Monoclonal Antibody to Combat Pseudomonas Aeruginosa
NIH
EMORY UNIVERSITY
PROJECT SUMMARY/ ABSTRACT. Pseudomonas aeruginosa is a Gram-negative, opportunistic pathogen that infects immunocompromised individuals, especially in the hospital setting. This bacterium is an important pathogen in people with weakened immune systems, injuries, and other underlying physiologic dysfunctions. P. aeruginosa is responsible for up to 20% of all hospital-acquired pneumonias. It is one of major causes of nosocomial infections and has been noted to be one of the most common bacteria co-infecting patients with COVID-19 or causing super-infections following COVID-19 infections. Despite improvements in antimicrobial therapy and hospital care, P. aeruginosa bacteremia and pneumonia remains fatal in about 30% of cases. P. aeruginosa is also the leading cause of chronic life-threatening lung infections in cystic fibrosis patients. This bacterium is naturally antibiotic resistant and infections are notoriously difficult to treat once established, with no vaccine available. We propose using the abundant and essential protein, elongation factor-Tu (EF-Tu), as an antibody target for P. aeruginosa. While best known for its role in protein synthesis, work from our group and others indicate that EF- Tu can be surface-exposed on P. aeruginosa. Our PRELIMINARY RESULTS show that P. aeruginosa EF-Tu is immunogenic in mice and protective in a murine model of acute P. aeruginosa pneumonia. We have generated a mouse monoclonal antibody to EF-Tu promotes partial clearance of P. aeruginosa in this model. This “Partnerships for the Development of Novel Therapeutics to Combat Select Antibiotic Resistant Bacteria and Fungi” (RFA-AI-22-028) and represents a collaborative effort between Dr. Joanna Goldberg at Emory University in Atlanta, GA (the PI), Dr. Vu Truong at Aridis Pharmaceuticals in Los Gatos, CA (industrial partner), Dr. Marion Pepper from the University of Washington, Seattle, WA and Dr. Sebastian Alberti from the University of Balearic Islands in Palma, Spain. Using spleens from mice we will immunize mice with EF-Tu using protocols optimized for protection and blood from humans that have high titers of antibodies to EF-Tu, we will obtain B- cells that will be screened at single cell level using flow cytometry and a nanoculture microfluidic array, respectively, to identify monoclonal antibodies specific for P. aeruginosa EF-Tu, followed by functional screens for binding and phagocytic killing of P. aeruginosa. We will also test these monoclonal antibodies for efficacy in mouse models of infection as an initial step toward future clinical studies. We believe the studies proposed here represent the appropriate first steps towards developing a new passive reagent that could be given to P. aeruginosa-infected patients regardless of the nature of the infecting strain and associated antibiotic-resistance profile, as well as the immune status of the patient. By the completion of this project, we will have generated and validated 10 murine-derived and 10 human-derived monoclonal antibodies to EF-Tu. Partnering with Aridis Pharmaceuticals for this project will keep us focused on our goal of developing these reagents for human use. PROJECT NARRATIVE. New approaches to fight Pseudomonas aeruginosa infections are desperately needed. We have already generated a monoclonal antibody to the conserved essential protein EF-Tu and shown it to be able to decrease colonization in a murine model of acute P. aeruginosa pneumonia. Here we will screen spleen cells from immunized mice and blood from humans with high titer antibodies to EF-Tu at single cell level using flow cytometry and an innovative nanoculture microfluidic array, respectively, to generate additional monoclonal antibodies to EF-Tu with even more efficacy based on in vitro binding assays, opsonophagocytic killing, and mouse challenge studies, as a first step to develop novel reagents to treat infections caused by this opportunistic pathogen.
Non-SBIR/STTR