mRNA mediated expression of novel fusion phage tail protein with antimicrobial peptides inside macrophages for targeted clearance of intracellular <i>Mycobacterium tuberculosis</i>

Current anti-tuberculosis treatments primarily target extracellular <i>Mycobacterium tuberculosis</i> (<i>Mtb</i>), but exhibit limited efficacy against intracellular <i>Mtb</i>, leading to incomplete clearance of pathogens and an increased risk of recurrence. Antimicrobial peptides (AMPs) possess broad-spectrum antimicrobial activity and low potential for resistance development. Here we developed an <i>in vitro</i> mRNA expression platform which not only facilitates intracellular AMPs expression within macrophages, but also significantly enhances their bactericidal activity against <i>Mtb</i> post-infection. Notably, the combination of AMPs trimers demonstrated superior anti-<i>Mtb</i> activity compared to individual AMPs or other combinations. Furthermore, fusion of this AMP complex with either the minor tail protein Gp6 or lysin Gp10 from <i>Mycobacterium phage</i> L5 substantially improved macrophage-specific targeting and intracellular <i>Mtb</i> elimination. Thus, our current study provides novel insights and innovative strategies for the treatment of tuberculosis or other intracellular bacterial pathogens.