Biology subjects

Dewilde, M.

Publications and source records attributed to Dewilde, M..

6 recordsLinked to original sources

bioRxiv2025

The Alzheimer's therapeutic Lecanemab induces an amyloid-clearing program in microglia

Controversies over anti-amyloid immunotherapies underscore the need to elucidate their mechanisms of action. Here we demonstrate that Lecanemab, a leading anti-A{beta} antibody, mediates amyloid clearance by triggering effector functions in the microglia. Using a human microglia xenograft model, we show that Lecanemab significantly reduces A{beta} pathology and associated neuritic damage, while neither Fc-inactivated Lecanemab nor microglia deficiency elicit this effect despite intact plaque binding. Single-cell RNA sequencing and spatial transcriptomic analyses reveal that Lecanemab induces a focused transcriptional program that enhances phagocytosis, lysosomal degradation, metabolic reprogramming, interferon gamma genes, and antigen presentation. Finally, we identify SPP1/osteopontin as a major factor induced by Lecanemab treatment and demonstrate its role in promoting A{beta} clearance. These findings highlight that effective amyloid removal depends on the engagement of microglia through Fc fragment, providing critical insights for optimizing anti-amyloid therapies in AD.

neuroscience↗

bioRxiv2024

A pair of congenic mice for imaging of transplants by positron emission tomography using anti-transferrin receptor nanobodies

Two anti-transferrin receptor (TfR) nanobodies, VHH123 specific for mouse TfR and VHH188 specific for human TfR (huTfR) were used to track transplants non-invasively by PET/CT in mouse models, without the need for genetic modification of the transferred cells. We provide a comparison of the specificity and kinetics of the PET signals acquired when using nanobodies radiolabeled with 89Zr, 64Cu and 18F, and find that the chelation of the 89Zr and 64Cu radioisotopes to anti-TfR nanobodies results in radioisotope release upon endocytosis of the radiolabeled nanobodies. We used a knock-in mouse that expresses a TfR with a human ectodomain (huTfR +/+) as a source of bone marrow for transplants into C57BL/6 recipients and show that VHH188 detects such transplants by PET/CT. Conversely, C57BL/6 bone marrow and B16.F10 melanoma cell-line transplanted into huTfR +/+ recipients can be imaged with VHH123. In C57BL/6 mice impregnated by huTfR+/+ males we saw an intense VHH188 signal in the placenta, showing that TfR-specific VHHs accumulate at the placental barrier but do not enter the fetal tissue. We were unable to observe accumulation of the anti-TfR radiotracers in the central nervous system (CNS) by PET/CT but show evidence of CNS accumulation by radiospectrometry. The model presented here can be used to track many transplanted cell types by PET/CT, provided cells express TfR, as is typically the case for proliferating cells such as tumor lines.

immunology↗

bioRxiv2024

Increasing brain half-life of antibodies by additional binding to myelin oligodendrocyte glycoprotein, a CNS specific protein

BackgroundTherapeutic antibodies for the treatment of neurological disease show great potential, but their applications are rather limited due to limited brain exposure. The most well-studied approach to enhance brain influx of protein therapeutics, is receptor-mediated transcytosis (RMT) by targeting nutrient receptors to shuttle protein therapeutics over the blood-brain barrier (BBB) along with their endogenous cargos. While higher brain exposure is achieved with RMT, the timeframe is short due to rather fast brain clearance. Therefore, we aim to increase the brain half-life of antibodies by binding to myelin oligodendrocyte glycoprotein (MOG), a CNS specific protein. MethodsAlpaca immunization with mouse/human MOG, and subsequent phage selections and screenings for MOG binding VHHs were performed to find mouse/human cross-reactive VHHs. Their ability to increase the brain half-life of antibodies was evaluated by coupling two different MOG VHHs (low/high affinity) in a mono- and bivalent format to an anti-{beta}-secretase 1 or anti-SarsCov2 antibody fused to an anti-transferrin receptor (TfR) VHH for active transport over the BBB. Brain pharmacokinetics and pharmacodynamics, CNS and peripheral biodistribution, and brain toxicity were evaluated after intravenous administration to balb/c mice. ResultsAdditional binding to MOG increases the Cmax and brain half-life of antibodies that are actively shuttled over the BBB. biMOGLow:monoTfR:SarsCov antibodies could be detected in brain 49 days after a single intravenous injection, which is a major improvement compared to monoTfR:SarsCov antibodies which cannot be detected in brain anymore one week post treatment. Additional MOG binding of antibodies does not affect peripheral biodistribution but alters brain distribution to white matter localization and less neuronal internalization. ConclusionsWe have discovered mouse/human/cyno cross-reactive anti-MOG VHHs which have the ability to drastically increase brain exposure of antibodies. Combining MOG and TfR binding leads to distinct PK, biodistribution, and brain exposure, differentiating it from the highly investigated TfR- shuttling. It is the first time such long brain antibody exposure is demonstrated after one single dose. This new approach of adding a binding moiety for brain specific targets to RMT shuttling antibodies is a huge advancement for the field and paves the way for further research into brain half-life extension.

pharmacology and toxicology↗

bioRxiv2024

Single-molecule characterisation of soluble beta-amyloid aggregate binding by Aducanumab, Lecanemab, Gantenerumab, and Donanemab

Monoclonal antibodies Aducanumab, Lecanemab, Gantenerumab, and Donanemab have been developed for treatment of Alzheimers disease. Here, we have used single-molecule detection techniques and super-resolution imaging to characterise the binding of these antibodies to beta-amyloid aggregates including human post-mortem brain samples. Lecanemab is the best antibody in terms of binding to the small-soluble beta-amyloid aggregates, affinity, aggregate coating, and the ability to bind to post-translationally modified species, explaining its therapeutic success.

neuroscience↗

bioRxiv2023

Microfluidic interfaces for chronic bidirectional access to the brain.

AO_SCPLOWBSTRACTC_SCPLOWHere, we used micron-scale 3D printing to develop microfluidic interfaces which provide chronic fluidic access to the brain of preclinical research models. In mice, we show the delivery interface enables faster, more precise and physiologically less disruptive fluid injection. Moreover, we demonstrate the blood brain barrier (BBB) is intact after chronic implantation of the sampling interface and establish frequent, longitudinal sampling of CSF and biomarkers from the ventricle over long time periods of up to 200 days.

neuroscience↗

bioRxiv2019

AAV mediated delivery of a novel anti-BACE1 VHH reduces Abeta in an Alzheimer’s disease mouse model

Single domain antibodies (VHH) are potentially disruptive therapeutics, with important biological value for treatment of several diseases, including neurological disorders. However, VHH have not been widely used in the central nervous system (CNS), as it is hard to reach therapeutic levels, both because of their restricted blood-brain-barrier penetration and their apparent rapid clearance from the parenchyma. Here, we propose a gene transfer strategy based on adeno-associated virus (AAV)-based vectors to deliver VHH directly into the CNS, ensuring continuous production at therapeutic levels. As a proof-of-concept, we explored the potential of AAV-delivered VHH to inhibit BACE1, a well-characterized target in Alzheimers disease. First, we generated a panel of VHHs targeting BACE1. One of them, VHH-B9, showed high selectivity for BACE1 and efficacy in lowering BACE1 activity in vitro. We then went on to demonstrate significant reductions in amyloid beta (A{beta}) levels after AAV-based delivery of VHH-B9 into the CNS of a mouse model of cerebral amyloidosis. These results constitute a novel therapeutic approach for neurodegenerative diseases, which is applicable to a range of CNS disease targets.

neuroscience↗