# An intranasal room stable vaccine formulation to prevent Pseudomonas aeruginosa  (R21AI169691)

> **NIH NIH R21** · UNIVERSITY OF MISSOURI-COLUMBIA · 2024 · $193,930

## Abstract

PROJECT SUMMARY
 Vaccination is perhaps the greatest public health achievement of our time. With an explosion of antibiotic
resistance, developing new vaccines against multi-drug resistant (MDR) bacterial pathogens is more
important than ever. Pseudomonas aeruginosa (Pa) is an important opportunistic human pathogen that
causes severe infections in patients with cystic fibrosis (CF), burns, severe wounds, pneumonia, as well as
critically ill patients who require intubation or catheterization. Clearing Pa has become problematic as it has
become increasingly antibiotic resistant. This is exacerbated by the fact that the biggest risk factor for negative
outcomes associated with MDR Pa is advanced age. After the age of 60, there is a significant increase in
morbidity and mortality resulting from MDR Pa. While there are Pa vaccines in development, none are
licensed. The goal of the R21 is to define a stable nanoparticle (NP) suspension for our prophylactic
Pa vaccine that prevents Pa, regardless of strain, prior to establishment of a biofilm.
 Like many Gram-negative pathogens, Pa strains of the PAO1/PA14-clades possess a type III secretion
system (T3SS) that allows avoidance of host innate immunity and is required for initiating infection.
Structurally resembling a molecular syringe with an external needle, the T3SS apparatus (T3SA) provides an
energized conduit from the bacterium into the host cell for transporting the effector proteins that mediate key
aspects of infection. A needle tip protein and the first of two translocator proteins localize to the distal end of
the T3SA needle to mediate host cell contact. In Pa these proteins are PcrV and PopB, respectively, and they
are required for pathogenesis. They are also highly conserved (95-98%) among all P. aeruginosa strains that
possess a T3SS. We have fused PcrV and PopB to give PaF. To promote simultaneous uptake of antigen
and adjuvant by antigen presenting cells, we genetically fused LTA1, the active moiety of dmLT, to the N-
terminus of PaF (L-PaF). L-PaF reduces mouse and rat lung Pa burden significantly when challenged with a
PAO1/PA14 clade Pa. Recently, Pa outliers of the PAO7 clade have been identified that are devoid of the
T3SS and instead use exolysin A (ExlA) to disrupt host cell membranes. We have added ExlA to our L-PaF
formulation and, when delivered intranasally, have demonstrated protection against PAO1/14 and PAO7
clades in mice. Sera from these mice exhibit significant opsonophagocytic killing (OPK). Additionally, elevated
levels of IL-17 were secreted from lung cells of L-PaF-vaccinated mice. Both IL-17 and OPK are deemed
important in clearing Pa infections.
 In this R21, we will assess the protective immune response of a stable particulate ExlA/L-PaF NP
suspension. We will complete this project in two aims: 1) We will generate nanoparticle formulations for the
ExlA/L-PaF antigens and assess their stability. 2) We will then determine the immune response(s) elicited by
the ExlA/...

## Key facts

- **NIH application ID:** 10918223
- **Project number:** 5R21AI169691-02
- **Recipient organization:** UNIVERSITY OF MISSOURI-COLUMBIA
- **Principal Investigator:** Wendy L. Picking
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $193,930
- **Award type:** 5
- **Project period:** 2023-09-01 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10918223

## Citation

> US National Institutes of Health, RePORTER application 10918223, An intranasal room stable vaccine formulation to prevent Pseudomonas aeruginosa  (R21AI169691) (5R21AI169691-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10918223. Licensed CC0.

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