Activating Innate Immunity by a STING Signal Amplifier for Local and Systemic Immunotherapy

作者：Song, Wen; Song, Shu-Jun; Kuang, Jing; Yang, Hang; Yu, Tao; Yang, Fan; Wan, Tao; Xu, Yi; Wei, Si-Tian; Li, Mu-Xuan; Xiong, Yuan^*; Zhou, Ying^*; Qiu, Wen-Xiu^*

来源：ACS Nano, 2022, 16(10): 15977-15993.

DOI：10.1021/acsnano.2c03509

• innate immunity
• STING
• mitochondria damage
• aPD-L1
• immunotherapy

The number of patients who benefit from acquired immunotherapy is limited. Stimulator of interferon genes (STING) signal activation is a significant component to enhance innate immunity, which has been used to realize broad-spectrum immunotherapy. Here, M@P@HA nanoparticles, as a STING signal amplifier, are constructed to enhance innate immunotherapy. Briefly, when M@P@HA was targeted into tumor cells, the nanoparticles decomposed with Mn2+ and activated the release of protoporphyrin (PpIX). Under light irradiation, the generated reactive oxygen species disrupt the cellular redox homeostasis to lead cytoplasm leakage of damaged mitochondrial double-stranded (ds) DNA, which is the initiator of the STING signal. Simultaneously, Mn2+ as the immunoregulator could significantly increase the activity of related protein of a STING signal, such as cyclic GMP-AMP synthase (cGAS) and STING, to further amplify the STING signal of tumor cells. Subsequently, the STING signal of tumor-associated macrophages (TAM) is also activated by capturing dsDNA and Mn2+ that escaped from tumor cells, so as to enhance innate immunity. It is found that, by amplifying the STING signal of tumor tissue, M@P@HA could not only activate innate immunity but also cascade to activate CD8(+) T cell infiltration even in a tumor with low immunogenicity.

• 单位
  上海交通大学; y; 华中科技大学