Rapid selection and identification of functional CD8⁺ T cell epitopes from large peptide-coding libraries

Area of Science:

• Immunology
• Molecular Biology
• Genomics

Background:

• Cytotoxic CD8+ T cells are crucial for identifying and eliminating infected or malignant cells.
• Identifying naturally processed and major histocompatibility complex (MHC)-bound peptide epitopes that trigger T cell responses remains a significant challenge.

Purpose of the Study:

• To develop a deep and unbiased method for profiling T cell epitopes.
• To enable sensitive identification of naturally processed and MHC-presented peptide epitopes.

Main Methods:

• Utilized in vitro co-culture of CD8+ T cells with target cells engineered with high-complexity, epitope-encoding minigene libraries.
• Isolated target cells undergoing cytotoxic attack via fluorescence-activated cell sorting before apoptosis.
• Sequenced minigenes from sorted cells to identify recognized epitopes.

Main Results:

• Successfully validated the method using known murine T cell receptor/peptide-MHC pairs.
• Demonstrated the method's efficacy with diverse minigene-encoded epitope libraries.
• Achieved unambiguous and sensitive identification of naturally processed and MHC-presented peptide epitopes.

Conclusions:

• The developed method offers a powerful, highly parallelized approach for T cell epitope discovery.
• This technique overcomes previous challenges in comprehensive epitope profiling.
• Enables sensitive and accurate identification of functional T cell epitopes for immunological research.