Membrane Fusion Mediated Targeted Cytosolic Drug Delivery Through scFv Engineered Sendai Viral Envelopes

Curr Mol Med. 2015;15(4):386-400. doi: 10.2174/1566524015666150505155949.

Abstract

Antibody targeted cytoplasmic delivery of drugs is difficult to achieve as antigen-antibody interaction results in the payload being directed to the endosomal compartment. However, Sendai viral envelopes can bring about cytoplasmic delivery due to F-protein mediated membrane fusion. In this study we have generated and fused a recombinant scFv directed to the onco-fetal antigen, the Placental isozyme of Alkaline Phosphatase (PAP) with the trans-membrane and part of the cytoplasmic domain of the Sendai F protein (F(TMC)). Reconstituted virosomes, having both the fusion protein as well as the native F-protein were able to specifically bind and deliver drugs to PAP expressing cells. About 75% of the delivery was cytoplasmic in nature. Hence, this immuno-virosome, which is devoid of the comparatively more toxic HN protein, has the novel ability to combine specific antibody mediated targeting with cytoplasmic delivery. The scFv ensured specific binding to PAP expressing cells, without cross reacting with the other isozymes of alkaline phosphatase. The advantages of cytoplasmic delivery would include reduced degradation and lowered immunogenicity of the payload and carrier. The ubiquitous expression of PAP on a variety of cancers like seminoma, choriocarcinoma, cervical and breast cancers also suggests its potential usefulness in a number of malignancies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / genetics
  • Alkaline Phosphatase / immunology*
  • Alkaline Phosphatase / metabolism
  • Animals
  • Antibiotics, Antineoplastic / pharmacology
  • Antibodies, Monoclonal / immunology
  • CHO Cells
  • Cell Line, Tumor
  • Cricetinae
  • Cricetulus
  • Cytoplasm / virology
  • Doxorubicin / pharmacology
  • Drug Delivery Systems / methods*
  • Fluorescein-5-isothiocyanate / metabolism
  • GPI-Linked Proteins / genetics
  • GPI-Linked Proteins / immunology
  • GPI-Linked Proteins / metabolism
  • HeLa Cells
  • Humans
  • Isoenzymes / genetics
  • Isoenzymes / immunology*
  • Isoenzymes / metabolism
  • Membrane Fusion / physiology
  • Peptide Library
  • Sendai virus / genetics
  • Sendai virus / metabolism*
  • Staining and Labeling
  • Viral Envelope Proteins / genetics
  • Viral Envelope Proteins / metabolism
  • Viral Fusion Proteins / genetics
  • Viral Fusion Proteins / immunology*
  • Viral Fusion Proteins / metabolism

Substances

  • Antibiotics, Antineoplastic
  • Antibodies, Monoclonal
  • GPI-Linked Proteins
  • Isoenzymes
  • Peptide Library
  • Viral Envelope Proteins
  • Viral Fusion Proteins
  • Doxorubicin
  • Alkaline Phosphatase
  • alkaline phosphatase, placental
  • Fluorescein-5-isothiocyanate