Presentation Information
[P04-485]Induction of anergy in human T lymphocytes by exposure to single amino acid mutated synthetic antigen peptide
○Yoko Nakai-Futatsugi1 (1. The University of Osaka (Japan))
Keywords:
synthetic antigen peptide,T lymphocyte,anergy,human leucocyte antigen,in silico prediction,single cell RNA sequencing
[Purpose]
Anergy is a condition of immune T cells becoming sustainably inactive. Theoretically, it occurs when a T cell recognizes its antigen but cannot be active. Artificial induction of anergy to a specific T cell clone should provide a therapeutic strategy for autoimmune disease. One possible method for this is to expose a T cell to an unstably presented antigen, making the T cell bind to the antigen but not become active. The present study attempted to realize this condition in human T lymphocytes by exposing the cells to a synthetic antigen peptide that has a single amino acid mutation at the human leucocyte antigen (HLA)-binding anchor-residue.
[Method]
Peripheral blood mononuclear cells (PBMC) derived from HLAA24-positive healthy doners were pre-exposed to single amino acid mutated cytomegalovirus (CMV) antigen peptides for 24 hours, then were stimulated with the original non-mutated CMV-antigen peptide, followed by culture for two weeks. The cells were harvested and evaluated for the presence of CMV-recognizing T cell clones by flow cytometry, using fluorescence-conjugated HLA-A*24:02 CMV pp65 tetramer.
[Results]
By flow cytometry, induction of anergy in human T lymphocytes after exposure to single amino acid mutated synthetic antigen was somehow revealed, but the efficiency of induction differed among the specimen, and even for the same specimen, the results varied among the test-tubes, suggesting the stochasticity of this method. By gene expression profiling, CD4+/TSHZ2+ T cell population emerged after anergy-induction, but only in a small population evidencing the stochasticity of this method. By in silico protein structure prediction, requirement for optimal range of contact energy between the antigen and the HLA for successful anergy-induction was suggested.
[Consideration]
The present study tested two types of single amino acid mutation of the antigen, which were both not in the range of optimal contact energy predicted by in silico analysis. The next step of the study would be optimizing the mutation for efficient induction of anergy.
[Conclusion]
Despite the stochasticity, this was the first study to demonstrate anergy-induction by antigen-destabilization strategy using synthetic peptides in human cells[1].
[Reference]
[1] Y. Nakai-Futatsugi, bioRxiv (2025) 2025.04.15.649051
This work was supported by JSPS KAKENHI Grant Number 21H03097 and RIKEN Incentive Research Project FY2021.
Anergy is a condition of immune T cells becoming sustainably inactive. Theoretically, it occurs when a T cell recognizes its antigen but cannot be active. Artificial induction of anergy to a specific T cell clone should provide a therapeutic strategy for autoimmune disease. One possible method for this is to expose a T cell to an unstably presented antigen, making the T cell bind to the antigen but not become active. The present study attempted to realize this condition in human T lymphocytes by exposing the cells to a synthetic antigen peptide that has a single amino acid mutation at the human leucocyte antigen (HLA)-binding anchor-residue.
[Method]
Peripheral blood mononuclear cells (PBMC) derived from HLAA24-positive healthy doners were pre-exposed to single amino acid mutated cytomegalovirus (CMV) antigen peptides for 24 hours, then were stimulated with the original non-mutated CMV-antigen peptide, followed by culture for two weeks. The cells were harvested and evaluated for the presence of CMV-recognizing T cell clones by flow cytometry, using fluorescence-conjugated HLA-A*24:02 CMV pp65 tetramer.
[Results]
By flow cytometry, induction of anergy in human T lymphocytes after exposure to single amino acid mutated synthetic antigen was somehow revealed, but the efficiency of induction differed among the specimen, and even for the same specimen, the results varied among the test-tubes, suggesting the stochasticity of this method. By gene expression profiling, CD4+/TSHZ2+ T cell population emerged after anergy-induction, but only in a small population evidencing the stochasticity of this method. By in silico protein structure prediction, requirement for optimal range of contact energy between the antigen and the HLA for successful anergy-induction was suggested.
[Consideration]
The present study tested two types of single amino acid mutation of the antigen, which were both not in the range of optimal contact energy predicted by in silico analysis. The next step of the study would be optimizing the mutation for efficient induction of anergy.
[Conclusion]
Despite the stochasticity, this was the first study to demonstrate anergy-induction by antigen-destabilization strategy using synthetic peptides in human cells[1].
[Reference]
[1] Y. Nakai-Futatsugi, bioRxiv (2025) 2025.04.15.649051
This work was supported by JSPS KAKENHI Grant Number 21H03097 and RIKEN Incentive Research Project FY2021.
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