Biology subjects

Willems, C.

Publications and source records attributed to Willems, C..

4 recordsLinked to original sources

bioRxiv2026

A panel of biologically contained orthoebolaviruses for the screening of broad-spectrum antivirals

Filoviruses, particularly those of the Orthoebolavirus genus, pose ongoing public health threats due to their increasing frequency and geographic spread. However, research has been impeded by the biosafety level 4 classification of filoviruses. We previously reported the generation of biologically contained Ebola, Marburg and Sudan virus as lower biosafety level-compatible filovirus systems. In the present study, we expanded this repertoire to include biologically contained Tai Forest, Bundibugyo and Reston virus, thereby creating a near-complete toolkit for currently recognized human-relevant orthoebolaviruses. VP30-deficient viruses were generated with matching VP30 expressing cell lines. More specifically, we developed and optimized a dual-reporter system in VeroE6, Huh-7 and A549 cells, combining a virus-encoded enhanced green fluorescent protein reporter as readout for viral replication with a stably cellular-expressed nuclear mCherry marker for cytotoxicity assessment. Next, we screened two repurposing-oriented compound libraries comprising 640 small molecules against Tai Forest, Bundibugyo and Sudan virus, and subsequently cross-validated against Reston and Ebola virus. This approach identified multiple candidates with broad-spectrum activity across orthoebolaviruses, while also revealing virus-specific antivirals, with robust activity observed in both primate- and human-derived cell lines. Together, this work establishes a versatile and experimentally tractable lower biosafety level-compatible platform for the study of human-relevant orthoebolaviruses and the systematic discovery of broad-spectrum antiviral countermeasures against filoviruses.

microbiology↗

bioRxiv2024

A central role for CCR2 in monocyte recruitment and blood-brain barrier disruption during Usutu virus encephalitis

Usutu virus (USUV) is an emerging neurotropic flavivirus capable of causing encephalitis in humans. Here, our main goal was to characterize the innate immune response in the brain during USUV encephalitis and to identify strategies to control disease severity. Using an immunocompetent mouse model of USUV encephalitis, we showed that microglia activation, blood-brain barrier (BBB) disruption and inflammatory monocyte recruitment are hallmarks of disease 6 days post infection. Activated microglia were in close association to USUV-infected cells, concomitantly with elevated levels of IL-6, IFN-{gamma}, CCL2, CCL5, CXCL10 and CXCL1 in the brain. Monocyte recruitment was CCR2-dependent and driven by IFN-{gamma} and CCL2 production beneath the brain vasculature. Moreover, CCR2 deficiency inhibited microglia activation and BBB disruption, showing the central role of CCR2 in USUV encephalitis. Accordingly, treatment with dexamethasone prevented pro-inflammatory mediator production and reduced leukocyte recruitment significantly, restraining encephalitis severity. Concluding, USUV encephalitis is driven by CCR2-mediated monocyte recruitment and BBB disruption, and blocked therapeutically by glucocorticoids. SUMMARYThe neurotropic Usutu virus can cause encephalitis driven by CCR2-mediated monocyte recruitment, microglia activation and blood-brain barrier disruption, all of which are inhibited by glucocorticoid treatment.

immunology↗

bioRxiv2024

Three dimensionally printed microstructured alginate scaffolds for neural tissue engineering

The integration of scaffolds, signalling cues, and cellular components is essential in tissue engineering to create an in vivo equivalent environment that supports physiological function. Scaffolds provide mechanical reinforcement for cellular proliferation and differentiation while providing cues that instruct the development of cells during culture. Alginate (Alg) is a versatile biopolymer for scaffold engineering. However, due to a lack of intrinsic cell-binding sites, thus far, Alg must be functionalized for cellular adhesion. Here, we demonstrate proof-of-concept, bioactive additive-free, microstructured Alg (M-Alg) scaffolds for neuron culture. The M-Alg scaffold was formed by introducing tetrapod-shaped ZnO (t-ZnO) microparticles as structural templates in the Alg that were subsequently removed. These transparent, porous, additive-free Alg-based scaffolds with neuron affinity are promising for neuroregenerative and organoid- related research. HighlightsTetrapod-shaped ZnO (t-ZnO) microparticles are used as a template for the fabrication of open interconnected channels and textured surfaces in 3D printed microstructured alginate (M-Alg) scaffolds. Primary mouse cortical neurons seeded on the 3D printed M-Alg scaffolds show improved adhesion and maturation with extensive neural projections forming inside the scaffolds.

bioengineering↗

bioRxiv2022

3D Printed Neural Tissues with in situ Optical Dopamine Sensors

Engineered neural tissues serve as models for studying neurological conditions and drug screening. Besides observing the cellular physiological properties, in situ monitoring of neurochemical concentrations with cellular spatial resolution in such neural tissues can provide additional valuable insights in models of disease and drug efficacy. In this work, we demonstrate the first three-dimensional (3D) tissue cultures with embedded optical dopamine (DA) sensors. We developed an alginate/Pluronic F127 based bio-ink for human dopaminergic brain tissue printing with tetrapodal-shaped-ZnO microparticles (t-ZnO) additive as the DA sensor. DA quenches the autofluorescence of t-ZnO in physiological environments, and the reduction of the fluorescence intensity serves as an indicator of the DA concentration. The neurons that were 3D printed with the t-ZnO showed good viability, and extensive 3D neural networks were formed within one week after printing. The t-ZnO can sense DA in the 3D printed neural network with a detection limit of 0.137 M. The results are a first step toward integrating tissue engineering with intensiometric biosensing for advanced artificial tissue/organ monitoring.

bioengineering↗