Nanoparticle-mediated celastrol ER targeting delivery amplify immunogenic cell death in melanoma

Abstract

Introduction

Chemoimmunotherapy, which benefits from the combination of chemotherapy and immunotherapy, has emerged as a promising strategy in cancer treatment. However, effectively inducing a robust immune response remains challenging due to the limited responsiveness across patients. Endoplasmic reticulum (ER) stress is essential for activating intracellular signaling pathways associated with immunogenic cell death (ICD), targeting drugs to ER might enhance ER stress and improve ICD-related immunotherapy.

Objectives

To improve the immune response of Chemoimmunotherapy.

Methods

ER targeting nanoparticles TSE-CEL/NP were constructed to enhance immunogenic cancer cell death. Flow cytometry, confocal microscope, TEM and immunofluorescence were used to evaluate the ER targeting effect and immunogenic tumor cell death in vitro on B16F10 tumor cells. Unilateral and bilateral tumor models were constructed to investigate the efficacy of anti-tumor and immunotherapy in vivo. Lung metastasis B16F10 melanoma tumor-bearing mice were used to assess the anti-metastasis efficacy.

Results

TSE-CEL/NP could specially accumulate in ER, thereby induce ER stress. High ER stress trigger the exposure of CRT, the extracellular release of HMGB1 and ATP. These danger signals subsequently promote the recruitment and maturation of dendritic cells (DCs), which in turn increase the proliferation of cytotoxic T lymphocytes (CD8⁺ T cells), ultimately resulted in an improved immunotherapy efficacy against melanoma. In vivo experiments showed that TSE-CEL/NP exhibits excellent antitumor efficacy and triggers a strong immune response.

Conclusion

Our findings demonstrated that celastrol ER targeting delivery could amplify immunogenic cell death in melanoma, which provide experimental basis for melanoma immunotherapy.