The study of degradation mechanisms of glyco-engineered plant produced anti-rabies monoclonal antibodies E559 and 62-71-3

PLoS One. 2018 Dec 20;13(12):e0209373. doi: 10.1371/journal.pone.0209373. eCollection 2018.

Abstract

Rabies is an ancient and neglected zoonotic disease caused by the rabies virus, a neurotropic RNA virus that belongs to the Rhabdoviridae family, genus Lyssavirus. It remains an important public health problem as there are cost and health concerns imposed by the current human post exposure prophylaxis therapy. The use of monoclonal antibodies (mAbs) is therefore an attractive alternative. Rabies mostly affects people that reside in resource-limited areas where there are occasional failures in the cold-chain. These environmental changes may upset the stability of the mAbs. This study focused on mAbs 62-71-3 and E559; their structures, responses to freeze/thaw (F/T) and exposure to reactive oxygen species were therefore studied with the aid of a wide range of biophysical and in silico techniques in order to elucidate their stability and identify aggregation prone regions. E559 was found to be less stable than 62-71-3. The complementarity determining regions (CDR) contributed the most to its instability, more specifically: peptides 99EIWD102 and 92ATSPYT97 found in CDR3, Trp33 found in CDR1 and the oxidised Met34. The constant region "158SWNSGALTGHTFPAVL175" was also flagged by the special aggregation propensity (SAP) tool and F/T experiments to be highly prone to aggregation. The E559 peptides "4LQESGSVL11 from the heavy chain and 4LTQSPSSL11 from the light chain, were also highly affected by F/T. These residues may serve as good candidates for mutation, in the aim to bring forward more stable therapeutic antibodies, thus paving a way to a more safe and efficacious antibody-based cocktail treatment against rabies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / chemistry*
  • Antibodies, Monoclonal / genetics
  • Antibodies, Monoclonal / metabolism
  • Antibodies, Monoclonal / therapeutic use
  • Antibodies, Viral / chemistry*
  • Antibodies, Viral / genetics
  • Antibodies, Viral / metabolism
  • Antibodies, Viral / therapeutic use
  • Cold Temperature / adverse effects
  • Complementarity Determining Regions / chemistry
  • Complementarity Determining Regions / genetics
  • Computer Simulation
  • Drug Stability
  • Drug Storage
  • Humans
  • Neutralization Tests
  • Nicotiana / genetics
  • Nicotiana / metabolism
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism
  • Protein Engineering / methods
  • Proteolysis
  • Rabies / immunology
  • Rabies / therapy*
  • Rabies / virology
  • Rabies virus / immunology*
  • Reactive Oxygen Species / chemistry

Substances

  • 62-71-3 monoclonal antibody
  • Antibodies, Monoclonal
  • Antibodies, Viral
  • Complementarity Determining Regions
  • Reactive Oxygen Species

Grants and funding

This work was was funded by the National Research Foundation (http://www.nrf.ac.za/): Professional Development Programme (DST-NRF: PDP), Council for Scientific and Industrial Research (CSIR) (Grant 78993). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.