In the published article, there was an error in the legend for Figure 3 as published. The statistics style output rather than the significance levels was reported. The corrected legend appears below.
“Characterization of engineered human flACE2-Fc and trACE2–Fc fusion proteins. (A) Size-exclusion chromatography (SEC) of IEX fractions containing flACE2-Fc-WT using a Superose 6 column, with oligomeric, monomeric forms and low mw impurities (†) indicated; and (B) SEC of IEX fractions containing flACE2-Fc H429Y, showing the high proportion of oligomeric species. (C–F) Biolayer interferometry (BLI) analysis of ACE2-Fc proteins which were immobilized on anti-human Fc (BLI) sensors and reacted with the indicated concentrations of RBD. The dissociation constants, KD (nM), are derived from global fitting of the association and dissociation curves to a Langmuir binding model. The ACE2-Fc proteins were, (C) trACE2-Fc WT (D) flACE2-Fc WT, (E) flACE2-Fc H429F and (F) the RBD binding-enhanced triple mutant of ACE2 fused to Fc; EflACE2-Fc WT (representative of n = 2 independent experiments). (G) Native Gel-shift analysis of ACE2-Fc proteins (1 μg, ~ 5 pmol) alone or combined with SARS-CoV-2 spike RBD-Ig (0.5 μg, ~ 5 pmol) and analyzed by native PAGE. The resulting shift in size of the proteins in the mixtures demonstrated the formation of ACE2-Fc: Cov2-RBD complexes. (H) Binding of different formats of ACE2-Fc-WT, and their Fc variants to immobilized RBD-Ig was determined by ELISA. EC50 (nM) values are from agonist versus response curve fits, mean ± SD, n is indicated by individual symbols for each independent experiment. One-way ANOVA with Dunnett’s multiple comparisons test, p > 0.05 (ns), ≤ 0.05 (*), ≤ 0.01 (**), ≤ 0.0001 (****).”
In the published article, there was an error in the legend for Figure 4 as published. The statistics style output rather than the significance levels was reported. The corrected legend appears below.
“(A-C) SARS-CoV-2 neutralization potency of ACE2-Fc fusion proteins is increased by both the ACE2 scaffold and the H429Y Fc mutation. Neutralization potencies of the ACE2 enzymatic ectodomain polypeptide (trACE2) and the three formats of ACE2-Fc-WT fusion and variant proteins were determined by titration of the cytopathic effect to endpoint in a micro-neutralization assay. The fusion proteins were (A) trACE2-Fc-WT, (B) flACE2-Fc-WT and (C) EflACE2-Fc-WT, incorporating triple mutation of ACE2 engineered (43) for enhanced affinity to RBD and their Fc variants (Eu numbering), E430G, G; H429F, F; H429Y oligomers on SEC, Yog; and H429Y monomers on SEC, Ymn. A further variant trACE2-Fc fusion protein is the glycan-modified trACE2-Fc-kif produced in the presence of kifunensine. Mean ± SEM, one-way ANOVA with Dunnett’s multiple comparisons test, p > 0.05 (ns), ≤ 0.05 (*), ≤ 0.01 (**), independent experiments (n) are indicated as individual symbols.”
In the published article, there was an error in the legend for Figure 5 as published. The statistics style output rather than the significance levels was reported. The corrected legend appears below.
“FcγR and complement dependent effector functions of the ACE2-Fc decoy proteins. (A) Activation of FcγRIIIa by ACE2-Fc proteins. ACE2-Fc proteins activated FcγRIIIa, except for the Fc H429Y mutants which failed to stimulate in any ACE2 format either as oligomeric or monomeric forms. Ramos-S target cells were opsonized with trACE2-Fc, flACE2-Fc and EflACE2-Fc, WT and Fc variants, including H429F, F; H429Y, Y; E430G, G or trACE2-Fc-kif, produced from trACE2-Fc WT in 293Expi cells in the presence of the mannosidase inhibitor kifunensine. In some experiments Ramos-S target cells were separately opsonized with Rituximab, RIT. These opsonized targets were incubated with FcγRIIIa/NF-κB-RE nanoluciferase reporter cells and FcγRIIIa activation measured by the induction of nanoluciferase (RLU). Activation data (Supplementary Figures S1B, C) were fitted to agonist response curves to estimate EC50(nM); nd, not determined as there was insufficient activity for the data to be fitted. EC50 values from the curve fits are shown. Mean ± SEM, n is indicated by individual symbols for each independent experiment, one-way ANOVA with Dunnett’s multiple comparisons test, comparing to trACE2-Fc WT. p > 0.05 (ns), ≤ 0.05 (*), ≤ 0.01 (**), ≤ 0.001 (***), ≤ 0.0001 (****). (B) H429F, and E430G Fc mutant ACE2-Fc proteins are potent mediators of complement lysis of SARS-CoV-2 S expressing cells. Flow cytometric analysis of complement-dependent cytotoxicity (CDC) of opsonized Ramos-S cells was determined in the presence of a 1/3 dilution of a pool of normal human serum (from >5 individuals) as a source of complement. Plots are mean ± SEM, n = 3 independent experiments. Two-way ANOVA with Dunnett’s multiple comparisons test comparing to trACE2-Fc-WT for main column effect, p > 0.05 (ns), ≤ 0.01 (**), ≤ 0.0001 (****). EC50 (nM) values are mean ± SEM each from 3 curve fits.”
The authors apologize for these errors and state that they do not change the scientific conclusions of the article in any way. The original article has been updated.
Statements
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
Summary
Keywords
coronavirus, SARS-CoV-2, COVID-19, ACE2-Fc, neutralization, antibody effector function, ADCC, complement
Citation
Wines BD, Kurtovic L, Trist HM, Esparon S, Lopez E, Chappin K, Chan L-J, Mordant FL, Lee WS, Gherardin NA, Patel SK, Hartley GE, Pymm P, Cooney JP, Beeson JG, Godfrey DI, Burrell LM, van Zelm MC, Wheatley AK, Chung AW, Tham W-H, Subbarao K, Kent SJ and Hogarth PM (2023) Corrigendum: Fc engineered ACE2-Fc is a potent multifunctional agent targeting SARS-CoV2. Front. Immunol. 13:1122516. doi: 10.3389/fimmu.2022.1122516
Received
13 December 2022
Accepted
14 December 2022
Published
10 January 2023
Approved by
Frontiers Editorial Office, Frontiers Media SA, Switzerland
Volume
13 - 2022
Updates
Copyright
© 2023 Wines, Kurtovic, Trist, Esparon, Lopez, Chappin, Chan, Mordant, Lee, Gherardin, Patel, Hartley, Pymm, Cooney, Beeson, Godfrey, Burrell, van Zelm, Wheatley, Chung, Tham, Subbarao, Kent and Hogarth.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: P. Mark Hogarth, mark.hogarth@burnet.edu.au
This article was submitted to Viral Immunology, a section of the journal Frontiers in Immunology
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.