26 results on '"Bulek, Anna"'
Search Results
2. HLA A*24:02–restricted T cell receptors cross-recognize bacterial and preproinsulin peptides in type 1 diabetes.
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Dolton, Garry, Bulek, Anna, Wall, Aaron, Thomas, Hannah, Hopkins, Jade R., Rius, Cristina, Galloway, Sarah A. E., Whalley, Thomas, Tan, Li Rong, Morin, Théo, Omidvar, Nader, Fuller, Anna, Topley, Katie, Hasan, Md Samiul, Jain, Shikha, D’Souza, Nirupa, Hodges-Hoyland, Thomas, Spiller, Owen B., Kronenberg-Versteeg, Deborah, and Szomolay, Barbara
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TYPE 1 diabetes , *T cell receptors , *MOLECULAR mimicry , *PEPTIDES , *AMINO acid sequence , *T cells - Abstract
CD8+ T cells destroy insulin-producing pancreatic β cells in type 1 diabetes through HLA class I–restricted presentation of self-antigens. Combinatorial peptide library screening was used to produce a preferred peptide recognition landscape for a patient-derived T cell receptor (TCR) that recognized the preproinsulin-derived (PPI-derived) peptide sequence LWMRLLPLL in the context of disease risk allele HLA A*24:02. Data were used to generate a strong superagonist peptide, enabling production of an autoimmune HLA A*24:02–peptide–TCR structure by crystal seeding. TCR binding to the PPI epitope was strongly focused on peptide residues Arg4 and Leu5, with more flexibility at other positions, allowing the TCR to strongly engage many peptides derived from pathogenic bacteria. We confirmed an epitope from Klebsiella that was recognized by PPI-reactive T cells from 3 of 3 HLA A*24:02+ patients. Remarkably, the same epitope selected T cells from 7 of 8 HLA A*24+ healthy donors that cross-reacted with PPI, leading to recognition and killing of HLA A*24:02+ cells expressing PPI. These data provide a mechanism by which molecular mimicry between pathogen and self-antigens could have resulted in the breaking of self-tolerance to initiate disease. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
3. Structure-guided engineering of immunotherapies targeting TRBC1 and TRBC2 in T cell malignancies
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Ferrari, Mathieu, primary, Righi, Matteo, additional, Baldan, Vania, additional, Wawrzyniecka, Patrycja, additional, Bulek, Anna, additional, Kinna, Alexander, additional, Ma, Biao, additional, Bughda, Reyisa, additional, Akbar, Zulaikha, additional, Srivastava, Saket, additional, Gannon, Isaac, additional, Robson, Mathew, additional, Sillibourne, James, additional, Jha, Ram, additional, El-Kholy, Mohamed, additional, Amin, Oliver Muhammad, additional, Kokalaki, Evangelia, additional, Banani, Mohammed Amin, additional, Hussain, Rehan, additional, Day, William, additional, Lim, Wen Chean, additional, Ghongane, Priyanka, additional, Hopkins, Jade R., additional, Jungherz, Dennis, additional, Herling, Marco, additional, Welin, Martin, additional, Surade, Sachin, additional, Dyson, Michael, additional, McCafferty, John, additional, Logan, Derek, additional, Cordoba, Shaun, additional, Thomas, Simon, additional, Sewell, Andrew, additional, Maciocia, Paul, additional, Onuoha, Shimobi, additional, and Pule, Martin, additional
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- 2024
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4. Dual targeting of CD19 and CD22 against B-ALL using a novel high-sensitivity aCD22 CAR
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Kokalaki, Evangelia, primary, Ma, Biao, additional, Ferrari, Mathieu, additional, Grothier, Thomas, additional, Hazelton, Warren, additional, Manzoor, Somayya, additional, Costu, Eren, additional, Taylor, Julia, additional, Bulek, Anna, additional, Srivastava, Saket, additional, Gannon, Isaac, additional, Jha, Ram, additional, Gealy, Rosalind, additional, Stanczuk, Lukas, additional, Rizou, Tatiana, additional, Robson, Mathew, additional, El-Kholy, Mohamed, additional, Baldan, Vania, additional, Righi, Matteo, additional, Sillibourne, James, additional, Thomas, Simon, additional, Onuoha, Shimobi, additional, Cordoba, Shaun, additional, and Pule, Martin, additional
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- 2024
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- View/download PDF
5. Designer Small-Molecule Control System Based on Minocycline-Induced Disruption of Protein–Protein Interaction
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Jha, Ram, primary, Kinna, Alexander, additional, Hotblack, Alastair, additional, Bughda, Reyisa, additional, Bulek, Anna, additional, Gannon, Isaac, additional, Ilca, Tudor, additional, Allen, Christopher, additional, Lamb, Katarina, additional, Dolor, Abigail, additional, Scott, Ian, additional, Parekh, Farhaan, additional, Sillibourne, James, additional, Cordoba, Shaun, additional, Onuoha, Shimobi, additional, Thomas, Simon, additional, Ferrari, Mathieu, additional, and Pule, Martin, additional
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- 2024
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6. Designer small molecule control system based on Minocycline induced disruption of protein-protein interaction.
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Jha, Ram, primary, Kinna, Alexander, additional, Hotblack, Alastair, additional, Bughda, Reyisa, additional, Bulek, Anna, additional, Gannon, Isaac, additional, Ilca, Tudor, additional, Allen, Christopher, additional, Lamb, Katarina, additional, Dolor, Abigail, additional, Parekh, Farhaan, additional, Sillibourne, James, additional, Cordoba, Shaun P, additional, Onuoha, Shimobi C, additional, Thomas, Simon, additional, Ferrari, Mathieu, additional, and Pule, Martin, additional
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- 2023
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7. Exploration of T cell immune responses by expression of a dominant-negative SHP1 and SHP2
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Taylor, Julia, primary, Bulek, Anna, additional, Gannon, Isaac, additional, Robson, Mathew, additional, Kokalaki, Evangelia, additional, Grothier, Thomas, additional, McKenzie, Callum, additional, El-Kholy, Mohamed, additional, Stavrou, Maria, additional, Traynor-White, Charlotte, additional, Lim, Wen Chean, additional, Panagiotou, Panagiota, additional, Srivastava, Saket, additional, Baldan, Vania, additional, Sillibourne, James, additional, Ferrari, Mathieu, additional, Pule, Martin, additional, and Thomas, Simon, additional
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- 2023
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8. Hotspot autoimmune T cell receptor binding underlies pathogen and insulin peptide cross-reactivity
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Cole, David K., Bulek, Anna M., Dolton, Garry, Schauenberg, Andrea J., Szomolay, Barbara, Rittase, William, Trimby, Andrew, Jothikumar, Prithiviraj, Fuller, Anna, Skowera, Ania, Rossjohn, Jamie, Zhu, Cheng, Miles, John J., Peakman, Mark, Wooldridge, Linda, Rizkallah, Pierre J., and Sewell, Andrew K.
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Cross reactions (Immunology) -- Observations ,Cell receptors -- Health aspects ,Autoimmune diseases -- Development and progression ,Health care industry - Abstract
The cross-reactivity of T cells with pathogen- and self-derived peptides has been implicated as a pathway involved in the development of autoimmunity. However, the mechanisms that allow the clonal T cell antigen receptor (TCR) to functionally engage multiple peptide-major histocompatibility complexes (pMHC) are unclear. Here, we studied multiligand discrimination by a human, preproinsulin reactive, MHC class-I-restricted [CD8.sup.+] T cell clone (1E6) that can recognize over 1 million different peptides. We generated high-resolution structures of the 1E6 TCR bound to 7 altered peptide ligands, including a pathogenderived peptide that was an order of magnitude more potent than the natural self-peptide. Evaluation of these structures demonstrated that binding was stabilized through a conserved lock-and-key-like minimal binding footprint that enables 1E6 TCR to tolerate vast numbers of substitutions outside of this so-called hotspot. Highly potent antigens of the 1E6 TCR engaged with a strong antipathogen-like binding affinity; this engagement was governed though an energetic switch from an enthalpically to entropically driven interaction compared with the natural autoimmune ligand. Together, these data highlight how T cell cross-reactivity with pathogen-derived antigens might break self-tolerance to induce autoimmune disease., Introduction T cells perform an essential role in adaptive immunity by interrogating the host proteome for anomalies, classically by recognizing peptides bound in major histocompatibility (MHC) molecules at the cell [...]
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- 2016
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9. Structure-Guided Engineering of Immunotherapies Targeting TRBC1 and TRBC2 in T Cell Malignancies
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Ferrari, Mathieu, primary, Baldan, Vania, additional, Wawrzyniecka, Patrycja, additional, Bulek, Anna, additional, Kinna, Alex, additional, Ma, Biao, additional, Bugda, Reyisa, additional, Akbar, Zulaikha, additional, Srivast, Saket, additional, Ghongane, Priyankha, additional, Gannon, Isaac, additional, Robson, Matthew, additional, Sillibourne, James, additional, Jha, Ram, additional, Lim, Wen Chean, additional, Hopkins, Jade, additional, Welin, Martin, additional, Surade, Sachin, additional, Dyson, Michael, additional, McCafferty, John, additional, Cordoba, Shaun, additional, Thomas, Simon, additional, Logan, Derek, additional, Sewell, Andy, additional, Maciocia, Paul, additional, Onuoha, Shimobi, additional, and Pule, Martin, additional
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- 2022
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10. T cell receptor alpha variable 12‐2 bias in the immunodominant response to Yellow fever virus
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Bovay, Amandine, Zoete, Vincent, Dolton, Garry, Bulek, Anna M., Cole, David K., Rizkallah, Pierre J., Fuller, Anna, Beck, Konrad, Michielin, Olivier, Speiser, Daniel E., Sewell, Andrew K., and Fuertes Marraco, Silvia A.
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Cytotoxicity, Immunologic ,Germline ,Receptors, Antigen, T-Cell, alpha-beta ,Adaptive immunity ,Epitopes, T-Lymphocyte ,T-Cell Antigen Receptor Specificity ,CD8-Positive T-Lymphocytes ,Lymphocyte Activation ,Cell Line ,Adaptive Immunity/genetics ,CD8-Positive T-Lymphocytes/physiology ,Clonal Selection, Antigen-Mediated ,Clone Cells ,Complementarity Determining Regions/genetics ,Epitopes, T-Lymphocyte/metabolism ,HLA-A2 Antigen/metabolism ,Humans ,Immunodominant Epitopes/metabolism ,Receptors, Antigen, T-Cell, alpha-beta/genetics ,Viral Proteins/metabolism ,Viral Vaccines/immunology ,Yellow Fever/genetics ,Yellow Fever/immunology ,Yellow fever virus/physiology ,Antigen recognition ,T cell receptor Alpha Variable (TRAV)-12-2 ,T cell receptor bias ,Yellow Fever virus ,Viral Proteins ,HLA-A2 Antigen ,Yellow Fever ,Basic ,Research Articles ,Immunodominant Epitopes ,Viral Vaccines ,Complementarity Determining Regions ,Research Article|Basic ,T cell receptor Alpha Variable (TRAV)‐12‐2 - Abstract
The repertoire of human αβ T-cell receptors (TCRs) is generated via somatic recombination of germline gene segments. Despite this enormous variation, certain epitopes can be immunodominant, associated with high frequencies of antigen-specific T cells and/or exhibit bias toward a TCR gene segment. Here, we studied the TCR repertoire of the HLA-A*0201-restricted epitope LLWNGPMAV (hereafter, A2/LLW) from Yellow Fever virus, which generates an immunodominant CD8 + T cell response to the highly effective YF-17D vaccine. We discover that these A2/LLW-specific CD8 + T cells are highly biased for the TCR α chain TRAV12-2. This bias is already present in A2/LLW-specific naïve T cells before vaccination with YF-17D. Using CD8 + T cell clones, we show that TRAV12-2 does not confer a functional advantage on a per cell basis. Molecular modeling indicated that the germline-encoded complementarity determining region (CDR) 1α loop of TRAV12-2 critically contributes to A2/LLW binding, in contrast to the conventional dominant dependence on somatically rearranged CDR3 loops. This germline component of antigen recognition may explain the unusually high precursor frequency, prevalence and immunodominance of T-cell responses specific for the A2/LLW epitope.
- Published
- 2017
11. TCR-induced alteration of primary MHC peptide anchor residue
- Author
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Madura, Florian, Rizkallah, Pierre J., Legut, Mateusz, Holland, Christopher J., Fuller, Anna, Bulek, Anna, Schauenburg, Andrea J., Trimby, Andrew, Hopkins, Jade R., Wells, Stephen A., Godkin, Andrew, Miles, John J., Sami, Malkit, Li, Yi, Liddy, Nathaniel, Jakobsen, Bent K., Loveridge, E. Joel, Cole, David K., and Sewell, Andrew K.
- Abstract
The HLA‐A*02:01‐restricted decapeptide EAAGIGILTV, derived from melanoma antigen recognized by T‐cells‐1 (MART‐1) protein, represents one of the best‐studied tumor associated T‐cell epitopes, but clinical results targeting this peptide have been disappointing. This limitation may reflect the dominance of the nonapeptide, AAGIGILTV, at the melanoma cell surface. The decapeptide and nonapeptide are presented in distinct conformations by HLA‐A*02:01 and TCRs from clinically relevant T‐cell clones recognize the nonapeptide poorly. Here, we studied the MEL5 TCR that potently recognizes the nonapeptide. The structure of the MEL5‐HLA‐A*02:01‐AAGIGILTV complex revealed an induced fit mechanism of antigen recognition involving altered peptide–MHC anchoring. This “flexing” at the TCR–peptide–MHC interface to accommodate the peptide antigen explains previously observed incongruences in this well‐studied system and has important implications for future therapeutic approaches. Finally, this study expands upon the mechanisms by which molecular plasticity can influence antigen recognition by T cells.
- Published
- 2019
12. In Silico and Structural Analyses Demonstrate That Intrinsic Protein Motions Guide T Cell Receptor Complementarity Determining Region Loop Flexibility
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Holland, Christopher J., Maclachlan, Bruce J., Bianchi, Valentina, Hesketh, Sophie J., Morgan, Richard, Vickery, Owen, Bulek, Anna M., Fuller, Anna, Godkin, Andrew, Sewell, Andrew K., Rizkallah, Pierre J., Stephen Wells, and Cole, David K.
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complementarity determining regions loops ,T cell receptor ,T-cells ,X-ray crystallography ,computational simulations ,protein flexibility ,Immunology ,Immunology and Allergy ,chemical and pharmacologic phenomena ,Original Research - Abstract
T-cell immunity is controlled by T cell receptor (TCR) binding to peptide major histocompatibility complexes (pMHCs). The nature of the interaction between these two proteins has been the subject of many investigations because of its central role in immunity against pathogens, cancer, in autoimmunity, and during organ transplant rejection. Crystal structures comparing unbound and pMHC-bound TCRs have revealed flexibility at the interaction interface, particularly from the perspective of the TCR. However, crystal structures represent only a snapshot of protein conformation that could be influenced through biologically irrelevant crystal lattice contacts and other factors. Here, we solved the structures of three unbound TCRs from multiple crystals. Superposition of identical TCR structures from different crystals revealed some conformation differences of up to 5 Å in individual complementarity determining region (CDR) loops that are similar to those that have previously been attributed to antigen engagement. We then used a combination of rigidity analysis and simulations of protein motion to reveal the theoretical potential of TCR CDR loop flexibility in unbound state. These simulations of protein motion support the notion that crystal structures may only offer an artifactual indication of TCR flexibility, influenced by crystallization conditions and crystal packing that is inconsistent with the theoretical potential of intrinsic TCR motions.
- Published
- 2018
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13. Dual molecular mechanisms govern escape at immunodominant HLA A2-restricted HIV epitope
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Cole, David K., Fuller, Anna, Dolton, Garry, Zervoudi, Efthalia, Legut, Mateusz, Miles, Kim, Blanchfield, Lori, Madura, Florian, Holland, Christopher J., Bulek, Anna M., Bridgeman, John S., Miles, John J., Schauenburg, Andrea J. A., Beck, Konrad, Evavold, Brian D., Rizkallah, Pierre J., and Sewell, Andrew K.
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chemical and pharmacologic phenomena ,R1 - Abstract
Serial accumulation of mutations to fixation in the SLYNTVATL (SL9) immunodominant, HIV p17 Gag-derived, HLA A2-restricted CTL epitope produce the SLFNTIAVL triple mutant ‘ultimate’ escape variant. These mutations in solvent-exposed residues are believed to interfere with TCR recognition, although confirmation has awaited structural verification. Here, we solved a TCR co-complex structure with SL9 and the triple escape mutant to determine the mechanism of immune escape in this eminent system. We show that, in contrast to prevailing hypotheses, the main TCR contact residue is 4N and the dominant mechanism of escape is not via lack of TCR engagement. Instead, mutation of solvent exposed residues in the peptide destabilize the peptide-HLA and reduce peptide density at the cell surface. These results highlight the extraordinary lengths that HIV employs to evade detection by high-affinity TCRs with a broad peptide-binding footprint and necessitate reevaluation of this exemplar model of HIV TCR escape.
- Published
- 2017
14. Structure Guided Engineering of Highly Specific Chimeric Antigen Receptors for the Treatment of T Cell Lymphomas
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Onuoha, Shimobi, primary, Ferrari, Mathieu, additional, Bulek, Anna, additional, Bughda, Reyisa, additional, Manzoor, Somayya, additional, Srivastava, Saket, additional, Ma, Biao, additional, Karattil, Rajesh, additional, Kinna, Alex, additional, Wawrzyniecka, Patrycja, additional, Thomas, Simon, additional, Cordoba, Shaun P, additional, Maciocia, Paul, additional, and Pule, Martin, additional
- Published
- 2018
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15. Structural mechanism underpinning cross-reactivity of a CD8+ T-cell clone that recognises a peptide derived from human telomerase reverse transcriptase
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Cole, David K., Berg, Hugo van den, Lloyd, Angharad, Crowther, Michael D., Beck, Konrad, Ekeruche-Makinde, Julia, Miles, John J., Bulek, Anna M., Dolton, Garry, Schauenburg, Andrea J., Wall, Aaron, Fuller, Anna, Clement, Mathew, Laugel, Bruno, Rizkallah, Pierre J., Wooldridge, Linda, and Sewell, Andrew K.
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Biochemistry & Molecular Biology ,Immunology ,T cells ,Receptors, Antigen, T-Cell ,chemical and pharmacologic phenomena ,CD8-Positive T-Lymphocytes ,Cross Reactions ,telomerase ,BETA-CELLS ,CLASS-I ,BINDING ,Humans ,QD ,tumor immunology ,ANTIGEN RECOGNITION ,SPECIFICITY ,Cells, Cultured ,AFFINITY ,X-ray crystallography ,CARDIOVASCULAR TOXICITY ,Science & Technology ,RECEPTOR RECOGNITION ,11 Medical And Health Sciences ,06 Biological Sciences ,T cell degeneracy ,R1 ,MAJOR HISTOCOMPATIBILITY COMPLEX ,peptides ,T cell receptor ,03 Chemical Sciences ,Life Sciences & Biomedicine ,surface plasmon resonance (SPR) ,TCR - Abstract
T-cell cross-reactivity is essential for effective immune surveillance, but has also been implicated as a pathway to autoimmunity. Previous studies have demonstrated that T-cell receptors (TCRs) that focus on a minimal motif within the peptide are able to facilitate a high level of T-cell cross-reactivity. However, the structural database shows that most TCRs exhibit less focussed antigen binding involving contact with more peptide residues. To further explore the structural features that allow the clonally expressed TCR to functionally engage with multiple peptide-major histocompatibility complexes (pMHCs), we examined the ILA1 CD8+ T-cell clone that responds to a peptide sequence derived from human telomerase reverse transcriptase (hTERT). The ILA1 TCR contacted its pMHC with a broad peptide-binding footprint encompassing spatially distant peptide residues. Despite the lack of focused TCR-peptide binding , the ILA1 T-cell clone was still cross-reactive. Overall, the TCR-peptide contacts apparent in the structure correlated well with the level of degeneracy at different peptide positions. Thus, the ILA1 TCR was less tolerant of changes at peptide residues that were at, or adjacent to, key contact sites. This study provides new insights into the molecular mechanisms that control T-cell cross-reactivity, with important implications for pathogen surveillance, autoimmunity and transplant rejection.
- Published
- 2017
16. A molecular switch abrogates glycoprotein 100 (gp100) T-cell Receptor (TCR) targeting of a human melanoma antigen
- Author
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Bianchi, Valentina, Bulek, Anna, Fuller, Anna, Lloyd, Angharad, Attaf, Meriem, Rizkallah, Pierre J., Dolton, Garry, Sewell, Andrew K., and Cole, David K.
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chemical and pharmacologic phenomena - Abstract
Human CD8+ cytotoxic T lymphocytes can mediate tumor regression in melanoma through the specific recognition of HLA-restricted peptides. Because of the relatively weak affinity of most anti-cancer T-cell receptors (TCRs), there is growing emphasis on immunizing melanoma patients with altered peptide ligands in order to induce strong anti-tumor immunity capable of breaking tolerance toward these self-antigens. However, previous studies have shown that these immunogenic designer peptides are not always effective. The melanocyte differentiation protein, glycoprotein 100 (gp100), encodes a naturally processed epitope that is an attractive target for melanoma immunotherapies, in particular peptide-based vaccines. Previous studies have shown that substitutions at peptide residue Glu3 have a broad negative impact on polyclonal T-cell responses. Here, we describe the first atomic structure of a natural cognate TCR in complex with this gp100 epitope and highlight the relatively high affinity of the interaction. Alanine scan mutagenesis performed across the gp100280–288 peptide showed that Glu3 was critically important for TCR binding. Unexpectedly, structural analysis demonstrated that the Glu3 → Ala substitution resulted in a molecular switch that was transmitted to adjacent residues, abrogating TCR binding and T-cell recognition. These findings help to clarify the mechanism of T-cell recognition of gp100 during melanoma responses and could direct the development of altered peptides for vaccination.
- Published
- 2016
17. Coreceptor Scanning by the T Cell Receptor Provides a Mechanism for T Cell Tolerance
- Author
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Institute for Medical Engineering and Science, Massachusetts Institute of Technology. Department of Biological Engineering, Massachusetts Institute of Technology. Department of Chemical Engineering, Massachusetts Institute of Technology. Department of Chemistry, Massachusetts Institute of Technology. Department of Physics, Prabhakar, Arvind S., Chakraborty, Arup K., Stepanek, Ondrej, Osswald, Celine, King, Carolyn G., Bulek, Anna, Naeher, Dieter, Beaufils-Hugot, Marina, Abanto, Michael L., Galati, Virginie, Hausmann, Barbara, Lang, Rosemarie, Cole, David K., Huseby, Eric S., Sewell, Andrew K., Palmer, Ed, Institute for Medical Engineering and Science, Massachusetts Institute of Technology. Department of Biological Engineering, Massachusetts Institute of Technology. Department of Chemical Engineering, Massachusetts Institute of Technology. Department of Chemistry, Massachusetts Institute of Technology. Department of Physics, Prabhakar, Arvind S., Chakraborty, Arup K., Stepanek, Ondrej, Osswald, Celine, King, Carolyn G., Bulek, Anna, Naeher, Dieter, Beaufils-Hugot, Marina, Abanto, Michael L., Galati, Virginie, Hausmann, Barbara, Lang, Rosemarie, Cole, David K., Huseby, Eric S., Sewell, Andrew K., and Palmer, Ed
- Abstract
In the thymus, high-affinity, self-reactive thymocytes are eliminated from the pool of developing T cells, generating central tolerance. Here, we investigate how developing T cells measure self-antigen affinity. We show that very few CD4 or CD8 coreceptor molecules are coupled with the signal-initiating kinase, Lck. To initiate signaling, an antigen-engaged T cell receptor (TCR) scans multiple coreceptor molecules to find one that is coupled to Lck; this is the first and rate-limiting step in a kinetic proofreading chain of events that eventually leads to TCR triggering and negative selection. MHCII-restricted TCRs require a shorter antigen dwell time (0.2 s) to initiate negative selection compared to MHCI-restricted TCRs (0.9 s) because more CD4 coreceptors are Lck-loaded compared to CD8. We generated a model (Lck come&stay/signal duration) that accurately predicts the observed differences in antigen dwell-time thresholds used by MHCI- and MHCII-restricted thymocytes to initiate negative selection and generate self-tolerance., National Institutes of Health (U.S.) (Grant 1-P01-AI091580)
- Published
- 2016
18. T cell receptor alpha variable 12‐2 bias in the immunodominant response to Yellow fever virus.
- Author
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Bovay, Amandine, Zoete, Vincent, Dolton, Garry, Bulek, Anna M., Cole, David K., Rizkallah, Pierre J., Fuller, Anna, Beck, Konrad, Michielin, Olivier, Speiser, Daniel E., Sewell, Andrew K., and Fuertes Marraco, Silvia A.
- Abstract
Abstract: The repertoire of human αβ T‐cell receptors (TCRs) is generated via somatic recombination of germline gene segments. Despite this enormous variation, certain epitopes can be immunodominant, associated with high frequencies of antigen‐specific T cells and/or exhibit bias toward a TCR gene segment. Here, we studied the TCR repertoire of the HLA‐A*0201‐restricted epitope LLWNGPMAV (hereafter, A2/LLW) from Yellow Fever virus, which generates an immunodominant CD8
+ T cell response to the highly effective YF‐17D vaccine. We discover that these A2/LLW‐specific CD8+ T cells are highly biased for the TCR α chain TRAV12‐2. This bias is already present in A2/LLW‐specific naïve T cells before vaccination with YF‐17D. Using CD8+ T cell clones, we show that TRAV12‐2 does not confer a functional advantage on a per cell basis. Molecular modeling indicated that the germline‐encoded complementarity determining region (CDR) 1α loop of TRAV12‐2 critically contributes to A2/LLW binding, in contrast to the conventional dominant dependence on somatically rearranged CDR3 loops. This germline component of antigen recognition may explain the unusually high precursor frequency, prevalence and immunodominance of T‐cell responses specific for the A2/LLW epitope. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
19. Structural basis for ineffective T‐cell responses to MHC anchor residue‐improved “heteroclitic” peptides
- Author
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Madura, Florian, primary, Rizkallah, Pierre J., additional, Holland, Christopher J., additional, Fuller, Anna, additional, Bulek, Anna, additional, Godkin, Andrew J., additional, Schauenburg, Andrea J., additional, Cole, David K., additional, and Sewell, Andrew K., additional
- Published
- 2014
- Full Text
- View/download PDF
20. Coreceptor Scanning by the T Cell Receptor Provides a Mechanism for T Cell Tolerance
- Author
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Stepanek, Ondrej, primary, Prabhakar, Arvind S., additional, Osswald, Celine, additional, King, Carolyn G., additional, Bulek, Anna, additional, Naeher, Dieter, additional, Beaufils-Hugot, Marina, additional, Abanto, Michael L., additional, Galati, Virginie, additional, Hausmann, Barbara, additional, Lang, Rosemarie, additional, Cole, David K., additional, Huseby, Eric S., additional, Sewell, Andrew K., additional, Chakraborty, Arup K., additional, and Palmer, Ed, additional
- Published
- 2014
- Full Text
- View/download PDF
21. Structural basis for ineffective T-cell responses to MHC anchor residue-improved 'heteroclitic' peptides.
- Author
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Madura, Florian, Rizkallah, Pierre J., Holland, Christopher J., Fuller, Anna, Bulek, Anna, Godkin, Andrew J., Schauenburg, Andrea J., Cole, David K., and Sewell, Andrew K.
- Abstract
MHC anchor residue-modified 'heteroclitic' peptides have been used in many cancer vaccine trials and often induce greater immune responses than the wild-type peptide. The best-studied system to date is the decamer MART-1/Melan-A
26-35 peptide, EAAGIGILTV, where the natural alanine at position 2 has been modified to leucine to improve human leukocyte antigen (HLA)-A*0201 anchoring. The resulting E LAGIGILTV peptide has been used in many studies. We recently showed that T cells primed with the E LAGIGILTV peptide can fail to recognize the natural tumor-expressed peptide efficiently, thereby providing a potential molecular reason for why clinical trials of this peptide have been unsuccessful. Here, we solved the structure of a TCR in complex with HLA-A*0201-EAAGIGILTV peptide and compared it with its heteroclitic counterpart , HLA-A*0201-E LAGIGILTV. The data demonstrate that a suboptimal anchor residue at position 2 enables the TCR to 'pull' the peptide away from the MHC binding groove, facilitating extra contacts with both the peptide and MHC surface. These data explain how a TCR can distinguish between two epitopes that differ by only a single MHC anchor residue and demonstrate how weak MHC anchoring can enable an induced-fit interaction with the TCR. Our findings constitute a novel demonstration of the extreme sensitivity of the TCR to minor alterations in peptide conformation. [ABSTRACT FROM AUTHOR]- Published
- 2015
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- View/download PDF
22. Structural Mechanism Underpinning Cross-reactivity of a CD8+ T-cell Clone That Recognizes a Peptide Derived from Human Telomerase Reverse Transcriptase.
- Author
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Cole, David K., van den Berg, Hugo A., Lloyd, Angharad, Crowther, Michael D., Beck, Konrad, Ekeruche-Makinde, Julia, Miles, John J., Bulek, Anna M., Dolton, Garry, Schauenburg, Andrea J., Wall, Aaron, Fuller, Anna, Clement, Mathew, Laugel, Bruno, Rizkallah, Pierre J., Wooldridge, Linda, and Sewell, Andrew K.
- Subjects
- *
T cells , *TELOMERASE reverse transcriptase , *AUTOIMMUNITY , *PROTEIN expression , *MAJOR histocompatibility complex - Abstract
T-cell cross-reactivity is essential for effective immune surveillance but has also been implicated as a pathway to autoimmunity. Previous studies have demonstrated that T-cell receptors (TCRs) that focus on a minimal motif within the peptide are able to facilitate a high level of T-cell cross-reactivity. However, the structural database shows that most TCRs exhibit less focused antigen binding involving contact with more peptide residues. To further explore the structural features that allow the clonally expressed TCR to functionally engage with multiple peptide-major histocompatibility complexes (pMHCs), we examined the ILA1 CD8+ T-cell clone that responds to a peptide sequence derived from human telomerase reverse transcriptase. The ILA1 TCR contacted its pMHC with a broad peptide binding footprint encompassing spatially distant peptide residues. Despite the lack of focused TCR-peptide binding, the ILA1 T-cell clone was still cross-reactive. Overall, the TCR-peptide contacts apparent in the structure correlated well with the level of degeneracy at different peptide positions. Thus, the ILA1 TCR was less tolerant of changes at peptide residues that were at, or adjacent to, key contact sites. This study provides new insights into the molecular mechanisms that control T-cell cross-reactivity with important implications for pathogen surveillance, autoimmunity, and transplant rejection. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
23. TCR-induced alteration of primary MHC peptide anchor residue.
- Author
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Madura F, Rizkallah PJ, Legut M, Holland CJ, Fuller A, Bulek A, Schauenburg AJ, Trimby A, Hopkins JR, Wells SA, Godkin A, Miles JJ, Sami M, Li Y, Liddy N, Jakobsen BK, Loveridge EJ, Cole DK, and Sewell AK
- Subjects
- Amino Acids, Antigen Presentation, Binding Sites, Cells, Cultured, Clone Cells, HLA-A2 Antigen chemistry, HLA-A2 Antigen metabolism, Humans, Lymphocyte Activation, MART-1 Antigen chemistry, Melanoma therapy, Peptides chemistry, Protein Binding, Protein Conformation, Receptors, Antigen, T-Cell genetics, T-Lymphocytes transplantation, Immunodominant Epitopes metabolism, Immunotherapy, Adoptive methods, MART-1 Antigen metabolism, Melanoma immunology, Peptides metabolism, Receptors, Antigen, T-Cell metabolism, T-Lymphocytes immunology
- Abstract
The HLA-A*02:01-restricted decapeptide EAAGIGILTV, derived from melanoma antigen recognized by T-cells-1 (MART-1) protein, represents one of the best-studied tumor associated T-cell epitopes, but clinical results targeting this peptide have been disappointing. This limitation may reflect the dominance of the nonapeptide, AAGIGILTV, at the melanoma cell surface. The decapeptide and nonapeptide are presented in distinct conformations by HLA-A*02:01 and TCRs from clinically relevant T-cell clones recognize the nonapeptide poorly. Here, we studied the MEL5 TCR that potently recognizes the nonapeptide. The structure of the MEL5-HLA-A*02:01-AAGIGILTV complex revealed an induced fit mechanism of antigen recognition involving altered peptide-MHC anchoring. This "flexing" at the TCR-peptide-MHC interface to accommodate the peptide antigen explains previously observed incongruences in this well-studied system and has important implications for future therapeutic approaches. Finally, this study expands upon the mechanisms by which molecular plasticity can influence antigen recognition by T cells., (© 2019 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2019
- Full Text
- View/download PDF
24. Dual Molecular Mechanisms Govern Escape at Immunodominant HLA A2-Restricted HIV Epitope.
- Author
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Cole DK, Fuller A, Dolton G, Zervoudi E, Legut M, Miles K, Blanchfield L, Madura F, Holland CJ, Bulek AM, Bridgeman JS, Miles JJ, Schauenburg AJA, Beck K, Evavold BD, Rizkallah PJ, and Sewell AK
- Abstract
Serial accumulation of mutations to fixation in the SLYNTVATL (SL9) immunodominant, HIV p17 Gag-derived, HLA A2-restricted cytotoxic T lymphocyte epitope produce the SLFNTIAVL triple mutant "ultimate" escape variant. These mutations in solvent-exposed residues are believed to interfere with TCR recognition, although confirmation has awaited structural verification. Here, we solved a TCR co-complex structure with SL9 and the triple escape mutant to determine the mechanism of immune escape in this eminent system. We show that, in contrast to prevailing hypotheses, the main TCR contact residue is 4N and the dominant mechanism of escape is not via lack of TCR engagement. Instead, mutation of solvent-exposed residues in the peptide destabilise the peptide-HLA and reduce peptide density at the cell surface. These results highlight the extraordinary lengths that HIV employs to evade detection by high-affinity TCRs with a broad peptide-binding footprint and necessitate re-evaluation of this exemplar model of HIV TCR escape.
- Published
- 2017
- Full Text
- View/download PDF
25. Structural Mechanism Underpinning Cross-reactivity of a CD8+ T-cell Clone That Recognizes a Peptide Derived from Human Telomerase Reverse Transcriptase.
- Author
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Cole DK, van den Berg HA, Lloyd A, Crowther MD, Beck K, Ekeruche-Makinde J, Miles JJ, Bulek AM, Dolton G, Schauenburg AJ, Wall A, Fuller A, Clement M, Laugel B, Rizkallah PJ, Wooldridge L, and Sewell AK
- Subjects
- Cells, Cultured, Cross Reactions, Humans, CD8-Positive T-Lymphocytes chemistry, CD8-Positive T-Lymphocytes immunology, Peptides chemistry, Peptides immunology, Receptors, Antigen, T-Cell chemistry, Receptors, Antigen, T-Cell immunology, Telomerase chemistry, Telomerase immunology
- Abstract
T-cell cross-reactivity is essential for effective immune surveillance but has also been implicated as a pathway to autoimmunity. Previous studies have demonstrated that T-cell receptors (TCRs) that focus on a minimal motif within the peptide are able to facilitate a high level of T-cell cross-reactivity. However, the structural database shows that most TCRs exhibit less focused antigen binding involving contact with more peptide residues. To further explore the structural features that allow the clonally expressed TCR to functionally engage with multiple peptide-major histocompatibility complexes (pMHCs), we examined the ILA1 CD8
+ T-cell clone that responds to a peptide sequence derived from human telomerase reverse transcriptase. The ILA1 TCR contacted its pMHC with a broad peptide binding footprint encompassing spatially distant peptide residues. Despite the lack of focused TCR-peptide binding, the ILA1 T-cell clone was still cross-reactive. Overall, the TCR-peptide contacts apparent in the structure correlated well with the level of degeneracy at different peptide positions. Thus, the ILA1 TCR was less tolerant of changes at peptide residues that were at, or adjacent to, key contact sites. This study provides new insights into the molecular mechanisms that control T-cell cross-reactivity with important implications for pathogen surveillance, autoimmunity, and transplant rejection., (© 2017 by The American Society for Biochemistry and Molecular Biology, Inc.)- Published
- 2017
- Full Text
- View/download PDF
26. A Molecular Switch Abrogates Glycoprotein 100 (gp100) T-cell Receptor (TCR) Targeting of a Human Melanoma Antigen.
- Author
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Bianchi V, Bulek A, Fuller A, Lloyd A, Attaf M, Rizkallah PJ, Dolton G, Sewell AK, and Cole DK
- Subjects
- CD8-Positive T-Lymphocytes pathology, Humans, Melanoma genetics, Melanoma pathology, Protein Structure, Quaternary, Receptors, Antigen, T-Cell genetics, gp100 Melanoma Antigen genetics, CD8-Positive T-Lymphocytes immunology, Melanoma immunology, Receptors, Antigen, T-Cell chemistry, Receptors, Antigen, T-Cell immunology, gp100 Melanoma Antigen chemistry, gp100 Melanoma Antigen immunology
- Abstract
Human CD8(+) cytotoxic T lymphocytes can mediate tumor regression in melanoma through the specific recognition of HLA-restricted peptides. Because of the relatively weak affinity of most anti-cancer T-cell receptors (TCRs), there is growing emphasis on immunizing melanoma patients with altered peptide ligands in order to induce strong anti-tumor immunity capable of breaking tolerance toward these self-antigens. However, previous studies have shown that these immunogenic designer peptides are not always effective. The melanocyte differentiation protein, glycoprotein 100 (gp100), encodes a naturally processed epitope that is an attractive target for melanoma immunotherapies, in particular peptide-based vaccines. Previous studies have shown that substitutions at peptide residue Glu(3) have a broad negative impact on polyclonal T-cell responses. Here, we describe the first atomic structure of a natural cognate TCR in complex with this gp100 epitope and highlight the relatively high affinity of the interaction. Alanine scan mutagenesis performed across the gp100(280-288) peptide showed that Glu(3) was critically important for TCR binding. Unexpectedly, structural analysis demonstrated that the Glu(3) → Ala substitution resulted in a molecular switch that was transmitted to adjacent residues, abrogating TCR binding and T-cell recognition. These findings help to clarify the mechanism of T-cell recognition of gp100 during melanoma responses and could direct the development of altered peptides for vaccination., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)
- Published
- 2016
- Full Text
- View/download PDF
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