Bacterial infections are now a global threat demanding novel treatments due to the appearance of resistances against antibiotics at a high pace. The ESKAPE pathogens are those with highest importance in the EU and chronic infections due to biofilm formation are a particular task. Noninvasive pathogen-specific imaging of the infected tissue is not clinically available. Its successful implementation will enable the choice of appropriate therapy and boost efficacy. Furthermore, Gram-negative bacteria have a highly protective cellular envelope as an important resistance mechanism for drugs acting intracellularly, resulting in an alarmingly empty drug-pipeline. To overcome this gap, I will establish Lectin-directed Theranostics targeting pathogens via their extracellular carbohydrate-binding proteins at the site of infection for specific imaging and treatment. This will be implemented for the highly resistant ESKAPE pathogen Pseudomonas aeruginosa through 3 different work packages. WP1 Sweet Imaging: Design & conjugation of lectin-directed ligands to imaging probes, Optimization of ligand/linker, in vivo proof-of-concept imaging study. WP2 Sweet Targeting: Delivery of antibiotics to the infection through covalent linking of lectindirecting groups. Employing different antibiotics, assessment of bactericidal potency and targeting efficiency. Manufacturing of nano-carriers with surface exposed lectin-directed ligands, noncovalent charging with antibiotics. In vitro and in vivo targeting. WP3 Sweet SMART Targeting: Conjugates as SMART drugs: specific release of anti-biofilm lectin inhibitor and drug cargo upon contact with pathogen, development of linkers cleavable by pathogenic enzymes. SWEETBULLETS will establish fundamentally novel lectin-directed theranostics to fight these deleterious infections and provide relief to nosocomially infected and cystic fibrosis patients. It is rapidly extendable towards other ESKAPE pathogens, e.g. Klebsiella spp..

The bacterial sliding clamp (DnaN) is an innovative target for the development of novel antibiotics, which are urgently needed to overcome the alarming antimicrobial resistance crisis. In the previous ERC starting grant (NovAnI), we discovered a novel DnaN inhibitor (WAM-N17) with promising broad-spectrum antibacterial activity including multidrug-resistant (MDR) pathogens. In this PoC project, we will optimize the antibacterial potency and spectrum and characterize the in vivo pharmacokinetic (PK) and pharmacodynamic (PD) properties of the WAM-N17 class so as to develop preclinical lead candidates for the treatment of bacterial infections, especially those caused by MDR germs. To achieve this goal, we will pursue three main activities. (i) Design and synthesis of 25–30 compounds (in two rounds) with modifications focusing on improving the anti-Gram-negative activity as well as target identification through chemical probes to further validate DnaN and identify other potential targets in bacteria. (ii) Evaluation of antibacterial activity, target binding/inhibition, and in vitro ADME-T (absorption, distribution, metabolism, excretion, toxicity) characterization for all new compounds. The frontrunners will be profiled for antibacterial activity against an extended panel of Gram-negative and MDR clinical isolates and subjected to mode of action (MoA) and target-identification studies. The most promising ten compounds will be submitted for in vivo PK studies and the best two lead candidates will be tested in a proof-of-concept in vivo efficacy study using relevant infection mouse models. (iii) Ultimately, we will file a patent to secure our intellectual property rights and continue to move this class of compounds forward into preclinical and then clinical studies in collaboration with a pharmaceutical industry partner. The knowledge that will be gained from this PoC project is essential to develop an urgently needed new antibiotic with an unprecedented mode of action.

The emergence of multi-drug resistant pathogens is a serious global problem. In this alarming situation, novel targets for which inhibitors with an unprecedented mode of action can be developed are urgently required. This proposal aims at the development of selective and potent inhibitors of the important and underexplored anti-infective target DXS, an enzyme from the 2C-methyl-D-erythritol 4-phosphate pathway that is entirely absent in humans but is essential for medically relevant pathogens (e.g., Plasmodium falciparum, Mycobacterium tuberculosis, Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus). Despite substantial efforts dedicated to the discovery of inhibitors for DXS, to date very few active compounds have been reported and none of them fulfil the requirements as an ideal candidate for further development. To address these issues and maximise the chances of success, we will use dynamic combinatorial chemistry (DCC) as a hit identification strategy for the first time for the enzyme-DXS. To explore hitherto unexplored parts of the chemical space, we will pioneer the use of chiral heterocyclic building blocks in DCC for the discovery of potent inhibitors of the enzyme DXS. Use of chiral heterocycles in DCC will allow to rapidly access novel scaffolds. These chiral heterocyclic scaffolds will be evaluated for their biochemical activity on bacterial DXS. The most promising candidates will be tested in in vivo cell-based assays in bacteria. The proposed approach for the design of chiral heterocyclic inhibitors for novel targets such as the enzyme DXS will enhance the knowledge about this underexplored target and will open up access to various potent inhibitors. Hence, this research programme will greatly improve the chances of idnetifiying new anti-infective agents with a novel mode of action, leading to socio-economical benefits for the health care sector in the European Union and also globally.

Influenza is a significant public health threat and vaccines are crucial for preventing infections at population-level. The efficacy of vaccination per individual, however, is highly variable. The causes for this broad variability in vaccine response between individuals remain poorly understood. In this proposal, I hypothesize that genetic variants and their downstream pathways underlie the heterogeneity in vaccine response between individuals. This ERC project aims to for the first time, systematically investigate the interactions between genetic, non-genetic host and environmental factors, and the response to vaccination in order to build reliable models for predicting vaccine efficacy. The outcomes of this research will pinpoint key deterministic factors and identify modulators that can be used to improve vaccination strategies. This project is based on the expertise that my research group has built up for identifying the downstream consequences of genetic variants, and for predictive modelling through integration of large cross-omics datasets. Given the rapid evolution of influenza virus, I will use seasonal trivalent inactivated influenza vaccines as prototype responses within two cohorts of 500 individuals from the Netherlands and 200 individuals from Germany. I will systematically generate, analyse, and integrate the cross-omics data (six layers of information from genome, epigenome, transcriptome, proteome, metabolome, and microbiome) with immune phenotypes (e.g. antibody titers, an important indicator of protection) using novel computational methods. This research will reveal the previously unknown cell-types, molecules, and pathways involved in vaccine-induced immune response and provide mathematical models for predicting individual variation in immune response, a crucial first step towards personalized prevention. The key molecules I identify will provide leads for pharmacological modulators for improving vaccine efficacy.