Journal: Journal of Biomedical Science

Article Title: The ACE2 decoy receptor can overcome immune escape by rapid mutating SARS-CoV-2 variants and reduce cytokine induction and clot formation

doi: 10.1186/s12929-025-01156-4

Figure Lengend Snippet: Varied properties of Spike protein variants. A The expression of different Spike variants in 293 T-ACE2 Cells. Two days after transfection, the presence of various Spike protein variants in cell lysates was confirmed by immunoblotting. β-actin was used as a loading control. B Cell Fusion in 293 T-ACE2 Cells. Images showing how different Spike protein variants induced cell fusion and syncytia formation. Scale bars represent 150 µm. C Quantitative syncytia analysis. The measured areas of syncytia formation to quantify the extent of cell fusion. D Levels of different Spike protein variants expressed in another cell line, H1650-ACE2. E Syncytia formation in H1650-ACE2 Cells. Similar to panel B, but demonstrating syncytia formation in H1650-ACE2 cells. Scale bars represent 150 µm. F Cytotoxicity post-Spike transfection. The cytotoxic effects observed 48 h after transfecting different Spike variants into H1650-ACE2 cells, with Triton-X100 treated cells serving as the 100% cytotoxicity control. G , H Impact on PBMCs. After treating PBMCs for 24 h with supernatants from H1650-ACE2 cells transfected with various Spike variants for 48 h, the levels of inflammation markers IL-6 and TNF-α were measured. Data are presented as mean ± SD from three replicates. Statistical analysis was performed by One-Way ANOVA with multiple comparisons *P < 0.05

Article Snippet: For the ACE2-Fc treatment groups, trimeric Spike protein was pre-incubated for 15 min with ACE2-Fc alone, ACE2-Fc plus Spike antibody (Genetex), or ACE2-Fc plus the ACE2 catalytic inhibitor MLN-4760 (MedChemExpress), prior to mixing with plasma and initiating clot formation.

Techniques: Expressing, Transfection, Western Blot, Control

Journal: Journal of Biomedical Science

Article Title: The ACE2 decoy receptor can overcome immune escape by rapid mutating SARS-CoV-2 variants and reduce cytokine induction and clot formation

doi: 10.1186/s12929-025-01156-4

Figure Lengend Snippet: Blocking of pseudovirus entry by ACE2-Fc across different Spike variants. A Recognition by ACE2-Fc. Flow cytometry analysis showing the binding of ACE2-Fc, tagged with a fluorescent marker (FITC), to different Spike protein variants expressed on 293 T cells. Mouse IgG-FITC was used as an isotype control to validate the specificity of ACE2-Fc binding. B , C Inhibition of Pseudovirus Entry. These panels demonstrate the effectiveness of ACE2-Fc in blocking the entry of pseudoviruses into two types of cells: 293 T-ACE2 ( B ) and H1650-ACE2 ( C ). The results indicate that ACE2-Fc can prevent pseudovirus infection by interfering with the interaction between the Spike protein and the ACE2 receptor on the surface of target cells. Data are presented as mean ± SD from three replicates. Statistical analysis was performed by unpaired two-tail t-test. *P < 0.05

Article Snippet: For the ACE2-Fc treatment groups, trimeric Spike protein was pre-incubated for 15 min with ACE2-Fc alone, ACE2-Fc plus Spike antibody (Genetex), or ACE2-Fc plus the ACE2 catalytic inhibitor MLN-4760 (MedChemExpress), prior to mixing with plasma and initiating clot formation.

Techniques: Blocking Assay, Flow Cytometry, Binding Assay, Marker, Control, Inhibition, Infection

Journal: Journal of Biomedical Science

Article Title: The ACE2 decoy receptor can overcome immune escape by rapid mutating SARS-CoV-2 variants and reduce cytokine induction and clot formation

doi: 10.1186/s12929-025-01156-4

Figure Lengend Snippet: Inhibitory effects of ACE2-Fc on Spike-induced cell fusion and cytotoxicity. A Syncytia formation in 293 T-ACE2 Cells. ACE2-Fc inhibits the formation of syncytia induced by different Spike protein variants. The effectiveness of the inhibition is visually represented, with scale bars measuring 150 µm. B Quantitative analysis of GFP area. The quantitative results of the green fluorescent (GFP) area, which reflects the extent of syncytia formation. The calculations are based on a formula detailed in the Methods section of the study. C Syncytia reversal in H1650-ACE2 Cells. ACE2-Fc can reverse syncytia formation caused by different Spike variants in another cell type, H1650-ACE2. Scale bars represent 150 µm. D Reduction of cytotoxicity. ACE2-Fc reduces cytotoxicity observed 48 h after transfecting different Spike variants into H1650-ACE2 cells. E – F Reduction of cytokine induction. ACE2-Fc effectively reduces Delta and BQ.1 Spike meditated the induction of IL-6 and TNF-α in human PBMCs. Data are presented as mean ± SD from three replicates. Statistical analysis was performed by One-Way ANOVA with multiple comparisons ( B , D ) or unpaired two-tail t-test ( E , F ). *P < 0.05

Article Snippet: For the ACE2-Fc treatment groups, trimeric Spike protein was pre-incubated for 15 min with ACE2-Fc alone, ACE2-Fc plus Spike antibody (Genetex), or ACE2-Fc plus the ACE2 catalytic inhibitor MLN-4760 (MedChemExpress), prior to mixing with plasma and initiating clot formation.

Techniques: Inhibition

Journal: Journal of Biomedical Science

Article Title: The ACE2 decoy receptor can overcome immune escape by rapid mutating SARS-CoV-2 variants and reduce cytokine induction and clot formation

doi: 10.1186/s12929-025-01156-4

Figure Lengend Snippet: Inhibition of SARS-CoV-2 entry into host cells by ACE2-Fc. A Plaque assay inhibition. The ability of ACE2-Fc to inhibit infection by different SARS-CoV-2 variants using a plaque assay. The effectiveness of ACE2-Fc is compared to human IgG (hIgG), which serves as a baseline for inhibition. B Yield reduction assay. This assay was conducted to evaluate the inhibitory effects of ACE2-Fc on various coronavirus variants in H1650-ACE2 cells. The assay measures the reduction in the number of infectious virus particles as a result of ACE2-Fc treatment. C Plaque assay in Vero-E6 cells. This plaque assay quantifies the viral titer in the supernatant collected from the yield reduction assay. This method assesses the amount of virus that remains infectious after treatment with ACE2-Fc. Data are presented as mean ± SD from three replicates. Statistical analysis was conducted using an unpaired two-tail t-test. * P < 0.05, ** P < 0.01, *** P < 0.001. D Inhibition of nucleocapsid protein expression. The effect of ACE2-Fc on the expression of the Nucleocapsid protein across different variants. The results show a reduction in Nucleocapsid protein levels, indicating effective inhibition of virus replication by ACE2-Fc

Article Snippet: For the ACE2-Fc treatment groups, trimeric Spike protein was pre-incubated for 15 min with ACE2-Fc alone, ACE2-Fc plus Spike antibody (Genetex), or ACE2-Fc plus the ACE2 catalytic inhibitor MLN-4760 (MedChemExpress), prior to mixing with plasma and initiating clot formation.

Techniques: Inhibition, Plaque Assay, Infection, Virus, Expressing

Journal: Journal of Biomedical Science

Article Title: The ACE2 decoy receptor can overcome immune escape by rapid mutating SARS-CoV-2 variants and reduce cytokine induction and clot formation

doi: 10.1186/s12929-025-01156-4

Figure Lengend Snippet: Blocking of SARS-CoV-2 induced cytotoxicity, cytokine release and clot formation by ACE2-Fc. A The cytotoxicity in H1650-ACE2 cells. The cytotoxic effects observed in cells infected with different SARS-CoV-2 variants over 24 and 48 h. After the infection period, the supernatant was collected to measure cell damage, using Triton-X100 treated cells serving as the 100% cytotoxicity control. B Cytokine levels in PBMCs post-infection. After 48 h of infection in H1650-ACE2 cells, the supernatants were used to treat PBMCs, and the levels of IL-6 and TNF-α were measured. *Significant differences compared to the MOCK group. P < 0.05. C Inhibition of cytotoxicity by ACE2-Fc. Pre-treatment with ACE2-Fc significantly reduces the cytotoxic effects in H1650-ACE2 cells infected with various coronavirus variants 48 h post-infection. D Reduction of cytokine release by ACE2-Fc. ACE2-Fc treatment effectively decreases the release of IL-6 and TNF-α by PBMCs that were exposed to supernatants from infected H1650-ACE2 cells. Data are presented as mean ± SD from three replicates. Statistical analysis was performed by One-Way ANOVA with multiple comparisons *P < 0.05. E The turbidity of human plasma clot formation with D614G, Delta, and BA.5 spike. F – H The effect of ACE2-Fc treatment on plasma clot formation induced by the D614G ( F ), Delta ( G ), and BA.5 H Spike proteins. I Effect of ACE2-Fc co-treatment with Spike antibody on plasma clot formation. ( J ) Effect of ACE2-Fc co-treatment with the ACE2 catalytic inhibitor MLN-4760 on plasma clot formation. E – J show representative results, with similar trends observed in three independent experiments

Article Snippet: For the ACE2-Fc treatment groups, trimeric Spike protein was pre-incubated for 15 min with ACE2-Fc alone, ACE2-Fc plus Spike antibody (Genetex), or ACE2-Fc plus the ACE2 catalytic inhibitor MLN-4760 (MedChemExpress), prior to mixing with plasma and initiating clot formation.

Techniques: Blocking Assay, Infection, Control, Inhibition, Clinical Proteomics

Journal: Journal of Biomedical Science

Article Title: The ACE2 decoy receptor can overcome immune escape by rapid mutating SARS-CoV-2 variants and reduce cytokine induction and clot formation

doi: 10.1186/s12929-025-01156-4

Figure Lengend Snippet: Schematic diagram of the impact of SARS-CoV-2 variants and ACE2-Fc inhibition. This diagram illustrates the process of cell fusion induced by different SARS-CoV-2 variants, which leads to cytotoxicity and cytokine induction in host cells. It also shows how ACE2-Fc treatment can inhibit these effects. ACE2-Fc is highlighted as a therapeutic agent that effectively blocks the disease progression at multiple stages: preventing the virus from entering cells, reducing cell fusion, mitigating cell damage, and decreasing the release of inflammatory cytokines

Article Snippet: For the ACE2-Fc treatment groups, trimeric Spike protein was pre-incubated for 15 min with ACE2-Fc alone, ACE2-Fc plus Spike antibody (Genetex), or ACE2-Fc plus the ACE2 catalytic inhibitor MLN-4760 (MedChemExpress), prior to mixing with plasma and initiating clot formation.

Techniques: Inhibition, Biomarker Discovery, Virus