Geukens, N. | Search bioRxiv

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↗

bioRxiv2021

Anti-SARS-CoV-2 human antibodies retaining neutralizing activity against SARS-CoV-2 B.1.1.529 (omicron)

SARS-CoV-2 B.1.1.529, designated omicron, was recently identified as a new variant of concern by WHO and is rapidly replacing SARS-CoV-2 delta as the most dominant variant in many countries. Unfortunately, because of the high number of mutations present in the spike of SARS-CoV-2 omicron, most monoclonal antibodies (mAbs) currently approved for treatment of COVID-19 lose their in vitro neutralizing activity against this variant. We recently described a panel of human anti-SARS-CoV-2 mAbs that potently neutralize SARS-CoV-2 Wuhan, D614G and variants alpha, beta, gamma and delta. In this work, we evaluated our mAb panel for potential in vitro activity against SARS-CoV-2 delta and omicron. Three mAbs from our panel retain neutralizing activity against both delta and omicron, with mAb 3B8 still resulting in complete neutralization at a concentration as low as 0.02 g/ml for both variants. Overall, our data indicate that mAb 3B8 may have the potential to become a game-changer in the fight against the continuously evolving SARS-CoV-2.

immunology↗

bioRxiv2021

Potent neutralizing anti-SARS-CoV-2 human antibodies cure infection with SARS-CoV-2 variants in hamster model

Treatment with neutralizing monoclonal antibodies (mAbs) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contributes to COVID-19 management. Unfortunately, SARS-CoV-2 variants can escape several of these recently approved mAbs, highlighting the need for additional discovery and development. In a convalescent COVID-19 patient, we identified six mAbs, classified in four epitope groups, that potently neutralized SARS-CoV-2 Wuhan, alpha, beta, gamma and delta infection in vitro. In hamsters, mAbs 3E6 and 3B8 potently cured infection with SARS-CoV-2 Wuhan, beta and delta when administered post-viral infection at 5 mg/kg. Even at 0.2 mg/kg, 3B8 still reduced viral titers. Intramuscular delivery of DNA-encoded 3B8 resulted in in vivo mAb production of median serum levels up to 90 g/ml, and protected hamsters against delta infection. Overall, our data mark 3B8 as a promising candidate against COVID-19, and highlight advances in both the identification and gene-based delivery of potent human mAbs.

immunology↗