Plant production of high affinity nanobodies that block SARS-CoV-2 spike protein binding with its receptor, human angiotensin converting enzyme

Marco Pitino; Laura A Fleites; Lauren Shrum; Michelle Heck; Robert G Shatters Jr

doi:10.3389/fbioe.2022.1045337

Plant production of high affinity nanobodies that block SARS-CoV-2 spike protein binding with its receptor, human angiotensin converting enzyme

Front Bioeng Biotechnol. 2022 Dec 23:10:1045337. doi: 10.3389/fbioe.2022.1045337. eCollection 2022.

Authors

Marco Pitino¹, Laura A Fleites¹, Lauren Shrum¹, Michelle Heck², Robert G Shatters Jr³

Affiliations

¹ AgroSource, Inc, Jupiter, FL, United States.
² Emerging Pests and Pathogens Research Unit, USDA Agricultural Research Service, Ithaca, NY, United States.
³ U.S. Horticultural Research Laboratory, Subtropical Insects and Horticulture Research Unit, USDA Agricultural Research Service, Fort Pierce, FL, United States.

Abstract

Nanobodies^® (V_HH antibodies), are small peptides that represent the antigen binding domain, V_HH of unique single domain antibodies (heavy chain only antibodies, HcAb) derived from camelids. Here, we demonstrate production of V_HH nanobodies against the SARS-CoV-2 spike proteins in the solanaceous plant Nicotiana benthamiana through transient expression and their subsequent detection verified through western blot. We demonstrate that these nanobodies competitively inhibit binding between the SARS-CoV-2 spike protein receptor binding domain and its human receptor protein, angiotensin converting enzyme 2. There has been significant interest and a number of publications on the use of plants as biofactories and even some reports of producing nanobodies in plants. Our data demonstrate that functional nanobodies blocking a process necessary to initiate SARS-CoV-2 infection into mammalian cells can be produced in plants. This opens the alternative of using plants in a scheme to rapidly respond to therapeutic needs for emerging pathogens in human medicine and agriculture.

Keywords: ACE2; SARS-CoV-2; VHH; biofactory; competitive ELISA; nanobody; plant; plant cell culture.

At least a portion of this work is authored by Michelle Heck and Robert G. Shatters Jr on behalf of the U.S. Government and as regards Dr. Heck, Dr. Shatters and the U.S. Government, is not subject to copyright protection in the United States. Foreign and other copyrights may apply.