calu-6  (ATCC)

Journal: iScience

Article Title: CGM23 corresponds to a pan-coronavirus lipopeptide inhibitor potently inhibiting virion fusion

doi: 10.1016/j.isci.2026.115334

Figure Lengend Snippet: Peptide design and evaluation (A) Schematic representation of SARS-CoV-2 spike protein and amino acid sequences of HR2 peptides from SARS-CoV-2 and EK1 (HCoV-OC43 HR2 derived peptide). N , N-terminus ; C , C-terminus ; S1/S2 , cleavage site at S1/S2 boundary ; RBD , receptor-binding domain ; HR1 , heptad repeat 1 ; HR2 , heptad repeat 2 ; HR2P , heptad repeat 2 peptide. Syncytia assay. Left: GFP- and spike-expressing 293T cells were co-cultured with RFP- and ACE2-expressing Calu-6 cells for 16 h in the presence or absence of peptides. Center: double-positive cells (white arrows) indicative of syncytia formation are frequent in the presence of the scrambled EK1 peptide (Ⅰ) but not in the presence of CGM23 (Ⅱ) (100 nM). Right: quantification of syncytia formation in the presence of the scrambled EK1 peptide (top) or CGM23 (bottom) relative to mock treatment. (B) Sequence, N- and C-terminal modifications and IC 50 of the 15 peptides with IC 50 s < 10 nM in the syncytia assay. CoV-2, SARS-CoV-2; N-term, N-terminus; C-term, C-terminus. IC 50 data are means of samples from a representative experiment. Ac, acetylation; PPA, 4-phenylpropanoic acid; PBA, 4-phenylbutanonic acid. (C) Correlation between IC 50 values in the pseudotyped SARS-CoV-2 spike virion assay and live SARS-CoV2 virus infection assay for the 15 peptides with IC 50 values below 10 nM in the syncytia assay. Statistical analysis was performed using Spearman’s rank test. (D and E) Dose-dependent inhibitory activity of CGM23 and EK1C4 relative to CG167 (EK1 scrambled peptide with EK1C4 lipidation) in the pseudotyped SARS-CoV2 spike virion assay (D) and live SARS-CoV2 infection assay (E). IC 50, half-maximal inhibitory concentration.

Article Snippet: Live virus experiments were performed with Calu-6 epithelial cells (ATCC HTB-56) stably expressing human Angiotensin Converting Enzyme 2 (ACE2) (OriGene, RC08442) as target cells.

Techniques: Derivative Assay, Binding Assay, Expressing, Cell Culture, Sequencing, Virus, Infection, Activity Assay, Concentration Assay

Journal: iScience

Article Title: CGM23 corresponds to a pan-coronavirus lipopeptide inhibitor potently inhibiting virion fusion

doi: 10.1016/j.isci.2026.115334

Figure Lengend Snippet: In vivo prophylactic and therapeutic efficacy of CGM23 against SARS-CoV-2 live virus in mice (A) The SARS-CoV-2 outgrowth assay. Lung homogenates were collected 2 days post viral infection (DPI) combined with intranasal administration of CGM23 and EK1C4 (12.5 μg, 0.865 mg/kg). (B) Diluted lung homogenates were added to Calu-6-ACE2 cells and infection titers were measured by the luciferase assay 48 h later. CG167, EK1 scrambled peptide with EK1C4 lipidation. Data presented correspond to mean ± SD. ∗ p < 0.05. Statistical analysis was performed using one-way ANOVA followed by Tukey’s post hoc test. (C) Histopathological findings of mouse lungs at 2 days after virus inoculation. Images are shown clockwise starting from the top left: CG167 group, EK1C4 group, non-infected group, and CGM23 group. Lung sections were stained with anti-spike antibody (green) and anti-MAC-2 antibody (magenta) and DAPI (blue). Scale bars, 100μm. (D and E) Quantitative analysis of lung histopathological findings for each group. Data shown represent means ± SD. (F) Therapeutic treatment. CGM23 and EK1C4 were administered intranasally (12.5 μg, 0.865 mg/kg; 25 μg, 1.73 mg/kg) 8 h after SARS-CoV-2 inoculation, and lung homogenates were collected 24 h later for plaque assay analysis. Data presented correspond to mean ± SD. ∗ p < 0.05, ∗∗∗ p < 0.001. Statistical analysis was performed using one-way ANOVA followed by Tukey’s post hoc test. (G) Prophylactic treatment. SARS-CoV-2 was administered intranasally 30 min after intranasal administration of CGM23 or EK1C4 (12.5 μg, 0.865 mg/kg; 25 μg, 1.73 mg/kg). Lung tissues were collected 24 h later for plaque assay analysis.

Article Snippet: Live virus experiments were performed with Calu-6 epithelial cells (ATCC HTB-56) stably expressing human Angiotensin Converting Enzyme 2 (ACE2) (OriGene, RC08442) as target cells.

Techniques: In Vivo, Drug discovery, Virus, Infection, Luciferase, Staining, Plaque Assay