Biology subjects

LeBeau, A. M.

Publications and source records attributed to LeBeau, A. M..

2 recordsLinked to original sources

bioRxiv2024

The structural basis for the selective antagonism of soluble TNF-alpha by shark variable new antigen receptors

The pro-inflammatory cytokine tumor necrosis factor-alpha (TNF)- is synthesized as transmembrane TNF- (tmTNF-) where proteolytic processing releases soluble TNF- (sTNF-). tmTNF- can act as either a ligand by activating TNF receptors, or a receptor that transmits outside-to-inside signals (reverse signalling) after binding to native receptors. All TNF- therapies bind tmTNF- and induce reverse signalling which can result in immunosuppression leading to infection. We present crystal structures of two anti-TNF- Variable New Antigen Receptors (VNAR) in complex with sTNF- via two distinct epitopes. The VNAR-D1 recognized an epitope that selectively engaged sTNF- while VNAR-C4 bound an epitope that overlapped with other biologic therapies. In activated CD4+ T cells, our VNARs did not bind tmTNF- in contrast to commercially available therapies that demonstrated induction of reverse signalling. Our findings suggest that neutralisation through a unique mechanism may lead to anti-TNF- agents with an improved safety profile that will benefit high-risk patients.

pharmacology and toxicology↗

bioRxiv2024

Unlocking Precision Gene Therapy: Harnessing AAV Tropism with Nanobody Swapping at Capsid Hotspots

Adeno-associated virus has been remarkably successful in the clinic, but its broad tropism is a practical limitation of precision gene therapy. A promising path to engineer AAV tropism is the addition of binding domains to the AAV capsid that recognize cell surface markers present on a targeted cell type. We have recently identified two previously unexplored capsid regions near the 2-fold valley and 5-fold pore of the AAV capsid that are amenable to insertion of larger protein domains including nanobodies. Here, we demonstrate that these hotspots facilitate AAV tropism switching through simple nanobody replacement without extensive optimization in both VP1 and VP2. We demonstrate highly specific targeting of human cancer cells expressing fibroblast activating protein (FAP). Our data suggest that engineering VP2 is the preferred path for maintaining both virus production yield and infectivity. Our study shows that nanobody swapping at multiple capsid location is a viable strategy for nanobody-directed cell-specific AAV targeting.

synthetic biology↗