The Development of Antimicrobial α‐AApeptides that Suppress Proinflammatory Immune Responses

Herein we describe the development of a new class of antimicrobial and anti‐inflammatory peptidomimetics: cyclic lipo‐α‐AApeptides. They have potent and broad‐spectrum antibacterial activity against a range of clinically relevant pathogens, including both multidrug‐resistant Gram‐positive and Gram‐negative bacteria. Fluorescence microscopy suggests that cyclic lipo‐α‐AApeptides kill bacteria by disrupting bacterial membranes, possibly through a mechanism similar to that of cationic host‐defense peptides (HDPs). Furthermore, the cyclic lipo‐α‐AApeptide can mimic cationic host‐defense peptides by antagonizing Toll‐like receptor 4 (TLR4) signaling responses and suppressing proinflammatory cytokines such as tumor necrosis factor‐α (TNF‐α). Our results suggest that by mimicking HDPs, cyclic lipo‐α‐AApeptides could emerge as a new class of antibiotic agents that directly kill bacteria, as well as novel antiinflammatory agents that act through immunomodulation.