Sequential delivery of PD-1/PD-L1 blockade peptide and IDO inhibitor for immunosuppressive microenvironment remodeling via an MMP-2 responsive dual-targeting liposome
Chuan Hu, Yujun Song, Yiwei Zhang, Siqin He, Xueying Liu, Xiaotong Yang, Tao Gong, Yuan Huang, Huile Gao
Abstract
Intelligent responsive drug delivery system opens up new avenues for realizing safer and more effective combination immunotherapy. Herein, a kind of tumor cascade-targeted responsive liposome (NLG919@Lip-pep1) is developed by conjugating polypeptide inhibitor of PD-1 signal pathway (AUNP-12), which is also a targeted peptide that conjugated with liposome carrier through matrix metalloproteinase-2 (MMP-2) cleavable peptide (GPLGVRGD). This targeted liposome is prepared through a mature preparation process, and indoleamine-2,3-dioxygenase (IDO) inhibitor NLG919 was encapsulated into it. Moreover, mediated by the enhanced permeability and retention effect (EPR effect) and AUNP-12, NLG919@Lip-pep1 first targets the cells that highly express PD-L1 in tumor tissues. At the same time, the over-expressed MMP-2 in the tumor site triggers the dissociation of AUNP-12, thus realizing the precise block of PD-1 signal pathway, and restoring the activity of T cells. The exposure of secondary targeting module II VRGDC-NLG919@Lip mediated tumor cells targeting, and further relieved the immunosuppressive microenvironment. Overall, this study offers a potentially appealing paradigm of a high efficiency, low toxicity, and simple intelligent responsive drug delivery system for targeted drug delivery in breast cancer, which can effectively rescue and activate the body's anti-tumor immune response and furthermore achieve effective treatment of metastatic breast cancer.