The T210M substitution in the HLA-a*02:01 gp100 epitope strongly affects overall proteasomal cleavage site usage and antigen processing
| Autor: | Peter M. Kloetzel, Christin Keller, Michele Mishto, John Sidney, Kathrin Textoris-Taube, Petra Henklein, Juliane Liepe, Alessandro Sette |
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| Přispěvatelé: | NC3Rs (National Centre for the Replacement, Refinement and Reduction of Animals in Research) |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Biochemistry & Molecular Biology
Proteasome Endopeptidase Complex PEPTIDE HYDROLYSIS Immunology Antigen presentation DIVERSITY Epitopes T-Lymphocyte CD8-Positive T-Lymphocytes Major histocompatibility complex Biochemistry SEQUENCE Epitope Cell Line Tumor MHC class I BINDING HLA-A2 Antigen antigen processing Humans mutant Molecular Biology Cell Line Transformed Antigen Presentation Science & Technology biology Linear epitope PRESENTED PEPTIDES Antigen processing Immunogenicity INDUCTION T-cell receptor RECOGNITION IMMUNOPROTEASOMES Cell Biology 11 Medical And Health Sciences 06 Biological Sciences Molecular biology Cell biology Amino Acid Substitution HLA-B Antigens ubiquitin-dependent protease CELLS biology.protein protein degradation 03 Chemical Sciences Life Sciences & Biomedicine CTL EPITOPE gp100 Melanoma Antigen |
| Zdroj: | Journal of Biological Chemistry |
| Popis: | MHC class I-restricted epitopes, which carry a tumor-specific mutation resulting in improved MHC binding affinity, are preferred T cell receptor targets in innovative adoptive T cell therapies. However, T cell therapy requires efficient generation of the selected epitope. How such mutations may affect proteasome-mediated antigen processing has so far not been studied. Therefore, we analyzed by in vitro experiments the effect on antigen processing and recognition of a T210M exchange, which previously had been introduced into the melanoma gp100209-217 tumor epitope to improve the HLA-A*02:01 binding and its immunogenicity. A quantitative analysis of the main steps of antigen processing shows that the T210M exchange affects proteasomal cleavage site usage within the mutgp100201-230 polypeptide, leading to the generation of an unique set of cleavage products. The T210M substitution qualitatively affects the proteasome-catalyzed generation of spliced and non-spliced peptides predicted to bind HLA-A or -B complexes. The T210M substitution also induces an enhanced production of the mutgp100209-217 epitope and its N-terminally extended peptides. The T210M exchange revealed no effect on ERAP1-mediated N-terminal trimming of the precursor peptides. However, mutant N-terminally extended peptides exhibited significantly increased HLA-A*02:01 binding affinity and elicited CD8(+) T cell stimulation in vitro similar to the wtgp100209-217 epitope. Thus, our experiments demonstrate that amino acid exchanges within an epitope can result in the generation of an altered peptide pool with new antigenic peptides and in a wider CD8(+) T cell response also towards N-terminally extended versions of the minimal epitope. |
| Databáze: | OpenAIRE |
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