Project area D:

Project description:

Cleavage of viral envelope proteins by host proteases is essential for the infectivity of many human pathogenic viruses. Among others, the surface glycoproteins of highly pathogenic avian influenza viruses (e.g. H5N1), chikungunya virus or dengue, West Nile and Zika viruses are activated by furin-like serine proteases. The surface glycoproteins hemagglutinin of zoonotic H7N9 and seasonal influenza A viruses or the spike protein S of many coronaviruses (CoV) are cleaved by the membrane-bound trypsin-like serine protease TMPRSS2. Recently, we were able to show that SARS-CoV-2 S is activated by both furin and TMPRSS2. Therefore, these host proteases are promising targets for the development of novel broad-spectrum antiviral agents.

Crystal structure of furin in complex with inhibitor MI-1851

Crystal structure of TMPRSS2 superimposed with inhibitors MI-1904 (yellow) and MI-432 (orange).

Scientific goal:

Structure-based development of effective inhibitors targeting virus-activating host proteases; determination of their potency and selectivity by enzyme kinetic studies; structural characterization of their binding mode in complex with relevant host proteases; testing of their antiviral efficacy against significant human pathogenic viruses in cell cultures, tissue cultures and animal models.

DRUID Collaboration partners:

A1 Becker lab, A2 Grünweller lab, B6 Herker lab, C1 Hildt lab

References D1: 1. Böttcher et al. (2006) J Virol 80: 9896-8 3. Becker et al. (2012) J Biol Chem 287: 21992-03 4. Böttcher-Friebertshäuser et al. (2012) Vaccine 30: 7374-80 5. Ivanova et al. (2017) ChemMedChem 12: 1953-68 6. Lam van et al. (2019) ChemMedChem 14, 673-85 7. Bestle et al. (2020) LSA 3: e202000786  8. Bestle et al. (2021) J Virol 95: e0090621 9. Lam van et al. (2021) ACS Med Chem Lett 12: 426-32.

Project description:

HEV infects more than 20 Mio people per year  and concerns industrial nations as well as developing countries. At present there is no specific therapy available.As non-enveloped virus HEV release depends on endodomal processes which represent a promising target for antivirals. In the first funding period the lysosmal degradation of HEV in the endosomal system was identified as a central anchor point for antivirals. In addition to innate immunity cholesterol homeostasis is a a central factor affecting HEV reelase. Based on this the underlying mechanisms  are analysed in detalil to identifiy further targets  which can be addressed by drug repurposing. Animal models will help to broaden the insight in immunological processes controlling HEV life cycle.

3D reconstruction of subcellular distribution of HEV (green) , GBP-1 (cyan) and lysosomes (red) in interferon -treated cells.

CLSM-based 3D reconstruction of sub-cellular distribution of HEV (green) and lysosomes (cyan) after induction of and cholesterol accumulation (magenta).

Scientific goal:

Inhibtion of the endosomal life cycle of HEV by modulation of cholesterol-dependent regulated target structurs via application of identified bioactive compounds (drug repurposing).

DRUID Collaboration partners:

A2 Grünweller lab, A4 Heine/Reuter lab, B1 Diederich/Kolb lab, B6P Herker lab, C5 Glebe/Geyer lab, D1 Steinmetzer lab

References D2:  [1] Glitscher et al. (2018) Viruses 10(6):301; [2] Müller et al. (2020) Antiviral Res 174:104706; [3] Basic et al. (2019) Antiviral Res 172:104644; [4] Glitscher et al. (2021) J Virol doi: 10.1128/JVI.01564-20; [5] Glitscher et al. (2021) Cell Mol Gastroenterol Hepatol, doi:10.1016 /j.jcmgh.2021.02.002; [6] Himmelsbach et al. (2018) Emerg Microbes Infect 7(1):196. [7] Glitscher et al. (2021) Cell Microbiol. 16:e13379

Project description:

Leishmaniasis is a neglected tropical disease caused by the parasite Leishmania spp, which is endemic in almost 100 countries. We could demonstrate that apoptotic Leishmania major (L. major) promastigotes are both responsible for the infectivity and the survival of parasites in host cells. Apoptotic parasites induce an anti-inflammatory response in human macrophages that does not lead to an effective T-cell response against Leishmania. Even if L. major parasites show all typical characteristics of apoptosis, typical eukaryotic apoptosis regulating proteins are not present in Leishmania.

Staining of fragmented DNA (TUNEL staining) in L. major Cas9/T7 in which apoptosis was induced by Miltefosin (TUNEL: green; DAPI: blue; anti-Lm-serum: red. © Ger van Zandbergen)

Scientific goal:

For a novel vaccination approach and to kill parasites we aim to identify apoptosis regulating proteins in Leishmania as potential drug targets as well as attenuated Leishmania strains without anti-inflammatory properties.

DRUID Collaboration partners:

B1 Kolb, B3 Rahlfs/Kolb, E3 Rahlfs/Przyborski

References D3: [1] Arens et al. (2018) Front Immunol 31(9):1772. [2] Crauwels et al. (2019) Front Immunol 22(10):2697. Further publications within DRUID: [3] Turoňová et al. (2020) Science 370(6513):203-208.

Project description:

Cryptosporidium spp. are intestinal parasites which cause severe diarrhoea in humans, especially in HIV patients and young children. Especially in developing countries these protozoan infections induce high morbiditiy and mortality. So far, epidemiological factors contributing to cryptosporidiosis in underdeveloped countries – such as Cameroon – have insufficiently been studied. Currently available therapeutics show insufficient efficacies in the above mentioned risk groups. Cryptosporidium spp. are obligate intracellular protozoa which own minimal metabolic capacities. Consequently, to sustain their intracellular proliferation, these parasites have to modulate the host cellular metabolism. By characterizing metabolic signatures of C. parvum-infected host cells, we recently identified host cell metabolic reactions and pathways that are essential for parasite proliferation.

Cryptosporidium parvum- (yellow) infected host cells (nuclei: blue), tomographic microscopie © Juan Vélez

Inhibition of Cryptosporidium parvum via exemplary metabolic blockers (Vélez et al. 2021c)

Scientific goal:

This projects targets specific metabolic pathways of host cells (mainly glycolysis and glutaminolysis) by using new metabolic inhibitors or combinatory treatments. Moreover, a One Health study on several epidemiological factors of cryptosporidiosis in Cameroon is conducted.

DRUID Collaboration partners:

E4 Spengler lab

References D4: 1. *Vélez et al. (2021) Pathogens 11(1):49.  2.  * Vélez et al. (2021) Biology 10(10):963 3. ** Vélez et al. (2021) Biology 10(1):60