| Download | - View accepted manuscript: Intracellular sorting and transcytosis of the rat transferrin receptor antibody OX26 across the blood-brain barrier in vitro is dependent on its binding affinity (PDF, 1.5 MiB)
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| DOI | Resolve DOI: https://doi.org/10.1111/jnc.14482 |
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| Author | Search for: Haqqani, Arsalan S.1; Search for: Thom, George; Search for: Burrell, Matthew; Search for: Delaney, Christie E.1; Search for: Brunette, Eric1; Search for: Baumann, Ewa1; Search for: Sodja, Caroline1; Search for: Jezierski, Anna1; Search for: Webster, Carl; Search for: Stanimirovic, Danica B.1 |
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| Affiliation | - National Research Council of Canada. Human Health Therapeutics
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| Format | Text, Article |
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| Subject | blood-brain barrier; transferrin receptor antibody; intracellular trafficking; quantitative targeted proteomics; affinity optimization; analgesic peptides |
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| Abstract | The blood‐brain barrier (BBB) is a formidable obstacle to the delivery of therapeutics to the brain. Antibodies that bind transferrin receptor, which is enriched in brain endothelial cells, have been shown to cross the BBB and are being developed as fusion proteins to deliver therapeutic cargos to brain targets. Various antibodies have been developed for this purpose and their in vivo evaluation demonstrated that either low affinity or mono‐valent receptor binding re‐directs their transcellular trafficking away from lysosomal degradation and towards improved exocytosis on the abluminal side of the BBB. However, these studies have been performed with antibodies that recognize different TfR epitopes and have different binding characteristics, preventing inter‐study comparisons. In this study, the efficiency of transcytosis in vitro and intracellular trafficking in endosomal compartments were evaluated in an in vitro BBB model for affinity variants (Kd from 5 nM ‐174 nM) of the rat TfR‐binding antibody, OX26. Distribution in subcellular fractions of the rat brain endothelial cells was determined using both targeted quantitative proteomics (SRM) and fluorescent imaging with markers of early‐ and late endosomes. The OX26 variants with affinities of 76 nM and 108 nM showed improved trancytosis (Papp values) across the in vitro BBB model compared to a 5 nM OX26. Whereas ~40% of the 5 nM OX26 and ~35% of TfR co‐localized with late‐endosome/lysosome compartment, 76 nM and 108 nM affinity variants showed lower amounts in lysosomes and a predominant co‐localization with early endosome markers. The study links bi‐valent TfR antibody affinity to mechanisms of sorting and trafficking away from late endosomes and lysosomes, resulting in improvement in their transcytosis efficiency. |
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| Publication date | 2018-06-07 |
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| Publisher | Wiley |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| NPARC number | 23003373 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | 22649941-2953-4e7d-a3da-3077e161e127 |
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| Record created | 2018-06-12 |
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| Record modified | 2020-06-03 |
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