMMUNOSENESCENCE 2008. [PMCID: PMC7114977 DOI: 10.1007/978-1-4020-9063-9_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Age-related T-cell clonal expansions (TCE) are an incompletely understood disturbance in T-cell homeostasis found frequently in old humans and experimental animals. These accumulations of CD8 T-cells have the potential to distort T-cell population balance and reduce T-cell repertoire diversity above and beyond the changes seen in the aging of T-cell pool in the absence of TCE. This chapter discusses our current knowledge of the role of these expansions in health and disease, with a special focus on their influence upon immune defense against infectious diseases.
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Affiliation(s)
- Tamas Fulop
- Research Center on Aging, Department of Medicine, Immunology Graduate Programme, Faculty of Medicine, University of Sherbrooke, 1036 Rue Belvedere, J1H 4C4 Sherbrooke, Quebec Canada
| | - Claudio Franceschi
- Department of Experimental Pathalogy, CIG Interdepartmental Center “L. Galvani” University of Bologna, Via San Giacomo 12, 40126 Bologna, Italy
| | - Katsuiku Hirokawa
- Institute for Health and Life Sciences, 4-6-22 Kohinato, Bunkyo-ku, Tokyo, 112-0006 Japan
| | - Graham Pawelec
- ZMF - Zentrum Med. Forschung Abt. Transplant./ Immunologie, University of Tübingen, Waldhörnlestr. 22, 72072 Tübingen, Germany
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11
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Lang A, Brien JD, Messaoudi I, Nikolich-Zugich J. Age-related dysregulation of CD8+ T cell memory specific for a persistent virus is independent of viral replication. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 180:4848-57. [PMID: 18354208 PMCID: PMC4161215 DOI: 10.4049/jimmunol.180.7.4848] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The immune system devotes substantial resources to the lifelong control of persistent pathogens, which were hypothesized to play an important role in immune aging. Specifically, the presence of latent herpesviruses has been correlated with immune exhaustion and shorter lifespan in octogenarians. But neither the causality nor the mechanistic link(s) were established, and the relative roles of persistent antigenic stimulation and of virus-independent homeostatic disturbances in T cell aging remain unresolved. We longitudinally analyzed expansion, contraction, and long-term maintenance of CD8(+) T cells responding to localized infection with a latent virus, HSV-1. Young mice exhibited the expected expansion and contraction of HSV-1-specific cells and the stable maintenance of memory T cells into advanced adulthood. However, upon entry into senescence, many (>40%) animals exhibited an accumulation in Ag-specific cells (memory inflation) which in some animals was comparable to that observed in acute infection. Inflation occurred to the same extent in control mice and mice continuously treated with the anti-HSV drug famciclovir, which inhibits viral replication and was able to reduce expression of the glycoprotein B. Age-related inflation was also found long after infection with an acute virus. The inflating cells largely maintained Ag-specific function, and exhibited typical central memory phenotype, with no signs of Ag-specific activation. They exhibited increased expression of CD122 and CD127, akin to the Ag-independent T cell clonal expansions found in old specific pathogen-free laboratory mice. This collectively suggests that, in this model, the inflating cells may be selected for high responsiveness to environmental cytokines largely in an Ag-independent manner.
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Affiliation(s)
- Anna Lang
- Vaccine and Gene Therapy Institute and the Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97006
| | - James D. Brien
- Vaccine and Gene Therapy Institute and the Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97006
| | - Ilhem Messaoudi
- Vaccine and Gene Therapy Institute and the Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97006
| | - Janko Nikolich-Zugich
- Vaccine and Gene Therapy Institute and the Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97006
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12
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Aldridge BM, Bowen L, Smith BR, Antonelis GA, Gulland F, Stott JL. Paucity of class I MHC gene heterogeneity between individuals in the endangered Hawaiian monk seal population. Immunogenetics 2006; 58:203-15. [PMID: 16528500 DOI: 10.1007/s00251-005-0069-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Accepted: 11/21/2005] [Indexed: 10/24/2022]
Abstract
The Hawaiian monk seal population has experienced precipitous declines in the last 50 years. In this study, we provide evidence that individuals from remaining endangered population exhibit alarming uniformity in class I major histocompatibility (MHC) genes. The peripheral blood leukocyte-derived mRNA of six captive animals rescued from a stranding incident on the French frigate shoals in the Hawaiian archipelago was used to characterize genes in the monk seal class I MHC gene family, from which techniques for genotyping the broader population were designed using degenerate primers designed for the three major established human MHC class I loci (HLA-A, HLA-B, and HLA-C), and by sequencing multiple clones, six unique full-length classical MHC class I gene transcripts were identified among the six animals, three of which were only found in single individuals. Since The low degree of sequence variation between these transcripts and the similarity of genotype between individuals provided preliminary evidence for low class I MHC variability in the population. The sequence information from the class I transcripts from these six animals was used to design several primer sets for examining the extent of MHC variability in the remaining population using a combination of polymerase chain reaction and denaturing gradient gel electrophoresis (DGGE). Several DGGE assays, each one amplifying subtly different class I MHC gene combinations, were designed to compare exons encoding the highly polymorphic domains of the putative peptide-binding region of MHC class I. In combination, these assays failed to show interindividual variability at any of the class I MHC gene loci examined in either the six captive seals or in 80 free-ranging animals ( approximately 6.7% of the estimated population) representing all six major subpopulations of Hawaiian monk seal.
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Affiliation(s)
- Brian M Aldridge
- Veterinary Clinical Sciences, Royal Veterinary College, Hawkshead Lane, North Mymms, Herts, AL97TA, UK.
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13
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Sachdev M, Sankaranarayanan R, Reddanna P, Thangaraj K, Singh L. Major histocompatibility complex class I polymorphism in Asiatic lions. ACTA ACUST UNITED AC 2005; 66:9-18. [PMID: 15982252 DOI: 10.1111/j.1399-0039.2005.00432.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Asiatic lions (Panthera leo persica), whose only natural habitat in the world is the Gir forest sanctuary of Gujarat State in India, are highly endangered and are considered to be highly inbred with narrow genetic diversity. An objective assessment of genetic diversity in their immune loci will help in assessing their survivability and may provide vital clues in designing strategies for their scientific management and conservation. We analyzed the comparative sequence polymorphism at exon 2 and exon 3 of major histocompatibility complex (MHC) class I in three groups of lions, i.e. wild Asiatic (from Gir forest), captive-bred Asiatic (from zoological parks in India), and Afro-Asiatic hybrid groups (from zoological parks in India) through polymorphism chain reaction-assisted sequence-based typing. The two exons were amplified, cloned, sequenced, and analyzed for polymorphism at nucleotide and putative translated product level. The analysis revealed extensive sequence polymorphism not only between clones derived from different lions but also the clones derived from a single lion. Furthermore, the wild Asiatic lions of Gir forest exhibited abundant sequence polymorphism at MHC class I comparable with that of Afro-Asiatic hybrid lions and significantly higher than that of captive-bred Asiatic lions. We hypothesize that Asiatic lions of Gir forest are not highly inbred as thought earlier and they possess abundant sequence polymorphism at MHC class I loci. During this study, 52 new sequences of the multigene MHC class I family were also identified among Asiatic lions.
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Affiliation(s)
- M Sachdev
- Center for Cellular and Molecular Biology, Hyderabad, Andhra Pradesh, India
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14
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Sia C, Weinem M. Genetic susceptibility to type 1 diabetes in the intracellular pathway of antigen processing - a subject review and cross-study comparison. Rev Diabet Stud 2005; 2:40-52. [PMID: 17491658 PMCID: PMC1762495 DOI: 10.1900/rds.2005.2.40] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Ligand binding grooves of MHC class I molecules are able to load a panel of endogenous peptides of varying length and sequence derived from self or foreign origin to activate or deactivate cytotoxic CD8(+) T cells. Peptides are assembled with class I molecules by pathways that are either dependent or independent of transport by ABC proteins (TAP) and degradation in the immunoproteasome by its subunits LMP2 and LMP7. Those peptides that require TAP and LMP treatment appear to be subject to control and optimization by TAP for proper customizing and efficient presentation. Therefore, allelic variations in the coding sequences of TAP and LMP were suspected for a long time to be responsible for improper antigen processing, interruption of self-peptide presentation and reduced cell surface expression of MHC class I molecules resulting in the activation of autoreactive CD8(+) T cells. In this article we reviewed the controversial findings regarding the role of TAP and LMP genes in autoimmune diabetes and reevaluated data of eleven separate studies in a cross-study analysis by genotype and HLA haplotype matching. We could confirm previous results by showing that TAP2*651-A/F and TAP2*687-A/A are significantly associated with disease, independently of linkage disequilibrium (LD). LMP2-R/H surprisingly seems to be primarily disease-conferring although a weak association with DR4 serotypes can be observed. Our analysis also suggests that LMP7-B/B, TAP1-A/A and TAP2*687-A/B are the protective genotypes and that these associations are not secondary to LD with DRB1. Consequently, intracellular antigen processing associated with TAP- and proteasome-dependent pathways seems to be a critical element in T cell selection for the retention of a balanced immunity.
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Affiliation(s)
- Charles Sia
- Department of Immunology, United Biomedical Inc., 25 Davids Drive, Hauppage, New York 11788, USA.
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15
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Tynan FE, Borg NA, Miles JJ, Beddoe T, El-Hassen D, Silins SL, van Zuylen WJM, Purcell AW, Kjer-Nielsen L, McCluskey J, Burrows SR, Rossjohn J. High resolution structures of highly bulged viral epitopes bound to major histocompatibility complex class I. Implications for T-cell receptor engagement and T-cell immunodominance. J Biol Chem 2005; 280:23900-9. [PMID: 15849183 DOI: 10.1074/jbc.m503060200] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although HLA class I alleles can bind epitopes up to 14 amino acids in length, little is known about the immunogenicity or the responding T-cell repertoire against such determinants. Here, we describe an HLA-B*3508-restricted cytotoxic T lymphocyte response to a 13-mer viral epitope (LPEPLPQGQLTAY). The rigid, centrally bulged epitope generated a biased T-cell response. Only the N-terminal face of the peptide bulge was critical for recognition by the dominant clonotype SB27. The SB27 public T-cell receptor (TcR) associated slowly onto the complex between the bulged peptide and the major histocompatibility complex, suggesting significant remodeling upon engagement. The broad antigen-binding cleft of HLA-B*3508 represents a critical feature for engagement of the public TcR, as the narrower binding cleft of HLA-B*3501(LPEPLPQGQLTAY), which differs from HLA-B*3508 by a single amino acid polymorphism (Arg156 --> Leu), interacted poorly with the dominant TcR. Biased TcR usage in this cytotoxic T lymphocyte response appears to reflect a dominant role of the prominent peptide x major histocompatibility complex class I surface.
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Affiliation(s)
- Fleur E Tynan
- Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia
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16
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Block MS, Mendez-Fernandez YV, Van Keulen VP, Hansen MJ, Allen KS, Taboas AL, Rodriguez M, Pease LR. Inability of bm14 mice to respond to Theiler's murine encephalomyelitis virus is caused by defective antigen presentation, not repertoire selection. THE JOURNAL OF IMMUNOLOGY 2005; 174:2756-62. [PMID: 15728484 DOI: 10.4049/jimmunol.174.5.2756] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Natural selection drives diversification of MHC class I proteins, but the mechanism by which selection for polymorphism occurs is not known. New variant class I alleles differ from parental alleles both in the nature of the CD8 T cell repertoire formed and the ability to present pathogen-derived peptides. In the current study, we examined whether T cell repertoire differences, Ag presentation differences, or both account for differential viral resistance between mice bearing variant and parental alleles. We demonstrate that nonresponsive mice have inadequate presentation of viral Ag, but have T cell repertoires capable of mounting Ag-specific responses. Although previous work suggests a correlation between the ability to present an Ag and the ability to generate a repertoire responsive to that Ag, we show that the two functions of MHC class I are independent.
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Affiliation(s)
- Matthew S Block
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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17
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Miley MJ, Messaoudi I, Metzner BM, Wu Y, Nikolich-Zugich J, Fremont DH. Structural basis for the restoration of TCR recognition of an MHC allelic variant by peptide secondary anchor substitution. ACTA ACUST UNITED AC 2004; 200:1445-54. [PMID: 15557346 PMCID: PMC2211956 DOI: 10.1084/jem.20040217] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Major histocompatibility complex (MHC) class I variants H-2Kb and H-2Kbm8 differ primarily in the B pocket of the peptide-binding groove, which serves to sequester the P2 secondary anchor residue. This polymorphism determines resistance to lethal herpes simplex virus (HSV-1) infection by modulating T cell responses to the immunodominant glycoprotein B498-505 epitope, HSV8. We studied the molecular basis of these effects and confirmed that T cell receptors raised against Kb–HSV8 cannot recognize H-2Kbm8–HSV8. However, substitution of SerP2 to GluP2 (peptide H2E) reversed T cell receptor (TCR) recognition; H-2Kbm8–H2E was recognized whereas H-2Kb–H2E was not. Insight into the structural basis of this discrimination was obtained by determining the crystal structures of all four MHC class I molecules in complex with bound peptide (pMHCs). Surprisingly, we find no concerted pMHC surface differences that can explain the differential TCR recognition. However, a correlation is apparent between the recognition data and the underlying peptide-binding groove chemistry of the B pocket, revealing that secondary anchor residues can profoundly affect TCR engagement through mechanisms distinct from the alteration of the resting state conformation of the pMHC surface.
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Affiliation(s)
- Michael J Miley
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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18
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Nikolich-Zugich J, Slifka MK, Messaoudi I. The many important facets of T-cell repertoire diversity. Nat Rev Immunol 2004; 4:123-32. [PMID: 15040585 DOI: 10.1038/nri1292] [Citation(s) in RCA: 450] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the thymus, a diverse and polymorphic T-cell repertoire is generated by random recombination of discrete T-cell receptor (TCR)-alphabeta gene segments. This repertoire is then shaped by intrathymic selection events to generate a peripheral T-cell pool of self-MHC restricted, non-autoaggressive T cells. It has long been postulated that some optimal level of TCR diversity allows efficient protection against pathogens. This article focuses on several recent advances that address the required diversity for the generation of an optimal immune response.
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Affiliation(s)
- Janko Nikolich-Zugich
- Vaccine and Gene Therapy Institute, Department of Molecular Microbiology and Immunology and the Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon 97006, USA.
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19
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Block MS, Hansen MJ, Van Keulen VP, Pease LR. MHC class I gene conversion mutations alter the CD8 T cell repertoire. THE JOURNAL OF IMMUNOLOGY 2004; 171:4006-10. [PMID: 14530320 DOI: 10.4049/jimmunol.171.8.4006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
MHC class I molecules are highly polymorphic within populations. This diversity is thought to be the result of selective maintenance of new class I alleles formed by gene conversion. It has been proposed that rare alleles are maintained by their ability to confer resistance to common pathogens. Investigation has focused on differences in the presentation of foreign Ags by class I alleles, but the majority of peptides presented by class I molecules are self peptides used in shaping the naive T cell repertoire. We propose that the key substrate for the natural selection of class I gene conversion variants is the diversity in immune potential formed by new alleles. We show that T cells compete with each other for niches in the thymus and spleen during development, and that competition between different clones is dramatically affected by class I mutations. We also show that peripheral naive T cells proliferate preferentially in the presence of the class I variant that directed T cell development. The data argue that class I gene conversion mutations dramatically affect both the development and the maintenance of the naive CD8 T cell repertoire.
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Affiliation(s)
- Matthew S Block
- Department of Immunology, Mayo Medical and Graduate Schools, Mayo Clinic Rochester, Rochester, MN 55905, USA
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20
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Macdonald WA, Purcell AW, Mifsud NA, Ely LK, Williams DS, Chang L, Gorman JJ, Clements CS, Kjer-Nielsen L, Koelle DM, Burrows SR, Tait BD, Holdsworth R, Brooks AG, Lovrecz GO, Lu L, Rossjohn J, McCluskey J. A naturally selected dimorphism within the HLA-B44 supertype alters class I structure, peptide repertoire, and T cell recognition. J Exp Med 2003; 198:679-91. [PMID: 12939341 PMCID: PMC2194191 DOI: 10.1084/jem.20030066] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2003] [Revised: 06/10/2003] [Accepted: 06/10/2003] [Indexed: 11/04/2022] Open
Abstract
HLA-B*4402 and B*4403 are naturally occurring MHC class I alleles that are both found at a high frequency in all human populations, and yet they only differ by one residue on the alpha2 helix (B*4402 Asp156-->B*4403 Leu156). CTLs discriminate between HLA-B*4402 and B*4403, and these allotypes stimulate strong mutual allogeneic responses reflecting their known barrier to hemopoeitic stem cell transplantation. Although HLA-B*4402 and B*4403 share >95% of their peptide repertoire, B*4403 presents more unique peptides than B*4402, consistent with the stronger T cell alloreactivity observed toward B*4403 compared with B*4402. Crystal structures of B*4402 and B*4403 show how the polymorphism at position 156 is completely buried and yet alters both the peptide and the heavy chain conformation, relaxing ligand selection by B*4403 compared with B*4402. Thus, the polymorphism between HLA-B*4402 and B*4403 modifies both peptide repertoire and T cell recognition, and is reflected in the paradoxically powerful alloreactivity that occurs across this "minimal" mismatch. The findings suggest that these closely related class I genes are maintained in diverse human populations through their differential impact on the selection of peptide ligands and the T cell repertoire.
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Affiliation(s)
- Whitney A Macdonald
- Dept. of Microbiology and Immunology, The University of Melbourne, Parkville, Victoria 3010, Australia
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21
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Aeschlimann PB, Häberli MA, Reusch TBH, Boehm T, Milinski M. Female sticklebacks Gasterosteus aculeatus use self-reference to optimize MHC allele number during mate selection. Behav Ecol Sociobiol 2003. [DOI: 10.1007/s00265-003-0611-6] [Citation(s) in RCA: 168] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Messaoudi I, Guevara Patiño JA, Dyall R, LeMaoult J, Nikolich-Zugich J. Direct link between mhc polymorphism, T cell avidity, and diversity in immune defense. Science 2002; 298:1797-800. [PMID: 12459592 DOI: 10.1126/science.1076064] [Citation(s) in RCA: 247] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Major histocompatibility complex (mhc)-encoded molecules govern immune responses by presenting antigenic peptides to T cells. The extensive polymorphism of genes encoding these molecules is believed to enhance immune defense by broadening the array of antigenic peptides available for T cell recognition, but direct evidence supporting the importance of this mechanism in combating pathogens is limited. Here we link mhc polymorphism-driven diversification of the cytotoxic T lymphocyte (CTL) repertoire to the generation of high-avidity, protective antiviral T cells and to superior antiviral defense. Thus, much of the beneficial effect of the mhc polymorphism in immune defense may be due to its critical influence on the properties of the selected CTL repertoire.
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MESH Headings
- Adoptive Transfer
- Animals
- Complementarity Determining Regions
- Cytotoxicity, Immunologic
- Female
- Genes, MHC Class I
- H-2 Antigens/genetics
- H-2 Antigens/immunology
- Herpes Simplex/immunology
- Herpesvirus 1, Human/immunology
- Immunity, Innate
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred Strains
- Polymorphism, Genetic
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- T-Lymphocytes, Cytotoxic/immunology
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Affiliation(s)
- Ilhem Messaoudi
- Vaccine and Gene Therapy Institute and the Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
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Penn DJ, Damjanovich K, Potts WK. MHC heterozygosity confers a selective advantage against multiple-strain infections. Proc Natl Acad Sci U S A 2002; 99:11260-4. [PMID: 12177415 PMCID: PMC123244 DOI: 10.1073/pnas.162006499] [Citation(s) in RCA: 418] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2002] [Indexed: 11/18/2022] Open
Abstract
Genetic heterozygosity is thought to enhance resistance of hosts to infectious diseases, but few tests of this idea exist. In particular, heterozygosity at the MHC, the highly polymorphic loci that control immunological recognition of pathogens, is suspected to confer a selective advantage by enhancing resistance to infectious diseases (the "heterozygote advantage" hypothesis). To test this hypothesis, we released mice into large population enclosures and challenged them with multiple strains of Salmonella and one of Listeria. We found that during Salmonella infections with three avirulent strains, MHC heterozygotes had greater survival and weight than homozygotes (unlike sham controls), and they were more likely to clear chronic Salmonella infection than homozygotes. In laboratory experiments, we found that MHC heterozygosity enhanced the clearance of multiple-strain Salmonella infections. Yet, contrary to what is widely assumed, the benefits of heterozygosity were due to resistance being dominant rather than overdominant, i.e., heterozygotes were more resistant than the average of parental homozygotes, but they were not more resistant than both. The fact that MHC heterozygotes were more resistant to infection and had higher fitness than homozygotes provides a functional explanation for MHC-disassortative mating preferences.
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Affiliation(s)
- Dustin J Penn
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA
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24
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Messaoudi I, LeMaoult J, Metzner BM, Miley MJ, Fremont DH, Nikolich-Zugich J. Functional evidence that conserved TCR CDR alpha 3 loop docking governs the cross-recognition of closely related peptide:class I complexes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:836-43. [PMID: 11441090 DOI: 10.4049/jimmunol.167.2.836] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The TCR recognizes its peptide:MHC (pMHC) ligand by assuming a diagonal orientation relative to the MHC helices, but it is unclear whether and to what degree individual TCRs exhibit docking variations when contacting similar pMHC complexes. We analyzed monospecific and cross-reactive recognition by diverse TCRs of an immunodominant HVH-1 glycoprotein B epitope (HSV-8p) bound to two closely related MHC class I molecules, H-2K(b) and H-2K(bm8). Previous studies indicated that the pMHC portion likely to vary in conformation between the two complexes resided at the N-terminal part of the complex, adjacent to peptide residues 2-4 and the neighboring MHC side chains. We found that CTL clones sharing TCR beta-chains exhibited disparate recognition patterns, whereas those with drastically different TCRbeta-chains but sharing identical TCRalpha CDR3 loops displayed identical functional specificity. This suggested that the CDRalpha3 loop determines the TCR specificity in our model, the conclusion supported by modeling of the TCR over the actual HSV-8:K(b) crystal structure. Importantly, these results indicate a remarkable conservation in CDRalpha3 positioning, and, therefore, in docking of diverse TCRalphabeta heterodimers onto variant peptide:class I complexes, implying a high degree of determinism in thymic selection and T cell activation.
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MESH Headings
- Amino Acid Sequence
- Animals
- Cell Line
- Clone Cells
- Conserved Sequence/genetics
- Conserved Sequence/immunology
- Crystallization
- Crystallography, X-Ray
- Epitopes, T-Lymphocyte/genetics
- Epitopes, T-Lymphocyte/metabolism
- H-2 Antigens/genetics
- H-2 Antigens/metabolism
- Herpesvirus 1, Human/immunology
- Immunodominant Epitopes/genetics
- Immunodominant Epitopes/metabolism
- Lymphocyte Activation/genetics
- Mice
- Mice, Inbred C57BL
- Models, Molecular
- Molecular Sequence Data
- Peptide Fragments/genetics
- Peptide Fragments/immunology
- Peptide Fragments/metabolism
- Protein Structure, Secondary/genetics
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
- Viral Envelope Proteins/immunology
- Viral Envelope Proteins/metabolism
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Affiliation(s)
- I Messaoudi
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
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