Biology subjects

Heussler, V. T.

Publications and source records attributed to Heussler, V. T..

3 recordsLinked to original sources

bioRxiv2026

Plasmodium berghei liver stages establish a damage-mimicking vacuole to hijack host ER membrane contact site machinery for lipid uptake

Plasmodium liver stage parasites undergo massive intracellular replication and therefore require extensive acquisition of host-derived lipids. How parasites coordinate lipid supply at the host-parasite interface, however, remains poorly understood. Here, we show that the Plasmodium berghei parasitophorous vacuole membrane (PVM) selectively mimics features of damaged endolysosomal membranes, including dynamic LC3-positive membrane tubules and PI4K2A-dependent PI(4)P accumulation, while lacking canonical damage markers including ESCRT components and galectins. This damage-mimicking membrane state drives OSBP recruitment and is associated with formation of VAPA/B-positive ER-PVM membrane contact sites. Disruption of VAPA/B or OSBP impaired PVM integrity and parasite survival, while OSBP depletion reduced cholesterol accumulation at the PVM. Together, our findings suggest that liver stage parasites exploit host lysosome repair-like pathways to redirect host lipids toward parasite growth and intracellular survival. These results redefine the PVM as an active metabolic interface that enables host lipid acquisition rather than merely serving as a protective barrier.

microbiology↗

bioRxiv2022

Small-molecule inhibitors targeting prokaryotic ClpQ protease in Plasmodium display anti-malarial efficacies against blood and liver stages

The ATP-dependent ClpQY system is a prokaryotic proteasome-like machinery in the mitochondrion of malaria parasite, Plasmodium. This protease system is identified as a validated target for malaria intervention. Here we have identified drug-like small chemical compounds, pyrimidotriazine derivatives, as specific inhibitors of P. falciparum ClpQ (PfClpQ) having effective parasiticidal efficacies on asexual and liver stages. Screening of the Malaria Box compound library, using a robust in vitro activity assay, identified a hit compound targeting the PfClpQ protease with IC50 at ~750nM. Further, Structure-Activity Relationship (SAR) analysis, using a small library of derivatives of the hit compound, identified three potential lead compounds, ICGEB-L1, ICGEB-L2 and ICGEB-L3, which inhibited enzyme activity with IC50 in 100-200nM ranges. The three lead compounds effectively inhibited in vitro asexual stage parasite growth in similar concentration ranges with ~100-fold selectivity over mammalian cell line; in addition, these compounds effectively inhibited in vitro growth and maturation of hepatocytic stage parasites with EC50 in low nano-molar ranges. These compounds were found to effectively block the development of trophozoite stages to schizont stage, concurrently arresting development and segregation of parasite mitochondria, in asexual as well as hepatocytic stages of the parasite. These morphological and developmental effects of the drugs on parasites mimic the data from genetic ablation of PfClpQ. Importantly, all three compounds showed significant in vivo anti-parasitic efficacies on blood stages of P. berghei mouse malaria model. Overall these results suggest that these PfClpQ targeting compounds are promising candidates to develop new anti-malarials.

microbiology↗

bioRxiv2020

Hijacking of the host cell Golgi by Plasmodium liver stage parasites

The intracellular lifestyle represents a challenge for the rapidly proliferating liver stage Plasmodium parasite. In order to scavenge host resources, Plasmodium has evolved the ability to target and manipulate host cell organelles. Using dynamic fluorescence-based imaging, we show a direct interplay between the pre-erythrocytic stages of Plasmodium berghei and the host cell Golgi during the entire liver stage development. Liver stage schizonts fragment the host cell Golgi into miniaturized stacks, which increases surface interactions with the parasites parasitophorous vacuole membrane. Interference with the host cell Golgi-linked vesicular machinery using specific dominant-negative Arf and Rab GTPases results in developmental arrest and diminished survival of liver stage parasites. Moreover, functional Rab11a is critical for the parasites ability to induce Golgi fragmentation. Altogether, we demonstrate that the structural and functional integrity of the host cell Golgi is necessary for optimal pre-erythrocytic development of P. berghei. The parasite hijacks the hepatocytes Golgi structure to optimize its own intracellular development.

cell biology↗