In vivo imaging of immune and inflammatory responses during cancer photoimmunotherapy

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20706
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0801:Pharmaceutical sciences and related fields
• Research Institution: Hokkaido University
• Principal Investigator: Nakajima Kohei 北海道大学, 薬学研究院, 助教 (40907771)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 光免疫療法 / がん / 生体イメージング

Outline of Final Research Achievements

The purpose of this study is to elucidate the process of immune and inflammatory responses induced by near-infrared photoimmunotherapy (PIT), which is a newly developed cancer phototherapy, using in vivo imaging techniques. We performed PIT on tumor-bearing nude mice and analyzed them using [18F]FDG-PET and MRI. The results suggested that PIT induced inflammatory edema in surrounding tissue of the light-irradiated tumors. Furthermore, when PIT was performed on immunocompetent C57BL/6J mice, more significant changes in blood electrolytes was observed compared to nude mice. These results suggested inflammatory and/or immune cells such as T cells are considered to be deeply related to the physiological response during PIT.

Free Research Field

がん治療・イメージング

Academic Significance and Societal Importance of the Research Achievements

本研究において、PITが引き起こす免疫・炎症反応の一端を明らかにすることに成功した。がん治療において、過剰な免疫・炎症応答は副作用に繋がる可能性がある一方、適切に免疫応答が活性化された場合は、抗腫瘍免疫応答の誘導を介して高い治療効果が得られる可能性も考えられる。したがって、本研究を足掛かりに引き続き検討を行うことで、臨床において副作用を回避しつつ効果的な治療を行うための方策につながることが期待される。