Work Package 1: Drug discovery and translational research

Main partners:

  • Fredrik Björkling, SUND, Department of Drug Design and Pharmacology (ILF) (WP leader)
  • Luca Guardabassi, SUND, Department of Veterinary Disease Biology (IVS)
  • Peter E. Nielsen, SUND, Department of Cellular and Molecular Medicine (ICMM)
  • Anders Løbner-Olesen, SCIENCE, Department of Biology (BI)

External collaborators:

  • Stefano Donadio (Naicons)
  • Hee-Jeon Hong (University of Cambridge)
  • Jeffrey Watts (Zoetis)
  • Niels Frimodt-Møller (Hvidovre Hospital),
  • Karen Angeliki Krogfelt (Statens Serum Institut)

Main objectives:

  1. Identification of targets for antibiotic-potentiating compounds (helper drugs)
  2. Identification of targets for horizontal gene transfer (HGT) inhibitors
  3. Selection and optimization of new peptide-based drug leads

Task 1.1. Reversal of antibiotic resistance by helper drugs
Scientist in charge: Post Doc (IVS)

The aim is to identify genes that can be targeted by helper drugs to counteract resistance towards existing antibiotics. Genes up-regulated in multidrug-resistant bacteria exposed to antibiotic therapeutic concentrations will be identified using a combined transcriptomic and proteomic approach. The hypothesis that antibiotic susceptibility can be restored by inhibiting expression of these genes will be validated by knock-out mutagenesis and antisense technology. For selected target genes/proteins, we will establish genetic screens for inhibition such as inhibition of promoter activity, enzyme activity, protein-protein interactions, etc. Helper drugs able to reduce the minimum inhibitory concentration (MIC) of the tested antibiotic by altering the function of the target gene/protein will be identified by screening chemical and combinatorial peptide libraries provided by the industrial partners and ourselves, respectively.

Task 1.2. Identification of horizontal gene transfer (HGT) inhibitors

Scientist in charge: Marco Minoia (IVS)

The hypothesis is that transfer of resistance genes in the gut microbiota during therapy can be inhibited by inclusion of HGT inhibitors in antibiotic drug formulations. We will validate this approach by inhibiting transfer ESBL-encoding plasmids during therapy with cephalosporins, as an extension of recent work at IVS showing that some cephalosporins modulate conjugation of ESBL-encoding plasmids. Transfer genes and/or gene products that are up- or down-regulated during therapy will be identified, and the effect of altered expression of these genes on conjugation frequencies determined. Finally, HGT inhibitors for selected genes/proteins will be identified as described for Task 1.1 and their efficacy in reducing conjugation frequencies will be validated in vitro and in vivo to generate a proof of concept.

Task 1.3. Novel antimicrobial peptide and antisense based antibiotics
Scientist in charge: Henrik Franzyk (ILF)

Antimicrobial peptides, peptidomimetics and antisense peptide nucleic acids (PNA) exploit mechanisms of action not affected by (most) existing antibiotic resistance, but pose efficacy and systemic toxicity challenges. Based on our previous structure-activity studies, we aim at designing drug leads with highly reduced toxicity. Functionalized AMPs and peptidomimetics will be used as targeting ligands on the surface of antibiotic nanoparticle formulations to improve bioavailability. Also, antisense PNA-peptide conjugates targeting essential bacterial genes, and that show potent batericidal activity will be optimized. Finally, novel antisense PNA-peptides inhibiting biofilm formation by knocking down quorum sensing genes shall be studied as helper drugs in in vivo mouse lung infection models.

Task 1.4. In vivo testing of selected lead candidates

Scientist in charge: Post Doc (IVS)

The efficacy of lead drug candidates will be evaluated by using murine and porcine infection models. The endpoint variables will include acute phase reactant and cytokine profiling (transcriptomics and proteomics in respiratory and urinary tissue, and blood), qualitative and quantitative (stereology) pathology and microbiology. In addition to well-established mouse models, a porcine A. pleuropneumoniae respiratory infection model will be used for testing novel antimicrobial compounds (WP1), vaccines (WP2) and drug delivery systems (WP3) as well as for discovery of new diagnostic markers (WP4).