RecombiMAb anti-rat/mouse CD71 (TfR1)

About RecombiMAb anti-rat/mouse CD71 (TfR1)

The OX-26-CP079 monoclonal antibody is a recombinant version of the original OX-26 antibody that contains the Fc-silencing mutations in the heavy chain rendering it unable to bind endogenous murine Fcγ receptors or C1q. The LALA-PG mutations prevent antibody-dependent, cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). The LALA-PG variant has significantly reduced effector function, C1q binding and C3 fixation compared to other common silencing mutations such as the LALA and DANG variants while retaining favorable biophysical and manufacturing properties. Recent studies have demonstrated that administration of anti-TfR1 antibodies with Fc effector function in mice resulted in acute clinical signs of toxicity and a decrease in reticulocyte count. These negative effects were eliminated through Fc-silencing. The OX-26 monoclonal antibody reacts with rat and mouse CD71, also known as transferrin receptor protein 1 (TfR1). CD71 is a type II homodimeric transmembrane glycoprotein which is expressed on the surface of proliferating cells, reticulocytes, and erythroid precursors. CD71 plays a role in the control of cellular proliferation and is required for iron import from transferrin into cells by endocytosis. CD71 is overexpressed on many different types of cancer cells and expression level correlates with advanced stage and/or poorer prognosis in several cancers, including solid cancers. Elevated levels of CD71 expression on malignant cells, together with its extracellular accessibility, ability to internalize, and central role in cancer cell pathology make this receptor an attractive target for antibody-mediated therapy. In addition, cells of the vascular endothelium of brain capillaries that compose the blood-brain barrier (BBB) also express high levels of CD71 allowing for receptor-mediated transcytosis of large biomolecules into the brain. OX-26 has been used as a BBB transporter in rats and mice and is suitable for studying CD71 expression and iron uptake into different tissues. The OX-26 antibody binds to a distinct extracellular epitope on TfR that does not compete for binding with the natural ligand Tf or iron uptake. The OX-26 antibody is often used to transport conjugated drugs across the BBB in experimental models.