Biology subjects

Pascal, C.

Publications and source records attributed to Pascal, C..

4 recordsLinked to original sources

bioRxiv2026

Next Generation TB Drug Combinations from the Pan-TB Consortium: Combination Efficacy and Contributions of Individual Agents, Evaluated in a BALB/c Mouse TB Model

The Project to Accelerate New Treatments for Tuberculosis (PAN-TB) aims to accelerate development of shorter, simpler and safer pan-TB combinations. We previously identified 3 out of 25 first-generation novel PAN-TB 4-drug combinations, that cured 90% of mice in less than 3 months, at clinically relevant doses in the relapsing mouse model of TB. These regimens include BPa830Sut, BPa286Sut and BQSut286 (B: bedaquiline; Pa: pretomanid; 830: GSK3211830; 286: GSK2556286; Sut: sutezolid; Q: quabodepistat). Here, we assess the efficacy of these combinations where the original candidates are substituted next-generation or more advanced compounds (ganfeborole (656) for 830, sorfequiline, S for B, TBD09 for Sut and TBD11 for 286) and the individual contributions of specific agents. Six novel regimens demonstrated bactericidal activity more rapid than comparators PHMZ (Rifapentine P, Isoniazid H, Moxifloxacin M, Pyrazinamide Z) and BPaMZ. Modelled cure/relapse data showed that SPa286Sut, SPaSut and SPa656Sut cured 90% of mice in about 1 month, while SPa286, SPaQTBD11 and SPaTBD09 in less than 2 months, faster than PHMZ. Consistent with our previous findings, the fastest-curing regimens centered on a diarylquinoline (S), a nitroimidazole (Pa) and an oxazolidinone (TBD09 or Sut) together with an Rv1625c agonist (TBD11 or 286), DprE1 inhibitor (Q) or a LeuRS inhibitor (656). Notably, significant contributions to sterilizing efficacy were demonstrated for S in all combinations and for Pa, Sut, TBD09, Q and TBD11 or 286 in specific S-containing combinations. These findings suggest potential for these novel agents and combinations to improve treatment of both DS-and DR-TB.

pharmacology and toxicology↗

bioRxiv2026

Nonclinical pharmacokinetics and relative efficacy of the first 25 novel tuberculosis drug combinations from the PAN-TB consortium: Use of the BALB/c relapsing mouse model and combination pharmacokinetics within a modeling-based framework

The Project to Accelerate New Treatments for Tuberculosis (PAN-TB) aims to accelerate development of shorter, simpler and safer pan-TB combinations, effective for use in both Drug Susceptible (DS)- and Drug Resistant (DR)- TB patients. Towards this aim, bactericidal and sterilizing activity of 25 priority 4-drug combinations was evaluated at doses targeting clinically relevant exposures, in the BALB/c relapsing mouse model of TB. The combinations comprised 8 PAN-TB drugs and candidates: bedaquiline (B), pretomanid (Pa), delamanid (Del), quabodepistat (Q), sutezolid (Sut), GSK2556286 (286), GSK3211830 (830) and ganfeborole (GSK3036656, (656)). Combination PK studies in infected mice enabled dose selection and a population-PK approach guided dosing so that compounds should achieve mean AUC0-24 within 2-fold of their clinical target exposures during the efficacy studies. All test combinations showed time-dependent bactericidal activity, with six regimens reducing lung bacterial burdens below the limit of detection with 8 weeks treatment, similar to the comparator BPaMZ (M is moxifloxacin and Z as pyrazinamide). Cure/Relapse data were modelled to derive population time to cure 90% mice (T90) values. Fifteen PAN-TB combinations had T90s of less than 5 months, sterilizing mice faster than the standard of care for drug susceptible TB, RHZE/RH. The best-performing PAN-TB combinations, BPa830Sut, BPa286Sut and BQSut286, cured 90% of mice in less than 3 months. These 3 top-ranked 4-drug combinations are all centered on a diarylquinoline (B)/oxazolidinone (Sut) core, together with the nitroimidazole (Pa) or a DprE1 inhibitor (Q) plus a novel agent such as the LeuRS inhibitor (830) or the Rv1625c agonist (286).

microbiology↗

bioRxiv2025

Dynamics and interplay of gene expression and chromosome organization across a predatory lifecycle

The obligate predatory bacterium Bdellovibrio bacteriovorus alternates between a motile attack phase and a growth phase inside another bacterium, during which it undergoes multiple rounds of DNA replication followed by non-binary division and progeny release. How its chromosome is dynamically reorganized across these contrasting states remains unclear. Here, we used synchronized predatory infections combined with time-resolved RNA-seq, Hi-C, ChIP-seq, and quantitative microscopy to map transcriptional activity and chromosome architecture across seven key stages of the predatory lifecycle. We uncover a dramatic shift in nucleoid organization - from an ultra-compact, transcriptionally restricted state in attack-phase cells to a progressively decompacted, ori-centered conformation during intracellular replication. Notably, distinct transcriptional and chromosome folding states not only mark the canonical attack and growth phases, but also critical transitions such as prey invasion, replication onset, and predator division. Temporal gene expression profiles reflect the coordinated regulation of core cellular functions across the predatory cycle. Furthermore, spatial localization of RNA polymerase, ribosomes, DNA-binding proteins, and freely diffusing proteins highlight the tight, cell cycle-dependent coupling between nucleoid compaction, chromosome accessibility, and transcriptional activity. Altogether, our findings reveal the intricate dynamics and coordination of genome folding and gene expression in a complex bacterial cell cycle driven by prey-predator interactions.

microbiology↗

bioRxiv2019

Patterns of linkage disequilibrium reveal genome architecture in chum salmon

Many studies exclude loci exhibiting linkage disequilibrium (LD); however, high LD can signal reduced recombination around genomic features such as chromosome inversions or sex-determining regions. Chromosome inversions and sex-determining regions are often involved in adaptation, allowing for the inheritance of co-adapted gene complexes and for the resolution of sexually antagonistic selection through sex-specific partitioning of genetic variants. Genomic features such as these can escape detection when loci with LD are removed; in addition, failing to account for these features can introduce bias to analyses. We examined patterns of LD using network analysis to identify an overlapping chromosome inversion and sex-determining region in chum salmon. The signal of the inversion was strong enough to show up as false population substructure when the entire dataset was analyzed, while the signal of the sex-determining region was only obvious after restricting genetic analysis to the sex chromosome. Understanding the extent and geographic distribution of inversions is now a critically important part of genetic analyses of natural populations. The results of this study highlight the importance of analyzing and understanding patterns of LD in genomic dataset and the perils of ignoring or excluding loci exhibiting LD.

genomics↗