JRHDD – Joint Research Hub for Drug Discovery and Delivery

Drug design and selection

Discovery of novel agonists and antagonists of innate immune receptors (pattern recognition receptors, PRRs) or the molecules downstream in the signaling pathway related to the indicated diseases will be performed as previously described [1] using computational methods by our partner, Hebrew University. For example, for TLRs that have a published set of small molecule agonists/antagonist, models are based on physical and chemical properties of ligands and will serve as filters for scoring and picking top candidates from huge (millions) numbers of commercially available molecules. Modeling and docking is performed in iterations, building on experimental screening results [1, 3]. A library of 200–300 compounds is defined initially and smaller libraries are employed for subsequent screenings for each newly addressed PRR or group of PRRs [1]. E.g. ten TLR9 antagonists effective in nanomolecular concentrations have already been verified.

Targeted delivery systems

Liposomes (NP) are potent drug delivery systems that protect the drug from degradation, improve its pharmacokinetic properties and deliver a relatively high drug payload. For efficient NP accumulation at the target site, both long circulation time and efficient particle targeting are critical. True molecular targeting of liposomes can be achieved through ligand linkage to appropriately designed ‘stealth’ NP by our partners [2]. Targeting will be designed specifically to the indications mentioned above.

In vitro and in vivo test systems

Infection models are available for both fungal and viral infections at Fraunhofer IGB [4-6]. These models are used to validate the new immune-modulating compounds as well as the formulations. In a first step, we use cell-based assays [3] to validate the PRR-modulating activity of the compounds identified in silico experimentally (as mentioned above); second, we use complex 3D-tissue models, including components of the immune system [4] to validate both the effect of the IMC on different cell types including immune cells and the formulation in delivering the compounds appropriately. Animal models for further validation of the lead compounds of these indications are available with our partners.

Summary

With this approach, we aim to combine two central ideas supporting the healing processes in infection and inflammatory diseases: (i) modulating innate immunity by supporting clearance of invading pathogens or ameliorating the (auto)inflammatory process and (ii) targeted delivery of known and novel drugs to infected or pathologically-modified tissues/cells.

1. Zatsepin, M.; Mattes, A.; Rupp, S.; Finkelmeier, D.; Basu, A.; Burger-Kentischer, A.; Goldblum, A. (2016) Computational Discovery and Experimental Confirmation of TLR9 Receptor Antagonist Leads. J Chem Inf Model 56: 1835-1846
2. Ron-Doitch, S.; Sawodny, B.; Kühbacher, A.; David, M. M.; Samanta, A.; Phopase, J.; Burger-Kentischer, A.; Griffith, M.; Golomb, G.; Rupp, S. (2016) Reduced cytotoxicity and enhanced bioactivity of cationic antimicrobial peptides liposomes in cell cultures and 3D epidermis model against HSV. J Control Release 229: 163-171
3. Burger-Kentischer, A.; Abele, I. S.; Finkelmeier, D.; Wiesmuller, K. H.; Rupp, S. (2010) A new cell-based innate immune receptor assay for the examination of receptor activity, ligand specificity, signalling pathways and the detection of pyrogens. Journal of immunological methods 358: 93-103
4. Kühbacher, A.; Sohn, K.; Burger-Kentischer, A.;Rupp, S. (2017) Immune cell-supplemented human skin model for studying fungal infections. Methods in molecular biology 1508: 439-449
5. Hogk, I.; Rupp, S.; Burger-Kentischer, A. (2013) 3D-tissue model for herpes simplex virus-1 infections. Methods in molecular biology 1064; 239-251
6. Hogk, I.; Kaufmann, M.; Finkelmeier, D.; Rupp, S.; Burger-Kentischer, A. (2013) An in vitro HSV-1 reactivation model containing quiescently infected PC12 cells. BioResearch open access 2: 250-257