A transgene-encoded cell surface polypeptide for selection, in vivo tracking, and ablation of engineered cells

X Wang, WC Chang, CLW Wong… - Blood, The Journal …, 2011 - ashpublications.org
X Wang, WC Chang, CLW Wong, D Colcher, M Sherman, JR Ostberg, SJ Forman…
Blood, The Journal of the American Society of Hematology, 2011ashpublications.org
An unmet need in cell engineering is the availability of a single transgene encoded,
functionally inert, human polypeptide that can serve multiple purposes, including ex vivo cell
selection, in vivo cell tracking, and as a target for in vivo cell ablation. Here we describe a
truncated human EGFR polypeptide (huEGFRt) that is devoid of extracellular N-terminal
ligand binding domains and intracellular receptor tyrosine kinase activity but retains the
native amino acid sequence, type I transmembrane cell surface localization, and a …
Abstract
An unmet need in cell engineering is the availability of a single transgene encoded, functionally inert, human polypeptide that can serve multiple purposes, including ex vivo cell selection, in vivo cell tracking, and as a target for in vivo cell ablation. Here we describe a truncated human EGFR polypeptide (huEGFRt) that is devoid of extracellular N-terminal ligand binding domains and intracellular receptor tyrosine kinase activity but retains the native amino acid sequence, type I transmembrane cell surface localization, and a conformationally intact binding epitope for pharmaceutical-grade anti-EGFR monoclonal antibody, cetuximab (Erbitux). After lentiviral transduction of human T cells with vectors that coordinately express tumor-specific chimeric antigen receptors and huEGFRt, we show that huEGFRt serves as a highly efficient selection epitope for chimeric antigen receptor+ T cells using biotinylated cetuximab in conjunction with current good manufacturing practices (cGMP)-grade anti-biotin immunomagnetic microbeads. Moreover, huEGFRt provides a cell surface marker for in vivo tracking of adoptively transferred T cells using both flow cytometry and immunohistochemistry, and a target for cetuximab-mediated antibody-dependent cellular cytotoxicity and in vivo elimination. The versatility of huEGFRt and the availability of pharmaceutical-grade reagents for its clinical application denote huEGFRt as a significant new tool for cellular engineering.
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