151
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Cole DK, Yuan F, Rizkallah PJ, Miles JJ, Gostick E, Price DA, Gao GF, Jakobsen BK, Sewell AK. Germ line-governed recognition of a cancer epitope by an immunodominant human T-cell receptor. J Biol Chem 2009; 284:27281-9. [PMID: 19605354 PMCID: PMC2785656 DOI: 10.1074/jbc.m109.022509] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 05/18/2009] [Indexed: 11/06/2022] Open
Abstract
CD8(+) T-cells specific for MART-1-(26-35), a dominant melanoma epitope restricted by human leukocyte antigen (HLA)-A*0201, are exceptionally common in the naive T-cell repertoire. Remarkably, the TRAV12-2 gene is used to encode the T-cell receptor alpha (TCRalpha) chain in >87% of these T-cells. Here, the molecular basis for this genetic bias is revealed from the structural and thermodynamic properties of an archetypal TRAV12-2-encoded TCR complexed to the clinically relevant heteroclitic peptide, ELAGIGILTV, bound to HLA-A*0201 (A2-ELA). Unusually, the TRAV12-2 germ line-encoded regions of the TCR dominate the major atomic contacts with the peptide at the TCR/A2-ELA interface. This "innate" pattern of antigen recognition probably explains the unique characteristics and extraordinary frequencies of CD8(+) T-cell responses to this epitope.
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Affiliation(s)
- David K. Cole
- From the Department of Infection, Immunity, and Biochemistry, Henry Wellcome Building, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, United Kingdom
| | - Fang Yuan
- the Nuffield Department of Clinical Medicine, John Radcliffe Hospital, Oxford University, Oxford OX3 9DU, United Kingdom
| | - Pierre J. Rizkallah
- From the Department of Infection, Immunity, and Biochemistry, Henry Wellcome Building, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, United Kingdom
- the STFC Daresbury Laboratory, Warrington, Cheshire WA4 4AD, United Kingdom
| | - John J. Miles
- From the Department of Infection, Immunity, and Biochemistry, Henry Wellcome Building, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, United Kingdom
- the Cellular Immunology Laboratory, Queensland Institute of Medical Research, University of Queensland, Brisbane 4029, Australia
| | - Emma Gostick
- From the Department of Infection, Immunity, and Biochemistry, Henry Wellcome Building, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, United Kingdom
| | - David A. Price
- From the Department of Infection, Immunity, and Biochemistry, Henry Wellcome Building, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, United Kingdom
| | - George F. Gao
- the **Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China, and
| | - Bent K. Jakobsen
- Immunocore Limited, 57C Milton Park, Abingdon, Oxon OX14 4RX, United Kingdom
| | - Andrew K. Sewell
- From the Department of Infection, Immunity, and Biochemistry, Henry Wellcome Building, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, United Kingdom
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152
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Horlock C, Stott B, Dyson J, Ogg G, McPherson T, Jones L, Sewell AK, Wooldridge L, Cole DK, Stebbing J, Savage P. ELISPOT and functional T cell analyses using HLA mono-specific target cells. J Immunol Methods 2009; 350:150-60. [DOI: 10.1016/j.jim.2009.08.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 08/14/2009] [Accepted: 08/18/2009] [Indexed: 10/20/2022]
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153
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van Heijst JWJ, Gerlach C, Swart E, Sie D, Nunes-Alves C, Kerkhoven RM, Arens R, Correia-Neves M, Schepers K, Schumacher TNM. Recruitment of Antigen-Specific CD8+ T Cells in Response to Infection Is Markedly Efficient. Science 2009; 325:1265-9. [DOI: 10.1126/science.1175455] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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154
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Stone JD, Chervin AS, Kranz DM. T-cell receptor binding affinities and kinetics: impact on T-cell activity and specificity. Immunology 2009; 126:165-76. [PMID: 19125887 DOI: 10.1111/j.1365-2567.2008.03015.x] [Citation(s) in RCA: 266] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The interaction between the T-cell receptor (TCR) and its peptide-major histocompatibility complex (pepMHC) ligand plays a critical role in determining the activity and specificity of the T cell. The binding properties associated with these interactions have now been studied in many systems, providing a framework for a mechanistic understanding of the initial events that govern T-cell function. There have been various other reviews that have described the structural and biochemical features of TCR : pepMHC interactions. Here we provide an overview of four areas that directly impact our understanding of T-cell function, as viewed from the perspective of the TCR : pepMHC interaction: (1) relationships between T-cell activity and TCR : pepMHC binding parameters, (2) TCR affinity, avidity and clustering, (3) influence of coreceptors on pepMHC binding by TCRs and T-cell activity, and (4) impact of TCR binding affinity on antigenic peptide specificity.
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Affiliation(s)
- Jennifer D Stone
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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155
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Haidar JN, Pierce B, Yu Y, Tong W, Li M, Weng Z. Structure-based design of a T-cell receptor leads to nearly 100-fold improvement in binding affinity for pepMHC. Proteins 2009; 74:948-60. [PMID: 18767161 DOI: 10.1002/prot.22203] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
T-cell receptors (TCRs) are proteins that recognize peptides from foreign proteins bound to the major histocompatibility complex (MHC) on the surface of an antigen-presenting cell. This interaction enables the T cells to initiate a cell-mediated immune response to terminate cells displaying the foreign peptide on their MHC. Naturally occurring TCRs have high specificity but low affinity toward the peptide-MHC (pepMHC) complex. This prevents the usage of solubilized TCRs for diagnosis and treatment of viral infections or cancers. Efforts to enhance the binding affinity of several TCRs have been reported in recent years, through randomized libraries and in vitro selection. However, there have been no reported efforts to enhance the affinity via structure-based design, which allows more control and understanding of the mechanism of improvement. Here, we have applied structure-based design to a human TCR to improve its pepMHC binding. Our design method evolved based on iterative steps of prediction, testing, and generating more predictions based on the new data. The final design function, named ZAFFI, has a correlation of 0.77 and average error of 0.35 kcal/mol with the binding free energies of 26 point mutations for this system that we measured by surface plasmon resonance (SPR). Applying the filter that we developed to remove nonbinding predictions, this correlation increases to 0.85, and the average error decreases to 0.3 kcal/mol. Using this algorithm, we predicted and tested several point mutations that improved binding, with one giving over sixfold binding improvement. Four of the point mutations that improved binding were then combined to give a mutant TCR that binds the pepMHC 99 times more strongly than the wild-type TCR.
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Affiliation(s)
- Jaafar N Haidar
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, USA
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156
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Wooldridge L, Lissina A, Cole DK, van den Berg HA, Price DA, Sewell AK. Tricks with tetramers: how to get the most from multimeric peptide-MHC. Immunology 2009; 126:147-64. [PMID: 19125886 PMCID: PMC2632693 DOI: 10.1111/j.1365-2567.2008.02848.x] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Revised: 03/18/2008] [Accepted: 03/18/2008] [Indexed: 01/16/2023] Open
Abstract
The development of fluorochrome-conjugated peptide-major histocompatibility complex (pMHC) multimers in conjunction with continuing advances in flow cytometry has transformed the study of antigen-specific T cells by enabling their visualization, enumeration, phenotypic characterization and isolation from ex vivo samples. Here, we bring together and discuss some of the 'tricks' that can be used to get the most out of pMHC multimers. These include: (1) simple procedures that can substantially enhance the staining intensity of cognate T cells with pMHC multimers; (2) the use of pMHC multimers to stain T cells with very-low-affinity T-cell receptor (TCR)/pMHC interactions, such as those that typically predominate in tumour-specific responses; and (3) the physical grading and clonotypic dissection of antigen-specific T cells based on the affinity of their cognate TCR using mutant pMHC multimers in conjunction with new approaches to the molecular analysis of TCR gene expression. We also examine how soluble pMHC can be used to examine T-cell activation, manipulate T-cell responses and study allogeneic and superantigen interactions with TCRs. Finally, we discuss the problems that arise with pMHC class II (pMHCII) multimers because of the low affinity of TCR/pMHCII interactions and lack of 'coreceptor help'.
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Affiliation(s)
- Linda Wooldridge
- Department of Medical Biochemistry and Immunology, Cardiff University School of Medicine, Henry Wellcome Building, Heath Park, Cardiff, UK
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157
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Chattopadhyay PK, Melenhorst JJ, Ladell K, Gostick E, Scheinberg P, Barrett AJ, Wooldridge L, Roederer M, Sewell AK, Price DA. Techniques to improve the direct ex vivo detection of low frequency antigen-specific CD8+ T cells with peptide-major histocompatibility complex class I tetramers. Cytometry A 2008; 73:1001-9. [PMID: 18836993 DOI: 10.1002/cyto.a.20642] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The ability to quantify and characterize antigen-specific CD8+ T cells irrespective of functional readouts using fluorochrome-conjugated peptide-major histocompatibility complex class I (pMHCI) tetramers in conjunction with flow cytometry has transformed our understanding of cellular immune responses over the past decade. In the case of prevalent CD8+ T cell populations that engage cognate pMHCI tetramers with high avidities, direct ex vivo identification and subsequent data interpretation is relatively straightforward. However, the accurate identification of low frequency antigen-specific CD8+ T cell populations can be complicated, especially in situations where T cell receptor-mediated tetramer binding occurs at low avidities. Here, we highlight a few simple techniques that can be employed to improve the visual resolution, and hence the accurate quantification, of tetramer binding CD8+ T cell populations by flow cytometry. These methodological modifications enhance signal intensity, especially in the case of specific CD8+ T cell populations that bind cognate antigen with low avidities, minimize background noise, and enable improved discrimination of true pMHCI tetramer binding events from nonspecific uptake.
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Affiliation(s)
- Pratip K Chattopadhyay
- Immunotechnology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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158
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Varela-Rohena A, Molloy PE, Dunn SM, Li Y, Suhoski MM, Carroll RG, Milicic A, Mahon T, Sutton DH, Laugel B, Moysey R, Cameron BJ, Vuidepot A, Purbhoo MA, Cole DK, Phillips RE, June CH, Jakobsen BK, Sewell AK, Riley JL. Control of HIV-1 immune escape by CD8 T cells expressing enhanced T-cell receptor. Nat Med 2008; 14:1390-5. [PMID: 18997777 DOI: 10.1038/nm.1779] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Accepted: 04/28/2008] [Indexed: 11/09/2022]
Abstract
HIV's considerable capacity to vary its HLA-I-restricted peptide antigens allows it to escape from host cytotoxic T lymphocytes (CTLs). Nevertheless, therapeutics able to target HLA-I-associated antigens, with specificity for the spectrum of preferred CTL escape mutants, could prove effective. Here we use phage display to isolate and enhance a T-cell antigen receptor (TCR) originating from a CTL line derived from an infected person and specific for the immunodominant HLA-A(*)02-restricted, HIVgag-specific peptide SLYNTVATL (SL9). High-affinity (K(D) < 400 pM) TCRs were produced that bound with a half-life in excess of 2.5 h, retained specificity, targeted HIV-infected cells and recognized all common escape variants of this epitope. CD8 T cells transduced with this supraphysiologic TCR produced a greater range of soluble factors and more interleukin-2 than those transduced with natural SL9-specific TCR, and they effectively controlled wild-type and mutant strains of HIV at effector-to-target ratios that could be achieved by T-cell therapy.
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Affiliation(s)
- Angel Varela-Rohena
- Department of Pathology and Laboratory Medicine, Abramson Family Cancer Research Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6160, USA
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159
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High avidity myeloid leukemia-associated antigen-specific CD8+ T cells preferentially reside in the bone marrow. Blood 2008; 113:2238-44. [PMID: 18997173 DOI: 10.1182/blood-2008-04-151969] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The activity of allogeneic CD8(+) T cells specific for leukemia-associated antigens (LAAs) is thought to mediate, at least in part, the curative effects of hematopoietic stem cell transplantation (HSCT) in myeloid malignancies. However, the identity and nature of clinically relevant LAA-specific CD8(+) T-cell populations have proven difficult to define. Here, we used a combination of coreceptor-mutated peptide-major histocompatibility complex class I (pMHCI) tetramers and polychromatic flow cytometry to examine the avidity profiles, phenotypic characteristics, and anatomical distribution of HLA A*0201-restricted CD8(+) T-cell populations specific for LAAs that are over-expressed in myeloid leukemias. Remarkably, LAA-specific CD8(+) T-cell populations, regardless of fine specificity, were confined almost exclusively to the bone marrow; in contrast, CD8(+) T-cell populations specific for the HLA A*0201-restricted cytomegalovirus (CMV) pp65(495-503) epitope were phenotypically distinct and evenly distributed between bone marrow and peripheral blood. Furthermore, bone marrow-resident LAA-specific CD8(+) T cells frequently engaged cognate antigen with high avidity; notably, this was the case in all tested bone marrow samples derived from patients who achieved clinical remission after HSCT. These data suggest that concomitant examination of bone marrow specimens in patients with myeloid leukemias might yield more definitive information in the search for immunologic prognosticators of clinical outcome.
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160
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Rich RL, Myszka DG. Survey of the year 2007 commercial optical biosensor literature. J Mol Recognit 2008; 21:355-400. [DOI: 10.1002/jmr.928] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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161
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Protein kinase inhibitors substantially improve the physical detection of T-cells with peptide-MHC tetramers. J Immunol Methods 2008; 340:11-24. [PMID: 18929568 PMCID: PMC3052435 DOI: 10.1016/j.jim.2008.09.014] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 09/09/2008] [Accepted: 09/11/2008] [Indexed: 11/21/2022]
Abstract
Flow cytometry with fluorochrome-conjugated peptide-major histocompatibility complex (pMHC) tetramers has transformed the study of antigen-specific T-cells by enabling their visualization, enumeration, phenotypic characterization and isolation from ex vivo samples. Here, we demonstrate that the reversible protein kinase inhibitor (PKI) dasatinib improves the staining intensity of human (CD8+ and CD4+) and murine T-cells without concomitant increases in background staining. Dasatinib enhances the capture of cognate pMHC tetramers from solution and produces higher intensity staining at lower pMHC concentrations. Furthermore, dasatinib reduces pMHC tetramer-induced cell death and substantially lowers the T-cell receptor (TCR)/pMHC interaction affinity threshold required for cell staining. Accordingly, dasatinib permits the identification of T-cells with very low affinity TCR/pMHC interactions, such as those that typically predominate in tumour-specific responses and autoimmune conditions that are not amenable to detection by current technology.
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162
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Melenhorst JJ, Scheinberg P, Chattopadhyay PK, Lissina A, Gostick E, Cole DK, Wooldridge L, van den Berg HA, Bornstein E, Hensel NF, Douek DC, Roederer M, Sewell AK, Barrett AJ, Price DA. Detection of low avidity CD8(+) T cell populations with coreceptor-enhanced peptide-major histocompatibility complex class I tetramers. J Immunol Methods 2008; 338:31-9. [PMID: 18675271 PMCID: PMC2714739 DOI: 10.1016/j.jim.2008.07.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2008] [Revised: 05/08/2008] [Accepted: 07/01/2008] [Indexed: 10/21/2022]
Abstract
The development of soluble recombinant peptide-major histocompatibility complex class I (pMHCI) molecules conjugated in multimeric form to fluorescent labels has enabled the physical quantification and characterization of antigen-specific CD8(+) T cell populations by flow cytometry. Several factors determine the binding threshold that enables visualization of cognate CD8(+) T cells with these reagents; these include the affinity of the T cell receptor (TCR) for pMHCI antigen. Here, we show that multimers constructed from peptide-human leukocyte antigen (pHLA) A0201 monomers engineered in the heavy chain alpha2 domain to enhance CD8 binding (K(D) approximately 85 microM) without impacting the TCR binding platform can detect cognate CD8(+) T cells bearing low affinity TCRs that are not visible with the corresponding wildtype pHLA A0201 multimeric complexes. Mechanistically, this effect is mediated by a disproportionate enhancement of the TCR/pMHCI association rate. In direct ex vivo applications, these coreceptor-enhanced multimers exhibit faithful cognate binding properties; concomitant increases in background staining within the non-cognate CD8(+) T cell population can be resolved phenotypically using polychromatic flow cytometry as a mixture of naïve and memory cells. These findings provide the first validation of a novel approach to the physical detection of low avidity antigen-specific CD8(+) T cell populations; such coreceptor-enhanced multimeric reagents are likely to be useful in a multitude of settings for the detection of auto-immune, tumor-specific and cross-reactive CD8(+) T cells.
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Affiliation(s)
- J. Joseph Melenhorst
- Hematology Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Phillip Scheinberg
- Hematology Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Human Immunology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Pratip K. Chattopadhyay
- Immunotechnology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anna Lissina
- Department of Medical Biochemistry and Immunology, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Emma Gostick
- Department of Medical Biochemistry and Immunology, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - David K. Cole
- Department of Medical Biochemistry and Immunology, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Linda Wooldridge
- Department of Medical Biochemistry and Immunology, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | | | - Ethan Bornstein
- Human Immunology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nancy F. Hensel
- Hematology Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Daniel C. Douek
- Human Immunology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mario Roederer
- Immunotechnology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrew K. Sewell
- Department of Medical Biochemistry and Immunology, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - A. John Barrett
- Hematology Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David A. Price
- Human Immunology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Medical Biochemistry and Immunology, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
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163
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Riddle DS, Miller PJ, Vincent BG, Kepler TB, Maile R, Frelinger JA, Collins EJ. Rescue of cytotoxic function in the CD8alpha knockout mouse by removal of MHC class II. Eur J Immunol 2008; 38:1511-21. [PMID: 18465769 DOI: 10.1002/eji.200737710] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CD8 plays an important role in the activity of cytolytic T cells (CTL). However, whether or not CD8 is required for the development of CTL has not been clearly determined. Cytotoxic activity in the CD8alpha knockout mouse is difficult to induce, and has only been demonstrated against allogenic MHC targets. The lack of cytotoxicity may result from impaired lineage commitment of CTL in the absence of CD8, or diminished competitiveness during selection against (unimpaired) development of CD4(+) T cells on MHC class II (MHC II). To differentiate between these possibilities, we have generated a double-knockout mouse (MHC II(-/-)CD8alpha(-/-)). In MHC II(-/-)CD8alpha(-/-) mice, developing MHC class I (MHC I)-reactive thymocytes cannot rely upon CD8 for selection, but they also cannot be overwhelmed by efficient selection of MHC II-reactive thymocytes. In this mouse, a large, heterogeneous population of peripheral coreceptor double-negative (DN) and CD4(+) T cells develops. Peripheral DN T cells are fully functional CTL. They display cytolytic activity against allogeneic MHC, and against syngeneic MHC following lymphocytic choriomeningitis virus (LCMV) infection. Cells from LCMV-infected mice bind more MHC I tetramer at lower concentrations than their wild-type CTL counterparts. These results demonstrate unequivocally that CD8 is not required for commitment of thymocytes to the CTL lineage.
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Affiliation(s)
- David S Riddle
- University of North Carolina at Chapel Hill, Department of Microbiology and Immunology, Chapel Hill, NC 27599-7290, USA
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164
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Vollers SS, Stern LJ. Class II major histocompatibility complex tetramer staining: progress, problems, and prospects. Immunology 2008; 123:305-13. [PMID: 18251991 DOI: 10.1111/j.1365-2567.2007.02801.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The use of major histocompatibility complex (MHC) tetramers in the detection and analysis of antigen-specific T cells has become more widespread since its introduction 11 years ago. Early challenges in the application of tetramer staining to CD4+ T cells centred around difficulties in the expression of various class II MHC allelic variants and the detection of low-frequency T cells in mixed populations. As many of the technical obstacles to class II MHC tetramer staining have been overcome, the focus has returned to uncertainties concerning how oligomer valency and T-cell receptor/MHC affinity affect tetramer binding. Such issues have become more important with an increase in the number of studies relying on direct ex vivo analysis of antigen-specific CD4+ T cells. In this review we discuss which problems in class II MHC tetramer staining have been solved to date, and which matters remain to be considered.
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Affiliation(s)
- Sabrina S Vollers
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
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165
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Ohlson S. Designing transient binding drugs: a new concept for drug discovery. Drug Discov Today 2008; 13:433-9. [PMID: 18468561 DOI: 10.1016/j.drudis.2008.02.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2007] [Revised: 01/27/2008] [Accepted: 02/01/2008] [Indexed: 10/22/2022]
Abstract
A multitude of weak, or transient, biological interactions (dissociation constant: K(d)>microM), either working alone or in concert, occur frequently throughout biological systems. We are starting to appreciate their importance in complex biological networks. This realization has important implications to drug discovery as we can question the current paradigm of drug design to find the highest possible binders (drugs) to a given target (receptor). Development of transient drugs, defined by their binding to target, can be based on high-off-rates, multivalent approaches or multiple targets. Now, techniques are available to discover such drug candidates. The greatest problem yet to overcome is probably the mind-set of the individual researcher that weak binders are undesired and therefore of no benefit.
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Affiliation(s)
- Sten Ohlson
- School of Pure and Applied Natural Sciences, University of Kalmar, Kalmar, Sweden.
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166
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Cole DK, Dunn SM, Sami M, Boulter JM, Jakobsen BK, Sewell AK. T cell receptor engagement of peptide-major histocompatibility complex class I does not modify CD8 binding. Mol Immunol 2008; 45:2700-9. [PMID: 18243322 DOI: 10.1016/j.molimm.2007.12.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Accepted: 12/14/2007] [Indexed: 11/30/2022]
Abstract
Activation of cytotoxic T cells is initiated by engagement of the T-cell receptor (TCR) with peptide-major histocompatibility class I complexes (pMHCI). The CD8 co-receptor also binds to pMHCI, but at a distinct site, and allows the potential for tripartite TCR/pMHCI/CD8 interactions, which can increase T cell antigen sensitivity. There has been a substantial interest in the effect of the pMHCI/CD8 interaction upon TCR/pMHCI engagement, and several conflicting studies have examined this event, using the soluble extracellular domains of CD8 and the TCR, by surface plasmon resonance. However, the evidence to date suggests that the TCR engages cognate pMHCI before CD8 recruitment, so the question of whether TCR engagement alters CD8 binding is likely to be more relevant to the biological order of T cell antigen encounter. Here, we have examined the binding of CD8 to several variants of the HLA A2-restricted telomerase(540-548) antigen (ILAKFLHWL) and the HLA A2-restricted NY-ESO-1(157-165) antigen (SLLMWITQC) that bind to their cognate TCRs with distinct affinities and kinetics. These interactions represent a range of agonists that exhibit different CD8 dependency for activation of their respective T cells. By using engineered affinity enhanced TCRs to these ligands, which have extended off-rates of approximately 1h compared to seconds for the wildtype TCRs, we have examined pMHCI/CD8 binding before and during TCR-engagement. Here we show that the binding of the extracellular domain of the TCR to pMHCI does not transmit structural changes to the pMHCI-CD8 binding site that would alter the subsequent pMHCI/CD8 interaction.
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Affiliation(s)
- David K Cole
- Department of Medical Biochemistry & Immunology, Cardiff University, School of Medicine, Heath Park, Cardiff, CF14 4XN, UK.
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