Bifunctional Phagocytic Synapse Enhancers for Cancer Immunotherapy

Abstract

Immunotherapy profoundly impacted cancer treatments by harnessing the patients immune system. Phagocytosis, the process whereby immune cells engulf and destroy foreign particles or cells, plays a critical role in tumour cell clearance. Herein, we introduce a novel concept termed "ENPHASYS" - Enhancement of Phagocytic Synapses - designed to direct and amplify phagocytosis of cancer cells using heterobifunctional molecules named phagocytic synapse enhancers (PSEs). By engineering a de novo PD-L1 binder linked to a natural phagocytosis promoting peptide, tuftsin, the resulting PSE combines PD-L1 blockade with enhanced tumour cell phagocytosis; in addition, the PSEs induce macrophages to internalize a membrane or extracellular target. Intratumoural treatment of colorectal carcinoma- or glioblastoma-burdened immunocompetent animals resulted in beneficial overall survival, delayed tumour growth and a potent antitumor response driven by T-cell activation and TAM reprogramming, underpinning the translational relevance of ENPHASYS. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=118 SRC="FIGDIR/small/642658v1_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@1673fd4org.highwire.dtl.DTLVardef@18fa319org.highwire.dtl.DTLVardef@11cf680org.highwire.dtl.DTLVardef@7b8784_HPS_FORMAT_FIGEXP M_FIG C_FIG