Dataset Information

Characterization and clinical enrichment of HLA-C*07:02-restricted Cytomegalovirus-specific CD8+ T cells.

ABSTRACT: Human Cytomegalovirus (CMV) reactivation remains a major source of morbidity in patients after solid organ and hematopoietic stem cell transplantation (HSCT). Adoptive T cell therapy (ACT) with CMV-specific T cells is a promising therapeutic approach for HSCT recipients, but might be counteracted by CMV's immune evasion strategies. HLA-C*07:02 is less susceptible to viral immune evasion suggesting HLA-C*07:02-restricted viral epitopes as promising targets for ACT. For a better understanding of HLA-C*07:02-restricted CMV-specific T cells we used recently generated reversible HLA-C*07:02/IE-1 multimers (Streptamers) recognizing a CMV-derived Immediate-Early-1 (IE-1) epitope and analyzed phenotypic and functional T cell characteristics. Initially, we detected very high frequencies of HLA-C*07:02/IE-1 multimer+ T cells (median = 11.35%), as well as robust functional responses after stimulation with IE-1 peptide (IFN?+; median = 5.02%) in healthy individuals. However, MHC-multimer+ and IFN?-secreting T cell frequencies showed a relatively weak correlation (r2 = 0.77), which could be attributed to an unexpected contribution of CMV-epitope-independent KIR2DL2/3-binding of HLA-C*07:02/IE-1 multimers. Therefore, we developed a MHC-multimer double-staining approach against a cancer epitope-specific HLA-C*07:02 multimer to identify truly HLA-C*07:02/IE-1 epitope-specific T cells. The frequencies of these truly HLA-C*07:02/IE-1 multimer+ T cells were still high (median = 6.86%) and correlated now strongly (r2 = 0.96) with IFN?-secretion. Interestingly, HLA-C*07:02/IE-1-restricted T cells contain substantial numbers with a central memory T cell phenotype, indicating high expansion potential e.g. for ACT. In line with that, we developed a clinical enrichment protocol avoiding epitope-independent KIR-binding to make HLA-C*07:02/IE-1-restricted T cells available for ACT. Initial depletion of KIR-expressing CD8+ T cells followed by HLA-C*07:02/IE-1 Streptamer positive selection using paramagnetic labeling techniques allowed to enrich successfully HLA-C*07:02/IE-1-restricted T cells. Such specifically enriched populations of functional HLA-C*07:02/IE-1-restricted T cells with significant central memory T cell content could become a potent source for ACT.

SUBMITTER: Schlott F

PROVIDER: S-EPMC5831000 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

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Characterization and clinical enrichment of HLA-C*07:02-restricted Cytomegalovirus-specific CD8+ T cells.

Schlott Fabian F Steubl Dominik D Ameres Stefanie S Moosmann Andreas A Dreher Stefan S Heemann Uwe U Hösel Volker V Busch Dirk H DH Neuenhahn Michael M

PloS one 20180228 2

Human Cytomegalovirus (CMV) reactivation remains a major source of morbidity in patients after solid organ and hematopoietic stem cell transplantation (HSCT). Adoptive T cell therapy (ACT) with CMV-specific T cells is a promising therapeutic approach for HSCT recipients, but might be counteracted by CMV's immune evasion strategies. HLA-C*07:02 is less susceptible to viral immune evasion suggesting HLA-C*07:02-restricted viral epitopes as promising targets for ACT. For a better understanding of H ...[more]

PMID: 29489900

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Project description:BackgroundThe present study aimed to explore residues' properties interacting with HLA-A*02-restricted peptides on T-cell receptors (TCRs) and their effects on bond types of interaction and binding free energy.MethodsWe searched the crystal structures of HLA-A*02-restricted peptide-TCR complexes from the Protein Data Bank (PDB) database and subsequently collected relevant parameters. We then employed Schrodinger to analyze the bond types of interaction and Gromacs 2019 to evaluate the TCR-antigen peptide complex's molecular dynamics simulation. Finally, we compared the changes of bond types of interaction and binding free energy before and after residue substitution to ensure consistency of the conditions before and after residue substitution.ResultsThe main sites on the antigen peptides that formed the intermolecular interaction [hydrogen bond (HB) and pi stack] with TCRs were P4, P8, P2, and P6. The hydrophobicity of the amino acids inside or outside the disulfide bond of TCRs may be related to the intermolecular interaction and binding free energy between TCRs and peptides. Residues located outside the disulfide bond of TCR α or β chains and forming pi stack force played favorable roles in the complex intermolecular interaction and binding free energy. The residues of the TCR α or β chains that interacted with peptides were replaced by alanine (Ala) or glycine (Gly), and their intermolecular binding free energy of the complex had been improved. However, it had nothing to do with the formation of HB.ConclusionsThe findings of this study suggest that the hydrophobic nature of the amino acids inside or outside the disulfide bonds on the TCR may be associated with the intermolecular interaction and binding between the TCR and polypeptide. The residues located outside the TCR α or β single-chain disulfide bond and forming the pi-stack force showed a beneficial effect on the intermolecular interaction and binding of the complex. In addition, the part of the residues on the TCR α or β single chain that produced bond types of interaction with the polypeptide after being replaced by Ala or Gly, the intermolecular binding free energy of the complex was increased, regardless of whether HB was formed.

Dataset Information

Characterization and clinical enrichment of HLA-C*07:02-restricted Cytomegalovirus-specific CD8+ T cells.

Publications

Characterization and clinical enrichment of HLA-C*07:02-restricted Cytomegalovirus-specific CD8+ T cells.

Similar Datasets

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