Henrico Langeveld

@henricol28.bsky.social

Postdoctoral fellow. Doing some research on the Malaria Parasites 🧫🔬🥼U-ExM 🔬is the coolest… change my mind 😉 | 📍Birkholtz Lab, South Africa 🇿🇦| https://b-lab.health/#cbe0f978-dd6d-4cfd-9b6e-5ed959b07142

Single-cell analysis of Plasmodium falciparum transcripts after drug perturbation identifies feedback regulation as well as increased transmission potential bioRxivpreprint

Single-cell analysis of Plasmodium falciparum transcripts after drug perturbation identifies feedback regulation as well as increased transmission potential

Gene expression analysis in malaria parasites has been used to define transcriptional regulatory networks but has been used less frequently to characterize parasite response to drug treatment or to show how parasites may evade killing. Here, we applied single-cell RNA sequencing (scRNA-seq) to hundreds of thousands of individually infected asynchronous red blood cells to evaluate the parasite's response to treatment with three chemotypes that can be used for treatment (artemisinin) or prophylaxis and treatment (atovaquone, ganaplacide). We found that each treatment gave rise to different cell populations with different transcriptional profiles. Comparing single cell transcription patterns in compound-treated cells, to transcript patterns observed previously with synchronized cells showed an enrichment of cells expressing gametocyte-associated genes after artemisinin treatment but fewer lifecycle perturbations after treatment with the two other compounds. In contrast, bulk analysis showed an enrichment of pyrimidine biosynthesis transcripts for atovaquone treatment. Our results show that scRNA-seq may be used to profile diverse drug responses across many lifecycle stages and to potentially classify drug classes.

dlvr.it

Potent reaction hijacking inhibitors of Plasmodium falciparum asparagine tRNA synthetase bioRxivpreprint

Potent reaction hijacking inhibitors of Plasmodium falciparum asparagine tRNA synthetase

Malaria remains one of the major threats to human health. Breakthrough drugs with high potency and low resistance risk are needed to combat the ever-increasing resistance to currently deployed antimalarials. Here, we explore a series of 4-amino-quinazoline-based sulfonamides, with drug-like physicochemical parameters and a synthetically accessible scaffold. Exemplars exhibit nanomolar potency against blood stage Plasmodium cultures, with up to 300-fold selectivity compared with a mammalian cell line. The compounds are also active against transmissible stages of P. falciparum and are refractory to resistance development. Targeted mass spectrometry reveals that the compounds act as reaction hijacking inhibitors targeting P. falciparum aminoacyl tRNA synthetases (aaRSs). Subtle changes to the chemical structure switch the main target from cytoplasmic tRNA threonine synthetase (PfThrRS) to cytoplasmic asparagine synthetase (PfAsnRS), a change that is associated with increased potency and selectivity. The target preference was confirmed by selective knock-down of different P. falciparum aaRSs and by tolerance selection in a mutator line. Consistent with aaRS targets, exemplar compounds activate the amino acid starvation response. Recombinant enzyme inhibition and thermal stabilisation assays confirm the susceptibility of PfAsnRS to reaction hijacking and show that human AsnRS is less susceptible. A molecular model of Asn-tRNA-bound PfAsnRS reveals that a potent hijacker adopts a pose similar to adenosine 5-monophosphate (AMP). An AlphaFold model of the native PfAsnRS dimer helps explain the tolerance-conferring effect of a mutation at the dimer interface.

dlvr.it

What a surreal feeling seeing my first preprint manuscript 🤩🥳 Please go have a look at our “hot off the press” preprint from the Birkholtz Lab where we validate a PfArk1 tool compound and use it to investigate the biological function of PfArk1 during multiple parasite stages

Bloodsucking Parasites@bloodsparasites.bsky.social · last yr.

Targeting Aurora kinases as essential cell cycle regulators to deliver multi-stage antimalarials against Plasmodium falciparum bioRxivpreprint

Just returned from an incredible week at BioMalPar 🧬🥼🧫🧪 in Germany — a truly memorable experience both scientifically and personally. Grateful for the opportunity to engage with leading minds in malaria research, forge new connections, and experience the beauty and culture of Germany🇩🇪

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Shared some really exciting science from the Birkholtz Lab on antimalarial drug discovery and P. falciparum biology—spotlight on Aurora kinases. Thank you @H3D for this opportunity PS: Yes, that’s me at the back, while being a bit star struck🤩

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Would have loved to be able to be there in person, but excited and proud to see a great colleague and a great friend in James Blauwkamp deliver a fantastic PhD Defence! Been a wonderful experience to see you grow as a scientist over the years and excited to see what's next 🎉 @sabsalon.bsky.social

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