Subcellular trafficking and transcytosis efficacy of different receptor types for therapeutic antibody delivery at the blood‒brain barrier

Abstract

Here, we report an experimental setup to benchmark different receptors for targeted therapeutic antibody delivery at the blood–brain barrier. We used brain capillary endothelial-like cells derived from induced pluripotent stem cells (hiPSC-BECs) as a model system and compared them to colon epithelial Caco-2 cells. This approach helped to identify favourable receptors for transport into the cell layer itself or for directing transport for transcytosis across the cell layer. The sorting receptors transferrin receptor and sortilin were shown to be efficient as antibody cargo receptors for intracellular delivery to the cell layer. In contrast, the cell surface receptors CD133 and podocalyxin were identified as static and inefficient receptors for delivering cargo antibodies. Similar to in vivo studies, the hiPSC-BECs maintained detectable transcytotic transport via transferrin receptor, while transcytosis was restricted using sortilin as a cargo receptor. Based on these findings, we propose the application of sortilin as a cargo receptor for delivering therapeutic antibodies into the brain microvascular endothelium. Graphical Abstract

Characterization of an iPSC-based barrier model for blood-brain barrier investigations using the SBAD0201 stem cell line

“…The in vitro BBB models include the use of human induced pluripotent stem cells (hiPSCs), umbilical cord blood-derived hematopoietic stem cells, and amniotic fluid-derived stem cells [ 16 – 22 ]. The stem cells are cultured in complex media to differentiate them into brain capillary endothelial-like cells, which are subsequently cultured on permeable supports to form cell monolayers [ 16 , 17 , 19 , 21 , 23 ]. The resulting cell monolayers exhibit restrictive barrier properties and expression of essential proteins, such as tight junctions, solute carriers, receptors, and efflux transporters [ 24 ].…”