Immunohistochemical localization of the murine transferrin receptor (TfR) on blood-tissue barriers using a novel anti-TfR monoclonal antibody

Abstract

A novel monoclonal antibody (mAb), 8D3 (IgG2a), that specifically recognizes the murine transferrin receptor (TfR) was produced by immunizing a Lewis rat with a polyoma middle T oncogene-transformed endothelioma cell line. The 8D3 mAb was obtained by immunohistochemical screening for exclusive staining of vessels forming a blood-brain barrier (BBB), but not of other vessels. The anti-TfR mAb 8D3 recognizes the TfR also in FACS analysis and in western blots and should prove to be useful for affinity purification of the TfR. Whereas 8D3 brightly stains BBB-forming vessels in the central nervous system of mice, it does not stain the fenestrated capillaries within the choroid plexus and the circumventricular organs. In testis, where the blood-tissue barrier is located at the level of the Sertoli cells, the 8D3 mAb specifically stains Sertoli cells but not endothelial cells. Finally, in vitro, 8D3 does not interfere with iron uptake of lymphocytes as it does not influence their proliferation. Taken together, 8D3 represents a versatile new tool to study the tissue distribution of the murine TfR and TfR-mediated transcytosis across tissue barriers in the mouse.

Developing Therapeutic Antibodies for Neurodegenerative Disease

“…Conjugation of a therapeutic cargo to TfR antibodies has also been explored, where fusion with compounds such as brain-derived neurotrophic factor or nerve growth factor correlated with indirect improvements in neuroprotection [116][117][118]. Because OX-26 recognizes only the rat TfR, murine cross-reactive 8D3 and R17-217 are additional anti-TfRs that have been generated and explored for their ability to delivery large molecules to the brain [115,119].…”

In Vivo Labeling of Brain Capillary Endothelial Cells after Intravenous Injection of Monoclonal Antibodies Targeting the Transferrin Receptor

“…However, the most numerous data were obtained with monoclonal antibodies (MAbs) targeting the insulin (Coloma et al, 2000;Zhang et al, 2003a) or transferrin receptors (TfR) Shi and Pardridge, 2000;Zhang et al, 2003b). These two receptors represent attractive targets because they populate BCECs throughout the BBB (Mash et al, 1990;Moos, 1996;Kissel et al, 1998), where they are expected to carry their bloodborne substrates into the brain through receptor-mediated transcytosis (Pardridge et al, 1987;Qian et al, 2002;Pardridge, 2007).…”

Alteration at translational but not transcriptional level of transferrin receptor expression following manganese exposure at the blood–CSF barrier in vitro

“…The TfR is located at the blood-brain barrier and the blood-CSF barrier, where it is responsible for the fluxes of iron in and out of brain; it also presents on the cell surface of neurons and neuroglia for cellular iron uptake (Burdo and Connor, 2001;Moos and Morgan, 2000). TfR is abundantly expressed in the choroid epithelia (Giometto et al, 1990;Kissel et al, 1998). At the cellular level, the proteins associated with iron homeostasis are post-transcriptionally regulated by binding or unbinding of iron regulatory proteins (IRPs) to mRNAs encoding TfR and ferritin whose sequences contain stem-loop structures, known as ironresponsive elements (IREs) (Beinert and Kennedy, 1993;Klausner et al, 1993).…”