AUTHOR=Liu Jinny L. , Webb Emily M. , Zabetakis Dan , Burke Crystal W. , Gardner Christina L. , Glass Pamela J. , Legler Patricia M. , Weger-Lucarelli James , Anderson George P. , Goldman Ellen R. 

TITLE=Stabilization of a Broadly Neutralizing Anti-Chikungunya Virus Single Domain Antibody

JOURNAL=Frontiers in Medicine

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2021.626028

DOI=10.3389/fmed.2021.626028

ISSN=2296-858X

ABSTRACT=<p>A single domain antibody (clone CC3) previously found to neutralize a vaccine strain of the chikungunya virus (PRNT<sub>50</sub> = 2. 5 ng/mL) was found to be broadly neutralizing. Clone CC3 is not only able to neutralize a wild-type (WT) strain of chikungunya virus (CHIKV), but also neutralizes WT strains of Mayaro virus (MAYV) and Ross River virus (RRV); both arthralgic, Old World alphaviruses. Interestingly, CC3 also demonstrated a degree of neutralizing activity against the New World alphavirus, Venezuelan equine encephalitis virus (VEEV); albeit both the vaccine strain, TC-83, and the parental, WT Trinidad donkey strain had PRNT<sub>50</sub> values ~1,000-fold higher than that of CHIKV. However, no neutralization activity was observed with Western equine encephalitis virus (WEEV). Ten CC3 variants designed to possess a range of isoelectric points, both higher and lower, were constructed. This approach successfully identified several lower pI mutants which possessed improved thermal stabilities by as much as 10°C over the original CC3 (T<sub>m</sub> = 62°C), and excellent refolding abilities while maintaining their capacity to bind and neutralize CHIKV.</p>