Biology subjects

Wysocki, J.

Publications and source records attributed to Wysocki, J..

3 recordsLinked to original sources

bioRxiv2021

A novel soluble ACE2 protein totally protects from lethal disease caused by SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) uses full-length angiotensin converting enzyme 2 (ACE2), which is membrane bound, as its initial cell contact receptor preceding viral entry. Here we report a human soluble ACE2 variant fused with a 5kD albumin binding domain (ABD) and bridged via a dimerization motif hinge-like 4-cysteine dodecapeptide, which we term ACE2 1-618-DDC-ABD. This protein is enzymatically active, has increased duration of action in vivo conferred by the ABD-tag, and displays 20-30-fold higher binding affinity to the SARS-CoV-2 receptor binding domain than its des-DDC monomeric form (ACE2 1-618-ABD) due to DDC-linked dimerization. ACE2 1-618-DDC-ABD was administered for 3 consecutive days to transgenic k18-hACE2 mice, a model that develops lethal SARS-CoV-2 infection, to evaluate the preclinical preventative/ therapeutic value for COVID-19. Mice treated with ACE2 1-618-DDC-ABD developed a mild to moderate disease for the first few days assessed by a clinical score and modest weight loss. The untreated control animals, by contrast, became severely ill and had to be sacrificed by day 6/7 and lung histology revealed extensive pulmonary alveolar hemorrhage and mononuclear infiltrates. At 6 days, mortality was totally prevented in the treated group, lung histopathology was improved and viral titers markedly reduced. This demonstrates for the first time in vivo the preventative/ therapeutic potential of a novel soluble ACE2 protein in a preclinical animal model.

pathology↗

bioRxiv2020

Circulating ACE2-expressing Exosomes Block SARS-CoV-2 Virus Infection as an Innate Antiviral Mechanism

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the coronavirus disease 2019 (COVID-19) with innate and adaptive immune response triggered in such patients by viral antigens. Both convalescent plasma and engineered high affinity human monoclonal antibodies have shown therapeutic potential to treat COVID-19. Whether additional antiviral soluble factors exist in peripheral blood remain understudied. Herein, we detected circulating exosomes that express the SARS-CoV-2 viral entry receptor angiotensin-converting enzyme 2 (ACE2) in plasma of both healthy donors and convalescent COVID-19 patients. We demonstrated that exosomal ACE2 competes with cellular ACE2 for neutralization of SARS-CoV-2 infection. ACE2-expressing (ACE2+) exosomes blocked the binding of the viral spike (S) protein RBD to ACE2+ cells in a dose dependent manner, which was 400- to 700-fold more potent than that of vesicle-free recombinant human ACE2 extracellular domain protein (rhACE2). As a consequence, exosomal ACE2 prevented SARS-CoV-2 pseudotype virus tethering and infection of human host cells at a 50-150 fold higher efficacy than rhACE2. A similar antiviral activity of exosomal ACE2 was further demonstrated to block wild-type live SARS-CoV-2 infection. Of note, depletion of ACE2+ exosomes from COVID-19 patient plasma impaired the ability to block SARS-CoV-2 RBD binding to host cells. Our data demonstrate that ACE2+ exosomes can serve as a decoy therapeutic and a possible innate antiviral mechanism to block SARS-CoV-2 infection.

immunology↗

bioRxiv2020

Kidney and Lung ACE2 expression after an ACE inhibitor or an Ang II receptor blocker: implications for COVID-19

BackgroundThere have been concerns that ACE inhibitors and Ang II receptor blockers may cause an increase in ACE2, the main receptor for SARs-CoV-2. MethodsKidneys from two genetic models of kidney ACE ablation and mice treated with captopril or telmisartan were used to examine ACE2 in isolated kidney and lung membranes. ResultsIn a global ACE KO mice, ACE2 protein abundance in kidney membranes was reduced to 42 % of wild type, p < 0.05. In ACE 8/8 mice that over-expresses cardiac ACE protein but also has no kidney ACE expression, ACE2 protein in kidney membranes was also decreased (38 % of the WT, p<0.01). In kidney membranes from mice that received captopril or telmisartan for 2 weeks there was a reduction in ACE2 protein (37% in captopril treated p<0.01) and 76% in telmisartan treated p <0.05). In lung membranes the expression of ACE2 was very low and not detected by western blotting but no significant differences in terms of ACE2 activity could be detected in mice treated with captopril (118% of control) or telmisartan (93% of control). ConclusionsGenetic kidney ACE protein deficiency, suppressed enzymatic activity by Captopril or blockade of the AT1 receptor with telmisartan are all associated with a decrease in ACE2 in kidney membranes. ACE2 protein in kidney or lungs is decreased or unaffected by RAS blockers indicating that these medications can not pose a risk for SARS-CoV-2 infection related to amplification of ACE2 at these two target sites for viral entry.

physiology↗