A human blood-brain barrier transcytosis assay reveals antibody transcytosis influenced by pH-dependent receptor binding.
We have adapted an in vitro model of the human blood-brain barrier, the immortalized human cerebral microvascular endothelial cells (hCMEC/D3), to quantitatively measure protein transcytosis. After validating the receptor-mediated transport using transferrin, the system was used to measure transcytosis rates of antibodies directed against potential brain shuttle receptors. While an antibody to the insulin-like growth factor 1 receptor (IGF1R) was exclusively recycled to the apical compartment, the fate of antibodies to the transferrin receptor (TfR) was determined by their relative affinities at extracellular and endosomal pH. An antibody with reduced affinity at pH5.5 showed significant transcytosis, while pH-independent antibodies of comparable affinities at pH 7.4 remained associated with intracellular vesicular compartments and were finally targeted for degradation.
Large Molecule Research, Pharma Research and Early Development (pRED), Roche, Penzberg, Germany.
Hadassah
H
Sade
Large Molecule Research, Pharma Research and Early Development (pRED), Roche, Penzberg, Germany.
Claudia
C
Baumgartner
Large Molecule Research, Pharma Research and Early Development (pRED), Roche, Schlieren, Switzerland.
Adrian
A
Hugenmatter
Large Molecule Research, Pharma Research and Early Development (pRED), Roche, Schlieren, Switzerland.
Ekkehard
E
Moessner
Neuroscience Discovery and Translation Area, Pharma Research and Early Development (pRED), F. Hoffmann-La Roche, Basel, Switzerland.
Per-Ola
PO
Freskgård
Large Molecule Research, Pharma Research and Early Development (pRED), Roche, Penzberg, Germany.
Jens
J
Niewoehner
D000906:Antibodies / Q000276:immunology / Q000378:metabolism*; D015703:Antigens, CD / Q000276:immunology; D001812:Blood-Brain Barrier / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017526:Receptor, IGF Type 1 / Q000276:immunology; D011990:Receptors, Transferrin / Q000276:immunology; D057900:Transcytosis
D000906:Antibodies; D015703:Antigens, CD; C068126:CD71 antigen; D011990:Receptors, Transferrin; D017526:Receptor, IGF Type 1