ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005


The Latest on X

Kidney Week

Please note that you are viewing an archived section from 2022 and some content may be unavailable. To unlock all content for 2022, please visit the archives.

Abstract: FR-PO015

Neutralization of the Omicron Variant of SARS-CoV-2 Is Effective by a Human and a Mouse Soluble ACE2 Protein

Session Information

Category: Coronavirus (COVID-19)

  • 000 Coronavirus (COVID-19)


  • Hassler, Luise, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
  • Nicolaescu, Vlad I., The University of Chicago, Chicago, Illinois, United States
  • Wysocki, Jan, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
  • Randall, Glenn, The University of Chicago, Chicago, Illinois, United States
  • Batlle, Daniel, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States

We have previously reported that ACE2 618-DDC-ABD, a soluble ACE2 protein with extended duration of action and increased binding affinity for SARS-CoV-2, provides lung and kidney protection in a lethal mouse model of SARS-CoV-2 infection. Moreover, we showed that this protein also neutralizes the gamma and delta variant SARS-CoV-2 infection in Vero E6 cells. As omicron is most prevalent SARS-CoV-2 variant we tested whether ACE2 618-DDC-ABD can also neutralize this variant and hypothesized that it is more sensitive to mouse ACE2 as well as human ACE2.


The omicron BA.1 SARS-CoV-2 strain was incubated with various concentrations of ACE2 618-DDC-ABD (0-180ug/ml) for 1 hour at 37°C. Human ACE2 1-740 and mouse ACE2 1-740 were used as controls at the same concentrations. These mixtures were then used to infect Vero E6 cells. Cells were allowed to grow for 3-4 days until a noticeable cytopathic effect was observed in control wells (0μg/ml soluble ACE2 proteins). Cell numbers were assessed by staining cells with crystal violet and reading absorbance of each well at 595 nm. Values were then normalized to the 0μg/ml control and expressed as a percentage of the mock (no virus) control wells.


ACE2 618-DDC-ABD (red) neutralized the omicron BA.1 variant at all concentrations tested and to a similar extent as native human soluble ACE2 1-740 (blue) used as control. Native mouse ACE2 1-740 (black) also neutralized infection completely at high concentrations while lower concentrations were less effective as compared to low concentrations of ACE2 618-DDC-ABD or human ACE2 1-740.


Soluble ACE2 618-DDC-ABD effectively neutralizes the omicron BA.1 variant of SARS-CoV-2 in Vero E6 cells at concentrations lower than those we have previously shown are required for gamma, delta and wildtype SARS-CoV-2. Moreover, the omicron BA.1 variant is sensitive to neutralization by soluble mouse ACE2.


  • NIDDK Support