The central aim of this axis is the development of new potent analgesics, building on the detailed elucidation of the AT2R-Traak model. To reach this aim the project involving 6 teams in France (Marsollier, Lebon, Sandoz, Boustié, Yeramian and Brodin) deploys a full-spectrum approach, from detailed molecular and cellular characterizations, to extensive exploratory screenings of natural compounds and in vivo pain assessments. The project is characterized by several promising strengths, as well as notable safeguards relative to the risks inherent to such approaches:
1) The effect of mycolactone appears to be very long lasting, thus comparing very favourably to compounds such as morphine, with the short duration of action being recognized as a severe shortcoming.
2) The system under study appears to be significantly more complex than other bioinspirational models for analgesia (for example scorpion toxins acting directly on ion channels), making the study more difficult, but offering from the applications perspective many different handles to interfere with the system.
3) The scientific approach adopted provides a sound safeguard relative to the medical objectives of the project, as the expected informations concerning the poorly characterized AT2R GPCR receptor and the Traak ionic channel will be valuable for their own sakes, notably in view of the increasing appreciation of the physiological importance of these components.
ANR Grant AT2R Traak Bionanalgesics coordinated by Priscille BRODIN (PI) (2018-2021)
Mtb /macrophages/control of acidification / Tirap-CISH-vATPase
Stemming from our work , we will further characterize the complex formed by CISH and H+ V-ATPase at the vacuole through a higher spatial and temporal image-based approach. For the identification of other potential partners in the complex, we will perform a high throughput proteomic approach directly on Mtb containing phagosomes isolated from macrophages by immune-affinity separation. We will further
characterize the role of ubiquitination on the H+ V-ATPase. A more global approach aiming at deciphering the dual role of the host ubiquitinome at the Mtb containing vacuole will also be undertaken. Recently, we could also show that the TLR adaptor Tirap (also called MAL) is required for STAT5 phosphorylation and CISH expression, which suggests that Tirap is critical for CISH-mediated bacterial control. Strikingly, the inhibition of bacterial replication is strikingly more pronounced in Tirap-/- compared to Cish-/- macrophages and mice suggesting a unique role of Tirap, which will be further elucidated.
I-SITE UNLE ERC-Generator Grant (2019)
Small-molecules, antimicrobial peptides and combination of against intracellular Mtb
The drug discovery efforts and focus on chemical biology in Lille includes medical chemistry, high content screening capacity, target identification, nanoparticles drug delivery systems and in vivo validation should definitely continue to position us as key player in the field of therapeutics against TB. We will focus on drug candidates (either alone or in combination) having efficacy against Mtb replication within macrophages (also called antivirulence compounds or host-directed therapy). Our approaches will rely on i) the repurposing of commercially available drugs; and ii) the development of proprietary antimicrobial peptides (AMP) brought by Aurélie TASIEMSKI and François MASSOL joining the team in 2020. They identified a new antibiotic peptide, alvinellacin, from Alvinella pompejana, the emblematic worm that inhabits the hottest part of deep sea hydrothermal chimneys of the East Pacific Rise.This patented peptide (Aurélie Tasiemski et a lPatent number: 8652514 / Univ Lille) is the first active molecule against Mtb isolated from an extremophile animal and shows no homology to other molecules already described from terrestrial or marine organisms. The peptide folds into a double-stranded antiparallel β- sheet (β-hairpin motif) stabilized by two cysteine-bonds, which is unique to worms so far. Together with other molecules belonging to the same gene family and all issued from extremophile animals, their development against TB will be pursued using our efficient hit-to-lead optimisation pipeline. A. Tasiemski is invited to several oceanographic cruises giving access to extremophile organisms.
SATT Nord coordinated by Aurélie TASIEMSKI
Risk of resistance development of novel TB drug candidates
Theoretical models of biological evolution will be developed to predict the conditions of emergence of Mtb resistance against the proposed treatments, using the modelling frameworks of quantitative genetics and adaptive dynamics (32, 33). The prediction model will be confronted to the results of selection of resistant strains during long-term exposure to sub-lethal doses of drugs on the Mtb infected macrophages. Different models will be designed to account for possible genetic correlations between tolerance and resistance and will incorporate different ingredients which can potentially enhance the acquisition of resistance in bacteria such as i) the capacity for tolerance against antibiotics (i.e. survival through a decrease in intracellular bacterial growth), ii) the type of interaction linking the immune system to pathogens with respect to host resources, iii) source-sink dynamics between reservoirs of pathogen resistance acquisition and immunitydeprived patients.