An OmpX mRNA-LNP vaccine induces protective humoral and cellular immunity against Klebsiella pneumoniae in a C57BL/6 mouse model

OmpX-Fc mRNA-LNP vaccination in C57BL/6 mice induces OmpX-specific antibodies and complete protection against lethal Klebsiella pneumoniae challenge, achieving 100% survival.

• Why it matters: Klebsiella pneumoniae threatens public health and antibiotic resistance makes prevention urgent, yet no KP vaccine is licensed and OmpX-targeting mRNA-LNP delivery remains largely untested.
• What they did: The study used immunoinformatics (including C-ImmSim) to assess OmpX antigen features, then immunized mice with OmpX-Fc mRNA-LNPs and measured humoral and cellular responses plus complement-mediated KP lysis.
• The result: OmpX-Fc mRNA-LNPs elevated IFN-{gamma} and IL-4 and produced significantly greater complement-mediated KP cell lysis than alum or luciferase controls, while reducing visceral bacterial burden after lethal challenge.