Bedi, R. | bioRxiv Science

bioRxiv2022

Venom protection by antibody from a snakebite hyperimmune subject

Snake envenomation is a neglected tropical disease, causing >100,000 deaths and 300,000 permanent disabilities in humans annually. Could monoclonal antibody technology provide a solution? Here, we recover Centi-3FTX-D09, a potent broadly neutralizing antivenom antibody from the B-cell memory of a human subject with snake venom exposure. Centi-3FTX-D09 recognized a conserved neutralizing epitope on long 3-finger toxins (3FTXs), a dominant snake neurotoxin. Crystal structures of Centi-3FTX-D09 in complex with 3FTXs from mamba, taipan, krait, and cobra revealed epitope mimicry of the interface between these neurotoxins and their host target, the nicotinic acetylcholine receptor. Centi-3FTX-D09 provided in-vivo protection against diverse recombinant long 3FTXs, in-vivo rescue from whole venom challenge from cobras, black mamba, and king cobra, and, when combined with the phospholipase inhibitor varespladib, in-vivo protection extending to a majority of tested elapid venoms. Thus, a single antibody can broadly neutralize long neurotoxins and contribute to broad protection from envenomation.

immunology↗

bioRxiv2020

Optimization and scaling of patient-derived brain organoids uncovers deep phenotypes of disease

Cerebral organoids provide unparalleled access to human brain development in vitro. However, variability induced by current culture methodologies precludes using organoids as robust disease models. To address this, we developed an automated Organoid Culture and Assay (ORCA) system to support longitudinal unbiased phenotyping of organoids at scale across multiple patient lines. We then characterized organoid variability using novel machine learning methods and found that the contribution of donor, clone, and batch is significant and remarkably consistent over gene expression, morphology, and cell-type composition. Next, we performed multi-factorial protocol optimization, producing a directed forebrain protocol compatible with 96-well culture that exhibits low variability while preserving tissue complexity. Finally, we used ORCA to study tuberous sclerosis, a disease with known genetics but poorly representative animal models. For the first time, we report highly reproducible early morphological and molecular signatures of disease in heterozygous TSC+/- forebrain organoids, demonstrating the benefit of a scaled organoid system for phenotype discovery in human disease models.

neuroscience↗