Endosomal escape efficiency of fusogenic B18 and B55 peptides fused with anti-EGFR single chain Fv as estimated by nuclear translocation.
Although monoclonal antibodies have been used not only as analytical tools but also as biologic therapeutics, they cannot target intracellular proteins due to their large molecular size and low membrane permeability, which limit their applications. During previous attempts to delivery antibodies intracellularly, the low efficiency of escape from endosomes to the cytosol reduced the bioavailability of antibodies or antibody-conjugated effectors. Recently, we found that the fusogenic peptides (FPs) B18 and B55 from bindin, a sea urchin gamete recognition protein, facilitated the endosomal escape of FP-fused enhanced green fluorescent protein (eGFP) and/or of co-administered cargos such as dextrans [Niikura et al. A fusogenic peptide from a sea urchin fertilization protein promotes intracellular delivery of biomacromolecules by facilitating endosomal escape. J.


METHODS
Release 2015;212:85-93]. In this study, we constructed FP-fused anti-epidermal growth factor receptor (EGFR) single-chain Fv (αEGFR[scFv]) proteins and evaluated their endosomal escape efficiency by utilizing a nuclear localization signal). When the FP-fused αEGFR[scFv] proteins were incubated with A431 cells, the estimated endosomal escape efficiency of αEGFR[scFv]-B18 was significantly higher than that of αEGFR[scFv] alone, suggesting that the B18 peptide facilitates endosomal escape of the conjugated scFv in cis. Moreover, αEGFR[scFv]-B55 promoted the intracellular uptake of co-administered eGFP and dextrans in trans. These results imply that B18- and B55-fused antibodies may be useful for the cell-specific intracellular delivery of biomacromolecules.
Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan.
Keisuke
K
Niikura
Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan.
Kenichi
K
Horisawa
Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan doi@bio.keio.ac.jp.
Nobuhide
N
Doi
D021581:Active Transport, Cell Nucleus; D003600:Cytosol / Q000378:metabolism; D003911:Dextrans / Q000378:metabolism; D016503:Drug Delivery Systems; D011992:Endosomes / Q000378:metabolism*; D066246:ErbB Receptors / Q000276:immunology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D019913:Nuclear Localization Signals / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D057127:Single-Chain Antibodies / Q000008:administration & dosage* / Q000493:pharmacokinetics
D003911:Dextrans; D019913:Nuclear Localization Signals; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D057127:Single-Chain Antibodies; C035027:egg surface sperm receptor; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C512478:EGFR protein, human; D066246:ErbB Receptors
antibody engineering; endosomal escape; fusogenic peptide; intracellular delivery; nuclear translocation