Biomimetic neutrophil nanotoxoids elicit potent immunity against Acinetobacter baumannii in multiple models of infection

Summary

This preclinical vaccine study uses neutrophil-membrane-coated nanoparticles to capture secreted factors from multidrug-resistant Acinetobacter baumannii. Because neutrophils are early responders during infection, their membrane provides a biologically relevant decoy surface for binding virulence products that would otherwise be too dangerous to administer as antigens. The resulting nanotoxoid safely presents multiple captured factors for antivirulence vaccination. Immunization rapidly mobilized innate immune cells and also promoted pathogen-specific adaptive responses. The vaccine was tested in mouse models representing pneumonia, bloodstream infection, and a superficial wound. Across these routes, vaccinated animals showed significant protection, including improved survival, reduced signs of acute inflammation, and lower bacterial burdens. The principal finding is that one neutrophil-derived nanotoxoid can generate multivalent immunity with activity across three distinct manifestations of A. baumannii infection. This is important for a hospital pathogen that lacks an approved vaccine and causes varied disease. The abstract does not identify the captured antigens, establish strain breadth or immune durability, compare other vaccines or antibiotics, quantify adverse effects, or demonstrate protection in immunocompromised hosts or humans.