小鼠结肠癌新抗原 Glud1-V546I 及其 DC 疫苗能够在体内和体外诱导有效的抗肿瘤免疫应答

Objective: To develop a neoantigen peptide vaccine for personalized treatment of colorectal cancer (CRC), and to explore the feasibility and effectiveness of neoantigen peptide and its induced neoantigen reactive T cells (NRT) therapy for CRC. Methods: DNA and RNA were extracted from mouse CRC cell line CT26, followed by whole-exome and transcriptome sequencing to analyze tumor gene mutations and expression. Peptides with high immunogenicity were screened and synthesized through a machine learning based neoantigen prediction system. Mice were subcutaneously immunized with synthesized peptides, and the interferon (IFN)-γ level of splenocytes from immunized mice was determined using flow cytometry to screen peptides with strong immunogenicity. Afterwards, bone marrow-derived dendritic cells (BMDCs) loaded with immunogenic peptides were used to immunize mice bearing CRC model. The IFN-γ secretion ability by effector cells was determined by ELISPOT assay, and the cytotoxicity of γ secretion ability by effector cells was determined by ELISPOT assay, and the cytotoxicity of splenocytes from immunized mice was examined by time-resolved fluorescence immunoassay. In addition, the tumor growth and survival period of tumor-bearing mice were observed. Results: The neoantigen Glud1-V546I induced stronger IFN-γ secretion by NRT cells (P < 0.000 1). Compared with the wild peptide (Glud1-WT), Glud1-V546I induced higher IFN-γ secretion by NRT cells (P < 0.000 1) and stronger cytotoxicity (P < 0.000 1) in tumor-bearing mice. Meanwhile, Glud1-V546I significantly inhibited tumor growth (P < 0.001) and prolonged the survival of tumor-bearing mice (P < 0.01). Conclusion: The neoantigen peptide Glud1-V546I from mouse CT26 cells demonstrates effective anti-tumor responses in tumor-bearing mice, suggesting the potential for developing neoantigen-based personalized immunotherapies in CRC.