| Title: |
Characterization of mAbs against Klebsiella pneumoniae type 3 fimbriae isolated in a target-independent phage display campaign |
| Authors: |
Grant, Andrew; Berry, Sophia; Rust, Steven; Irving, Lorraine; Bartholdson Scott, Josefin; Weinert, Lucy; Dougan, Gordon; Christie, Graham; Warrener, Paul; Minter, Ralph |
| Publisher Information: |
American Society for Microbiology; Department of Veterinary Medicine; //doi.org/10.1128/spectrum.00400-24 |
| Publication Year: |
2024 |
| Collection: |
Apollo - University of Cambridge Repository |
| Subject Terms: |
Klebsiella pneumoniae; MrkA; monoclonal antibody; scFv; type 3 fimbriae; Antibodies; Monoclonal; Klebsiella Infections; Animals; Fimbriae; Bacterial; Fimbriae Proteins; Mice; Humans; Macrophages; Phagocytosis; Cell Surface Display Techniques; Peptide Library; Adhesins |
| Description: |
We used phage display, antibody engineering and high-throughput assays, to identify antibody-accessible targets of Klebsiella pneumoniae. We report the discovery of mAbs binding to type 3 fimbrial proteins, including MrkA. We found that anti-MrkA mAbs were cross-reactive to a diverse panel of K. pneumoniae clinical isolates, representing different O-serotypes. mAbs binding to MrkA have previously been described and have been shown to provide prophylactic protection although only modest protection when dosed therapeutically in vivo in a murine lung-infection model. Here, we used a combination of binding and opsonophagocytic killing studies using a high-content imaging platform to provide a possible explanation for the modest therapeutic efficacy in vivo reported in that model. Our work shows that expression of K. pneumoniae type 3 fimbriae in in vitro culture is not homogenous within a bacterial population. Instead, sub-populations of bacteria that do, and do not, express type 3 fimbriae exist. In a high-content opsonophagocytic killing assay, we showed that MrkA targeting antibodies initially promote killing by macrophages, however over time this effect is diminished. We hypothesise the reason for this is that bacteria not expressing MrkA can evade opsonophagocytosis. Our data support the fact that MrkA is a conserved, immunodominant protein that is antibody accessible on the surface of K. pneumoniae and suggest that additional studies should evaluate the potential of using anti-MrkA antibodies in different stages of K. pneumoniae infection (different sites in the body) as well as against K. pneumoniae biofilms in the body during infection and associated with medical devices. ; This work was funded by AstraZeneca and the Cambridge Biomedical Research Centre. SKB was funded by a Cambridge AstraZeneca PhD studentship. The authors are grateful for the assistance of AstraZeneca scientists John Ferguson and Augustin Harvey for the preparation of monocyte-derived macrophages. The authors thank University of ... |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
English |
| Relation: |
https://www.repository.cam.ac.uk/handle/1810/369791 |
| Availability: |
https://www.repository.cam.ac.uk/handle/1810/369791 |
| Rights: |
Attribution 4.0 International ; https://creativecommons.org/licenses/by/4.0/ |
| Accession Number: |
edsbas.8AFB9E19 |
| Database: |
BASE |