C-di-AMP inhibition-propelled unlocking bacterial cuproptosis accelerates tissue remodeling and confers long-lasting immunoprotection.

Abstract

Bacterial infections pose a major global health threat, with traditional antibiotics often failing due to drug resistance and recurrent infections. This study proposes a metal-phenolic therapeutic strategy that concurrently targets bacterial cyclic di-adenosine monophosphate (c-di-AMP) synthase and leverages copper ion delivery to eradicate infections and prevent recurrence. Through structure-based virtual screening and in vitro validation, theaflavin 3,3'-digallate (TF3) was identified as a natural c-di-AMP synthase inhibitor, which was then integrated into a copper-based metal-phenolic network to yield TF3-Cu nanoparticles (TF3-Cu NPs). This system exhibits stimuli-responsive drug release in acidic biofilm microenvironments, synchronously inhibiting c-di-AMP synthesis and delivering copper ions. Transcriptomics analysis reveals that by disrupting c-di-AMP metabolism, TF3-Cu NPs impair bacterial cell wall/membrane functions, which induces intracellular copper accumulation. Intracellular copper overload disrupts the tricarboxylic acid cycle, triggering cuproptosis-like bacterial death while suppressing biofilm maturation. Notably, TF3-Cu NPs drive immunogenic bacterial death via cuproptosis, promote dendritic cell maturation and expands the memory B cell compartment, thereby conferring durable protection against Staphylococcus aureus reinfection. Overall, this study validates c-di-AMP synthase as a promising antibacterial target and establish a dual-mechanism, antibiotic-free material approach, which couples c-di-AMP pathway inhibition with bacterial cuproptosis induction to simultaneously suppress biofilms and potentiate host immunity.