Generation of cytotoxic T lymphocytes specific for native or modified peptides derived from the epidermal growth...

Area of Science:

• Oncology
• Immunology
• Molecular Biology

Background:

• The epidermal growth factor receptor pathway substrate 8 gene (Eps8) is overexpressed in various cancer cells but not normal tissues, making it a potential tumor antigen.
• Developing effective cancer immunotherapies requires identifying tumor-specific antigens.
• The HLA-A2.1 molecule is prevalent in the Chinese population, making it a relevant target for immunotherapy.

Purpose of the Study:

• To investigate the potential utility of Eps8-derived immunotherapy.
• To design and modify Eps8 native epitopes for enhanced binding affinity and immunogenicity to HLA-A2.1.
• To evaluate the efficacy of these epitopes in vitro and in vivo.

Main Methods:

• Utilized three computer-based algorithms to design eight native Eps8 epitopes.
• Modified three native peptides with moderate HLA-A2.1 binding affinity at anchor residue positions.
• Assessed binding affinity and dissociation rates of native and modified peptides on T2 cells.
• Conducted functional assays with human PBMCs and HLA-A2.1/K(b) transgenic mice to evaluate CTL responses, IFN-γ secretion, and cancer cell toxicity.

Main Results:

• Four modified Eps8 peptides exhibited enhanced binding affinity and lower dissociation rates to HLA-A2.1 molecules.
• Primed CTLs demonstrated HLA-A2.1-restricted and Eps8-specific cytotoxicity against diverse cancer cells.
• Two modified epitopes, p101-109-2L and p276-284-1Y9V, showed superior performance both in vitro and in vivo.
• Significant IFN-γ secretion was observed in functional assays.

Conclusions:

• Eps8-derived native and modified epitopes hold promise for cancer immunotherapy.
• These epitopes can elicit efficient anti-cancer immune responses in an HLA-A2.1-restricted manner.
• The identified epitopes may be beneficial for immunotherapy in HLA-A2.1 positive cancer patients across various tumor types.