TY - JOUR
T1 - Anthrax Protective Antigen Retargeted with Single-Chain Variable Fragments Delivers Enzymes to Pancreatic Cancer Cells
AU - Loftis, Alexander R.
AU - Santos, Michael S.
AU - Truex, Nicholas L.
AU - Biancucci, Marco
AU - Satchell, Karla J.F.
AU - Pentelute, Bradley L.
N1 - Funding Information:
Financial support for this work was provided by an NSF CAREER grant (CHE‐1351807 to B.L.P.), the MIT/NIGMS Biotechnology Training Program (T32 GM008334‐28 to A.R.L.), an NIH postdoctoral fellowship (F32 CA239362 to N.L.T.), a PanCan/FNLCR KRAS postdoctoral fellowship (to M.B.), NIH grant R01 AI092825 and the Northwestern Medicine Catalyst Fund (to K.J.F.S.).
Funding Information:
Financial support for this work was provided by an NSF CAREER grant (CHE-1351807 to B.L.P.), the MIT/NIGMS Biotechnology Training Program (T32 GM008334-28 to A.R.L.), an NIH postdoctoral fellowship (F32 CA239362 to N.L.T.), a PanCan/FNLCR KRAS postdoctoral fellowship (to M.B.), NIH grant R01 AI092825 and the Northwestern Medicine Catalyst Fund (to K.J.F.S.).
Publisher Copyright:
© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/10/1
Y1 - 2020/10/1
N2 - The nontoxic, anthrax protective antigen/lethal factor N-terminal domain (PA/LFN) complex is an effective platform for translocating proteins into the cytosol of cells. Mutant PA (mPA) was recently fused to epidermal growth factor (EGF) to retarget delivery of LFN to cells bearing EGF receptors (EGFR), but the requirement for a known cognate ligand limits the applicability of this approach. Here, we render practical protective antigen retargeting to a variety of receptors with mPA single-chain variable fragment (scFv) fusion constructs. Our design enables the targeting of two pancreatic cancer-relevant receptors, EGFR and carcinoembryonic antigen. We demonstrate that fusion to scFvs does not disturb the basic functions of mPA. Moreover, mPA−scFv fusions enable cell-specific delivery of diphtheria toxin catalytic domain and Ras/Rap1-specific endopeptidase to pancreatic cancer cells. Importantly, mPA−scFv fusion-based treatments display potent cell-specific toxicity in vitro, opening fundamentally new routes toward engineered immunotoxins and providing a potential solution to the challenge of targeted protein delivery to the cytosol of cancer cells.
AB - The nontoxic, anthrax protective antigen/lethal factor N-terminal domain (PA/LFN) complex is an effective platform for translocating proteins into the cytosol of cells. Mutant PA (mPA) was recently fused to epidermal growth factor (EGF) to retarget delivery of LFN to cells bearing EGF receptors (EGFR), but the requirement for a known cognate ligand limits the applicability of this approach. Here, we render practical protective antigen retargeting to a variety of receptors with mPA single-chain variable fragment (scFv) fusion constructs. Our design enables the targeting of two pancreatic cancer-relevant receptors, EGFR and carcinoembryonic antigen. We demonstrate that fusion to scFvs does not disturb the basic functions of mPA. Moreover, mPA−scFv fusions enable cell-specific delivery of diphtheria toxin catalytic domain and Ras/Rap1-specific endopeptidase to pancreatic cancer cells. Importantly, mPA−scFv fusion-based treatments display potent cell-specific toxicity in vitro, opening fundamentally new routes toward engineered immunotoxins and providing a potential solution to the challenge of targeted protein delivery to the cytosol of cancer cells.
KW - anthrax toxin
KW - intracellular delivery
KW - pancreatic cancer
KW - protein therapeutics
KW - scFv
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UR - http://www.scopus.com/inward/citedby.url?scp=85091800907&partnerID=8YFLogxK
U2 - 10.1002/cbic.202000201
DO - 10.1002/cbic.202000201
M3 - Article
C2 - 32369652
AN - SCOPUS:85091800907
SN - 1439-4227
VL - 21
SP - 2772
EP - 2776
JO - ChemBioChem
JF - ChemBioChem
IS - 19
ER -
