Current Approaches and Future Perspectives for Nanobodies in Stroke Diagnostic and Therapy

Abstract

Antibody-based biologics are the corner stone of modern immunomodulatory therapy. Though highly effective in dampening systemic inflammatory processes, their large size and Fc-fragment mediated effects hamper crossing of the blood brain barrier (BBB). Nanobodies (Nbs) are single domain antibodies derived from llama or shark heavy-chain antibodies and represent a new generation of biologics. Due to their small size, they display excellent tissue penetration capacities and can be easily modified to adjust their vivo half-life for short-term diagnostic or long-term therapeutic purposes or to facilitate crossing of the BBB. Furthermore, owing to their characteristic binding mode, they are capable of antagonizing receptors involved in immune signaling and of neutralizing proinflammatory mediators, such as cytokines. These qualities combined make Nbs well-suited for down-modulating neuroinflammatory processes that occur in the context of brain ischemia. In this review, we summarize recent findings on Nbs in preclinical stroke models and how they can be used as diagnostic and therapeutic reagents. We further provide a perspective on the design of innovative Nb-based treatment protocols to complement and improve stroke therapy.

FluoSTEPs: Fluorescent biosensors for monitoring compartmentalized signaling within endogenous microdomains

“…Strategies have been developed to address the overexpression concerns such as using nanobodies for highlighting endogenous, active receptors and using intrabodies to recruit biosensors to endogenous compartments ( 9 , 10 ). However, perturbations in trafficking and signaling due to nanobody binding, as well as issues of compartment specificity, are still ever-present ( 9 , 11 , 12 ). Ideally, an approach that combined the strength of quantitative biosensing, specificity of genetic fusions, and minimal perturbation of endogenous POIs would be valuable for dissecting compartmentalized signaling within living cells.…”

Camelid VHHs Fused to Human Fc Fragments Provide Long Term Protection Against Botulinum Neurotoxin A in Mice

“…However, the advantages of VHHs may also become their impediments. Their small size enables good penetration into tissue and rapid distribution, but their short half-life in the blood circulation limits the time for interaction with hard-to-reach epitopes and for crossing endothelial barriers in sufficient amounts [27,29,30]. Nevertheless, due to their relatively simple structure, VHHs can be optimized by genetic engineering to obtain desired properties, including extended half-lives [29].…”

Driving CARs with alternative navigation tools – the potential of engineered binding scaffolds

“…Separate expression of these V HH domains yields single‐domain antibody fragments (~15 kDa) that are commonly referred to as nanobodies (Fig. 4A) [55]. Because the light chain is missing in nanobodies, they do not require additional folding steps as is required for scFvs, where the V H and V L need to assemble.…”