AUTHOR=Pitino Marco , Fleites Laura A. , Shrum Lauren , Heck Michelle , Shatters Robert G. 

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

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2022.1045337

DOI=10.3389/fbioe.2022.1045337

ISSN=2296-4185

ABSTRACT=<p>Nanobodies<sup>®</sup> (V<sub>HH</sub> antibodies), are small peptides that represent the antigen binding domain, V<sub>HH</sub> of unique single domain antibodies (heavy chain only antibodies, HcAb) derived from camelids. Here, we demonstrate production of V<sub>HH</sub> nanobodies against the SARS-CoV-2 spike proteins in the solanaceous plant <italic>Nicotiana benthamiana</italic> 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.</p>