筛选和鉴定用于非微卫星高度不稳定结直肠癌免疫治疗的 HLA-A2 限制性新抗原表位

Colorectal cancer has one of the highest mortality rates among malignant tumors, and most patients with non-microsatellite instability-high (MSI-H) colorectal cancer do not benefit from targeted therapy or immune checkpoint inhibitors. Identification of immunogenic neoantigens is a promising strategy for inducing specific antitumor T cells for cancer immunotherapy.

Here, we screened potential high-frequency neoepitopes from non-MSI-H colorectal cancer and tested their abilities to induce tumor-specific cytotoxic T cell responses. Three HLA-A2-restricted neoepitopes (P31, P50, and P52) were immunogenic and could induce cytotoxic T lymphocytes in peripheral blood mononuclear cells from healthy donors and colorectal cancer patients. Cytotoxic T lymphocytes induced in HLA-A2. 1/K b transgenic mice could recognize and lyse mutant neoepitope-transfected HLA-A2 + cancer cells.

Adoptive transfer of cytotoxic T lymphocytes induced by the peptide pool of these three neoepitopes effectively inhibited tumor growth and increased the therapeutic effects of anti-PD-1 antibody. These results revealed the potential of high-frequency mutation-specific peptide-based immunotherapy as a personalized treatment approach for patients with non-MSI-H colorectal cancer.

The combination of adoptive T cell therapy based on these neoepitopes with immune checkpoint inhibitors, such as anti-PD-1, could provide a promising treatment strategy for non-MSI-H colorectal cancer.