Development of a novel method of enhancing the immunogenicity of malignant melanoma cells using the anaerobic site-accumulation properties of bacteria.

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K08333
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 53050:Dermatology-related
• Research Institution: Saitama Medical University
• Principal Investigator: Horiuchi Yutaka 埼玉医科大学, 医学部, 講師 (30608906)
• Co-Investigator(Kenkyū-buntansha): 村上 孝 埼玉医科大学, 医学部, 教授 (00326852)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 細菌 / 細胞内感染 / 悪性黒色腫

Outline of Final Research Achievements

We investigated whether bacterial intracellular infection could enhance adjuvant properties in cancer cells, triggering tumor-specific immune responses. The results were promising. Subcutaneous inoculation of mice with a mixture of tumour-forming non-infected and bacterial-infected cells not only suppressed tumourigenicity but also prevented tumour formation upon re-immunisation with only non-infected cells. Additionally, in vivo proliferation of tumor cell-derived antigen-specific CD8+ T lymphocytes (CTL) was observed in mice inoculated with infected cells. These findings hint at the potential of bacterial intracellular infection to revolutionize cancer immunotherapy by stimulating an anti-tumor immune response.

Free Research Field

腫瘍免疫学

Academic Significance and Societal Importance of the Research Achievements

本研究では、細菌細胞内感染ががん細胞におけるアジュバント特性を増強し、腫瘍特異的免疫応答を誘発するかどうか検討し、有望な結果を得た。今回得られた知見は、細菌の腫瘍細胞内感染を起点として抗腫瘍免疫応答が惹起されることを示しており、細菌を用いたがん治療法の科学的根拠を高めるものである。近年大きく発展を遂げた免疫チェックポイント阻害療法などとがん細菌療法の併用によって、従来までの標準的ながん治療の効果をより高めることができると考えられる。