Persistent Membrane-Anchored Oligomeric Peptides with Nanopore Formation for Targeted Immune Modulation.

Abstract

In the field of targeted diagnosis and therapy, one of the key challenges is the off-target effect of these recognition molecules. Herein, a new class of oligomeric helical peptides is introduced through rational design and high-throughput screening to address this challenge. Following amino acid mutations and structural optimizations, lead candidates TA03 and TA10 were identified. Thereinto, TA03 was shown to specifically recognize the PD-L1 target and employ a unique aromatic side-chain anchoring strategy to form stable nanopores on the tumor cell membrane, ensuring prolonged residence time. This structure from the precise match between helix length and lipid bilayer thickness, alongside the positioning of two tryptophan (Trp) residues near the peptide terminus. Both Trp side chains interact with the phospholipid membrane via aromatic-hydrophobic forces, allowing TA03 to form an "hourglass-like" pore structure. This design ensures proper membrane localization and extends residence time on tumor cells of TA03, increasing the persistent interactions between TA03 and PD-L1, effectively avoiding off-target effects. Furthermore, the unique structure and PD-L1 targeting of TA03 cause physical disruption to tumor cells boosting immunotherapy effects and inhibiting tumor growth. It provides an avenue for new molecular structure to overcome off-target effect towards the membrane associate targets.