Project Summary The control of highly antimicrobial resistant (AMR) infections like multi-drug resistant Pseudomonas aeruginosa is a serious global public health concern. Multi-drug resistant P. aeruginosa are one of the top AMR micro- organisms, presenting a major challenge for infection control. Alternative interventions to traditional antimicrobials are urgently needed. Monoclonal antibodies (mAbs) targeting highly conserved proteins represent an important approach against infectious diseases. MAbs can be delivered immediately prior to hospitalization or a medical procedure to prevent or control infection. However, protein mAb delivery technology is severely limited by high manufacturing costs, slow development and long-term production, and a requirement for several high-dose administrations (mg/kg). These limitations tend to make protein mAb delivery a challenge for general administration and restrict its administration to limited populations. Our team has developed DMAb technology, a transformative approach that addresses these critical issues through encoding mAb genes into an optimized DNA platform that is administered directly in vivo. DMAbs reach protective levels in vivo with direct antimicrobial activity rapidly, can be manufactured simply and quickly, can likely avoid cold chain requirements, and are highly cost-effective compared to protein IgG. In a recent study, we demonstrated that engineered DMAbs can effectively deliver mAb in vivo to control MDR P. aeruginosa infection in mice (Patel, DiGiandomenico et al Nat. Comm. 2017). Our goal is to build on this work, through further enhancement in DMAb technology and to translate this approach into a strategy for control of antibiotic resistant infections. We are proposing to enhance the properties of our well-characterized DMAb lead-series directed against MDR P. aeruginosa and to develop more potent forms with enhanced antigen binding and receptor engagement to control infection. In this proposal, we will perform important studies to support translation of this approach to larger animals and ultimately to move to IND submission.