Journal: mBio

Article Title: Re-infection with SARS-CoV-2 is associated with increased antibody breadth and potency against diverse sarbecovirus strains

doi: 10.1128/mbio.03612-25

Figure Lengend Snippet: Functional activity of PVI-2 antibodies compared to PVI-1 antibodies from the same clonal family. ( A ) Percent somatic hypermutation of IgG heavy chain and light chain among clonal lineage members. ( B ) Comparison of binding profiles between PVI-1 mAbs and clonal lineage members in PVI-2. The heatmap shows OD450 nm binding activity by ELISA, with the antigens tested shown to the left. The antibodies tested are indicated at the top with mAbs from PVI-1 in orange text and PVI-2 in black text. mAbs were tested in duplicate at a fixed concentration of 1,000 ng/mL. Green indicates binding with increasing shades of green indicating increasing OD450 values, as indicated in the key to the right. The cases with the darkest green (>3.0 OD450) are qualitative and not quantitative results, as the assay would be saturated for the most potent binding mAbs. Gray indicates no detectable binding. ( C ) Heatmap of neutralization IC50s (µg/mL) of the same antibodies as in panel B. Viruses tested are shown to the left, with SARS-CoV-2 variants in the top half and more diverse sarbecoviruses in the bottom half. The color gradient represents neutralization activity as shown in the key to the right, with darker shades of blue correlating with IC50 potency. Gray indicates no detectable neutralization (IC50), and white indicates the mAbs were not tested because they did not bind SARS-CoV-1 spike trimer. IC50 values were averaged from 2 to 6 independent experiments performed in technical duplicate. IC50 values were calculated with GraphPad Prism, with a four-parameter non-linear regression model. ( D ) Geometric mean of the IC50 values (µg/mL) and 95% confidence intervals (CI) of the panel of viruses tested in panel C . IC50 >20 µg/mL was set to 20 µg/mL in this calculation. The number of viruses neutralized is displayed as a fraction of viruses that the antibody neutralizes with an IC50 <20 µg/mL, over the total number of viruses the antibody was tested against.

Article Snippet: All described antibodies were tested for binding to SARS-CoV-2 WH-1 RBD (Sino Biological, cat. 40592-V08H), SARS-CoV-2 WH-1 S1 (Sino Biological, cat. 40591-V08H), SARS-CoV-2 XBB.1.5 trimer (40589-V08H45), and SARS-CoV-1 GD01 trimer (Acro Biosystems, cat. SPN-S52Ht).

Techniques: Functional Assay, Activity Assay, Comparison, Binding Assay, Enzyme-linked Immunosorbent Assay, Concentration Assay, Neutralization

Journal: mBio

Article Title: Re-infection with SARS-CoV-2 is associated with increased antibody breadth and potency against diverse sarbecovirus strains

doi: 10.1128/mbio.03612-25

Figure Lengend Snippet: Binding and neutralization of antibodies representing new clonal lineages specific to PVI-2. ( A ) Heatmap shows binding (green) and neutralization IC50s (blue, last two columns). Viruses tested are shown at the top, and mAbs are indicated to the left, after the clonal family designation. IC50 values were averaged from two independent experiments performed in technical duplicate. Figure details are as described in . ( B ) Comparison of IC50s for SARS-CoV-2 XBB1.5 and SARS-CoV-1 for antibodies from PVI-2 specific clonal lineages. The P value is calculated from the Wilcoxon matched-paired signed rank test. Antibodies with no neutralization activity (IC50 > 20 µg/mL) were set to 20 µg/mL for this comparison.

Article Snippet: All described antibodies were tested for binding to SARS-CoV-2 WH-1 RBD (Sino Biological, cat. 40592-V08H), SARS-CoV-2 WH-1 S1 (Sino Biological, cat. 40591-V08H), SARS-CoV-2 XBB.1.5 trimer (40589-V08H45), and SARS-CoV-1 GD01 trimer (Acro Biosystems, cat. SPN-S52Ht).

Techniques: Binding Assay, Neutralization, Comparison, Activity Assay

Journal: mBio

Article Title: Re-infection with SARS-CoV-2 is associated with increased antibody breadth and potency against diverse sarbecovirus strains

doi: 10.1128/mbio.03612-25

Figure Lengend Snippet: Functional characterization of a pan-sarbecovirus neutralizing antibody C68.490. ( A ) Binding breadth of C68.490 and previously characterized antibodies with known pan-sarbecovirus activity against a library of yeast-display sarbecovirus RBDs. Antibodies tested are shown to the left with the specific RBD indicated at the bottom. RBDs are classified by clades as shown above and color-coded. Data for VIR-7229, SA55, and S2X259 were previously published by reference and shown for comparison. ( B ) Comparison of C68.490 binding with other pan-sarbecovirus antibodies by sarbecovirus clade. Statistically significant differences in mean EC50 values between C68.490 and other antibodies were assessed using the Friedman test with Dunn’s multiple comparisons test. Sarbecovirus RBDs were assigned to clades based on existing clade definitions . ( C ) Neutralization of SARS-CoV-2 and sarbecovirus variants by C68.490. Antibodies tested are described at the top and include two control mAbs for comparison. The viruses tested are shown to the left, with a line separating SARS-CoV-2 variants from the more diverse sarbecoviruses. Neutralization data are represented as IC50s (µg/mL) and color-coded as shown in the table below. IC50 values were averaged from 2 to 4 independent experiments performed in technical duplicate, with the exception of neutralization of S2X259 against SARS-CoV-1, which was only tested once. Data for C68.61, which was tested in parallel to the C68.490, was also reported in reference . Other details are as in .

Article Snippet: All described antibodies were tested for binding to SARS-CoV-2 WH-1 RBD (Sino Biological, cat. 40592-V08H), SARS-CoV-2 WH-1 S1 (Sino Biological, cat. 40591-V08H), SARS-CoV-2 XBB.1.5 trimer (40589-V08H45), and SARS-CoV-1 GD01 trimer (Acro Biosystems, cat. SPN-S52Ht).

Techniques: Functional Assay, Binding Assay, Activity Assay, Comparison, Neutralization, Control

Journal: mBio

Article Title: Re-infection with SARS-CoV-2 is associated with increased antibody breadth and potency against diverse sarbecovirus strains

doi: 10.1128/mbio.03612-25

Figure Lengend Snippet: Characterization of C68.490 escape mutations. ( A ) Top, sites of binding escape and residues conferring escape from C68.490 in different viral backgrounds (WH1 = SARS-CoV-2 Wuhan-Hu-1, BA.2 = SARS-CoV-2 Omicron BA.2, SARS1 = SARS-CoV-1 Urbani) by deep mutational scanning of the RBD. Amino acid numbering based on the SARS-CoV-2 WH1 sequence. Bottom, sites of escape mapped onto surface representation of the RBD (key interacting motifs of ACE2 shown as the gray ribbon). Color gradient represents the escape fraction, with darker red encompassing degree of escape. ( B ) Multi-clade sarbecovirus sequence alignments. Conserved sites (in blue) and variable residues (in white) across sarbecoviruses around the epitope of C68.490 defined in panel A are depicted. C68.490 sites of escape are indicated with yellow arrows. ( C ) Genotype at SARS-CoV-2 spike amino acid sites 378 and 384 from 2,967 GenBank sequences. Adapted from Nextstrain.org (retrieved 16 November 2025).

Article Snippet: All described antibodies were tested for binding to SARS-CoV-2 WH-1 RBD (Sino Biological, cat. 40592-V08H), SARS-CoV-2 WH-1 S1 (Sino Biological, cat. 40591-V08H), SARS-CoV-2 XBB.1.5 trimer (40589-V08H45), and SARS-CoV-1 GD01 trimer (Acro Biosystems, cat. SPN-S52Ht).

Techniques: Binding Assay, Sequencing

Journal: Signal Transduction and Targeted Therapy

Article Title: Inducible CD147 up-regulation boosts extended SARS-CoV-2 infection triggering severe COVID-19 independent of ACE2

doi: 10.1038/s41392-025-02551-x

Figure Lengend Snippet: Cryo-EM structure demonstrates CD147-spike interaction. a Cryo-EM map of the CD147-spike complex. The RBD up protomer, green; the two RBD down protomers, sandy brown and blue; CD147, magenta. b The overall structure of the CD147-spike complex shown as cartoons in side (left) and top (right) views. c The overlaid structures of CD147-spike and spike-closed are shown in surface representation. CD147 is depicted in magenta, with the spike protomer in the up and down conformations shown in green and cyan, respectively. The contact patch recognized by CD147 is highlighted in yellow on the down RBD. d The structure and key residues within the binding interface of the CD147-spike complex. The key residues forming hydrogen bonds are presented by stick models, with the hydrogen-bonding interactions labeled in yellow lines. e The binding ability of spike RBD with wildtype CD147 or its mutants (CD147-R54A, E84A, E92A, Q100A, and S112A) and CD147 with wildtype spike RBD or its mutants (G413A, K417A, K424A, G447A, and Y489A) was determined by SPR assay. f The binding ability of CD147 with wildtype spike RBD or its mutants (spike RBD-Beta, Gamma, and JN.1) was determined by SPR assay. g The virus loads and relative luciferase signals in CD147/ACE2 double knockout Vero E6 cells transfected with either wild type CD147 or mutated CD147 were determined by Taqman-based RT-PCR and dual-luciferase reporter assays, respectively, *** p < 0.001. h The overlaid structures of the CD147-spike complex, colored as in (a), and the CD147-Meplazumab Fab complex (PDB ID: 5X0T), colored in gray. The up RBD and Meplazumab Fab are depicted as surfaces, with the binding epitopes on CD147 (residues 61-75, colored in red) recognized by Meplazumab. The steric hindrance between Meplazumab and the spike bound to CD147 is indicated with orange arrows. i The competitive inhibitory role of MPZ for the binding of CD147 and SARS-CoV-2 spike (RBD) protein was determined by ELISA assay

Article Snippet: The mobile phases contained the mutants of CD147 (His-CD147-R54A, His-CD147-E84A, His-CD147-E92A, His-CD147-Q100A, His-CD147-S112A, our laboratory), the mutants of RBD (His-RBD-G413A, His-RBD-K417A, His-RBD-K424A, His-RBD-G447A, His-RBD-Y489A, Sino Biological), His-RBD (WT) (40592-V08H, Sino Biological), His-RBD (Beta) (40592-V08H85, Sino Biological), His-RBD (Gamma) (40592-V08H86, Sino Biological), His-RBD (JN.1) (40592-V08H155, Sino Biological), rhesus macaque CD147 (Sino Biological), human ACE2 (Sino Biological), and rhesus macaque ACE2 (Sino Biological).

Techniques: Cryo-EM Sample Prep, Binding Assay, Labeling, SPR Assay, Virus, Luciferase, Double Knockout, Transfection, Reverse Transcription Polymerase Chain Reaction, Enzyme-linked Immunosorbent Assay

Journal: npj Viruses

Article Title: K5 polysaccharides inhibit SARS-CoV-2 infection by preventing spike-proteolytic priming

doi: 10.1038/s44298-025-00163-4

Figure Lengend Snippet: a Representative images of syncytia formation assay in VeroE6 cells upon treatment (350 µM) with K5 compounds. Scale bar: 50 µm. b Number of nuclei involved in syncytia formation is higher in Wuhan-Hu-1 spike-positive cells than in Omicron BA.1 spike-positive cells. c Effect of K5 compounds on syncytia formation induced by Wuhan-Hu-1 spike. d Effect of K5 compounds on syncytia formation induced by Omicron BA.1 spike. Only spike-positive cells were quantified. Data of four (Wuhan-Hu-1) and three (Omicron BA.1) independent experiments. Values are mean ± sd. P values determined by Welch’s t-test: * P < 0.05; ** P < 0.005.

Article Snippet: Reagents and materials were used as received, unless otherwise mentioned, and were purchased from the following: Human recombinant SARS-CoV-2 Wuhan-Hu-1 spike His-Tag protein and RBD from Sino Biological (#40592-V08B); ACE2 from Acrobiosystem (#AC2-H52H8); Bovine Serum Albumin (BSA) from Merck (#810037); Human recombinant furin from OriGene Technologies Inc. (#TP304279M); Conventional heparin (13.6 kDa - purity ≥95%) from a commercial batch of unfractionated sodium heparin from Laboratori Derivati Organici S.p.A. (#9041-08-1).

Techniques: Tube Formation Assay

Journal: npj Viruses

Article Title: K5 polysaccharides inhibit SARS-CoV-2 infection by preventing spike-proteolytic priming

doi: 10.1038/s44298-025-00163-4

Figure Lengend Snippet: VeroE6 cells or A549 ACE2+ cells were treated with increasing concentrations of heparin, K5, K5OSH, and K5NOSH. a , b The cells remained viable in the presence of heparin and the K5 compounds as evaluated by measuring the ATP levels. VeroE6 or A549 ACE2+ cells were infected with the B.1 c , d or Omicron BA.1 e , f isolates in the presence or the absence of increasing concentrations of heparin, K5, K5OSH, and K5NOSH. Infection was reduced in a concentration-dependent manner as shown by the percentage of plaque reduction compared to SARS-CoV-2 alone. Data are presented as the mean value ± standard error of three independent replicates. * P < 0.05; ** P < 0.005.

Article Snippet: Reagents and materials were used as received, unless otherwise mentioned, and were purchased from the following: Human recombinant SARS-CoV-2 Wuhan-Hu-1 spike His-Tag protein and RBD from Sino Biological (#40592-V08B); ACE2 from Acrobiosystem (#AC2-H52H8); Bovine Serum Albumin (BSA) from Merck (#810037); Human recombinant furin from OriGene Technologies Inc. (#TP304279M); Conventional heparin (13.6 kDa - purity ≥95%) from a commercial batch of unfractionated sodium heparin from Laboratori Derivati Organici S.p.A. (#9041-08-1).

Techniques: Infection, Concentration Assay

Journal: Frontiers in Immunology

Article Title: Dual role of ACE2 in regulating inflammation triggered by Omicron S1 and other SARS-CoV-2 Spike variants

doi: 10.3389/fimmu.2025.1667880

Figure Lengend Snippet: Omicron S1 shows reduced immune cells recruitment and expansion compared with the ancestral variant. Recombinant S1WT, S1 Omicron or vehicle (-) were injected in the hindbrain ventricle (HBV) of Tg(lyz:DsRED) (A) , Tg(mfap4:Tomato) (B) , Tg(nfkb:eGFP) (C) of 2-dpf larvae. Neutrophil (A) and macrophage (B) recruitment and number and Nfkb reporter activity (C) were analyzed at 6, 12, and/or 24 hpi by fluorescence microscopy. Representative photos for each treatment are shown from 24 hpi. Scale bar 500 μm. Each dot represents one individual, and the means ± SEM for each group is also shown. P values were calculated using one-way analysis of variance (ANOVA) and Tukey multiple range test. ns, not significant; * P ≤ 0.05, ** P ≤ 0.01, *** P ≤ 0.001 and **** p < 0.0001. auf, arbitrary units of fluorescence.

Article Snippet: Recombinant His-tagged Spike S1 wild-type (#40591-V08B1), S1 Omicron (#40592-V08H121) or Spike S1/S2 TRIMER wild-type (#40589-V08H8), all from Sino Biological at a concentration of 0.25 mg/ml supplemented with phenol red were injected into the hindbrain (1 nl) of 48 hpf zebrafish larvae.

Techniques: Variant Assay, Recombinant, Injection, Activity Assay, Fluorescence, Microscopy

Journal: Frontiers in Immunology

Article Title: Dual role of ACE2 in regulating inflammation triggered by Omicron S1 and other SARS-CoV-2 Spike variants

doi: 10.3389/fimmu.2025.1667880

Figure Lengend Snippet: Omicron is more proinflammatory than the ancestral variant. Recombinant S1WT, S1 Omicron or vehicle (-) were injected in the hindbrain ventricle (HBV) of WT (A–F) 2-dpf larvae. The transcript levels of the indicated genes (A–E) were analyzed at 12 hpi by RT-qPCR in larval head and rest of the body and caspase-1 activity was determined at 24 hpi using a fluorogenic substrate (F) . Graphs shown are representative of three independent experiments; technical replicates are displayed in each graph. The means ± SEM for each group is shown. P values were calculated using one-way analysis of variance (ANOVA) and Tukey multiple range test. n=45 in (A–E) , n=35 in (F) . ns, not significant; * P ≤ 0.05, ** P ≤ 0.01, *** P ≤ 0.001 and **** p < 0.0001. auf, arbitrary units of fluorescence.

Article Snippet: Recombinant His-tagged Spike S1 wild-type (#40591-V08B1), S1 Omicron (#40592-V08H121) or Spike S1/S2 TRIMER wild-type (#40589-V08H8), all from Sino Biological at a concentration of 0.25 mg/ml supplemented with phenol red were injected into the hindbrain (1 nl) of 48 hpf zebrafish larvae.

Techniques: Variant Assay, Recombinant, Injection, Quantitative RT-PCR, Activity Assay, Fluorescence

Journal: Frontiers in Immunology

Article Title: Dual role of ACE2 in regulating inflammation triggered by Omicron S1 and other SARS-CoV-2 Spike variants

doi: 10.3389/fimmu.2025.1667880

Figure Lengend Snippet: Omicron causes higher neutrophil cell death than the ancestral variant. Recombinant S1WT, S1 Omicron or vehicle (-) were injected in the hindbrain ventricle (HBV) of Tg(lyz:DsRED) (A, B) of 2-dpf larvae. Tunel positive neutrophil number (double positive) was counted at 6 hpi in the head and tail of the larvae (A, B) . Representative photos for each treatment are shown. Scale bar 500 μm. Each dot represents one individual, and the means ± SEM for each group is also shown. P values were calculated using one-way analysis of variance (ANOVA) and Tukey multiple range test. ns, not significant; * P ≤ 0.05, ** P ≤ 0.01 and **** p < 0.0001.

Article Snippet: Recombinant His-tagged Spike S1 wild-type (#40591-V08B1), S1 Omicron (#40592-V08H121) or Spike S1/S2 TRIMER wild-type (#40589-V08H8), all from Sino Biological at a concentration of 0.25 mg/ml supplemented with phenol red were injected into the hindbrain (1 nl) of 48 hpf zebrafish larvae.

Techniques: Variant Assay, Recombinant, Injection, TUNEL Assay

Journal: Frontiers in Immunology

Article Title: Dual role of ACE2 in regulating inflammation triggered by Omicron S1 and other SARS-CoV-2 Spike variants

doi: 10.3389/fimmu.2025.1667880

Figure Lengend Snippet: Trimeric ancestral variant induces a weaker immune response than its monomeric form. Recombinant S1WT (monomeric), S1/S2WT-T (trimeric) or vehicle (-) were injected in the hindbrain ventricle (HBV) of Tg(lyz:DsRED) (A) , Tg(mfap4:Tomato) (B) , Tg( nfkb :eGFP) (C) 2-day postfertilization larvae (dpf). Neutrophil (A) and macrophage (B) recruitment and number and Nfkb reporter activity (C) were analyzed at 6, 12, and/or 24 hpi by fluorescence microscopy. Representative photos for each treatment are shown from 24 hpi. Scale bar 500 μm. Each dot represents one individual, and the means ± SEM for each group is also shown. P values were calculated using one-way analysis of variance (ANOVA) and Tukey multiple range test. ns, not significant; * P ≤ 0.05, ** P ≤ 0.01, *** P ≤ 0.001 and **** p < 0.0001. auf, arbitrary units of fluorescence.

Article Snippet: Recombinant His-tagged Spike S1 wild-type (#40591-V08B1), S1 Omicron (#40592-V08H121) or Spike S1/S2 TRIMER wild-type (#40589-V08H8), all from Sino Biological at a concentration of 0.25 mg/ml supplemented with phenol red were injected into the hindbrain (1 nl) of 48 hpf zebrafish larvae.

Techniques: Variant Assay, Recombinant, Injection, Activity Assay, Fluorescence, Microscopy

Journal: Frontiers in Immunology

Article Title: Dual role of ACE2 in regulating inflammation triggered by Omicron S1 and other SARS-CoV-2 Spike variants

doi: 10.3389/fimmu.2025.1667880

Figure Lengend Snippet: Trimeric ancestral variant induces a weaker proinflammatory response than its monomeric form. Recombinant S1WT, S1/S2WT-T or vehicle (-) were injected in the hindbrain ventricle (HBV) of WT (A–E) 2-day postfertilization larvae (dpf). The transcript levels of the indicated genes (A–D) were analyzed at 12 hpi by RT-qPCR in larval head and rest of the body and caspase-1 activity was determined at 24 hpi using a fluorogenic substrate (E) . Graphs shown are representative of three independent experiments; technical replicates are displayed in each graph. The means ± SEM for each group is shown. P values were calculated using one-way analysis of variance (ANOVA) and Tukey multiple range test. n=40 in A-D, n=35 in E. ns, not significant; * P ≤ 0.05, ** P ≤ 0.01, *** P ≤ 0.001 and **** p < 0.0001. auf, arbitrary units of fluorescence.

Article Snippet: Recombinant His-tagged Spike S1 wild-type (#40591-V08B1), S1 Omicron (#40592-V08H121) or Spike S1/S2 TRIMER wild-type (#40589-V08H8), all from Sino Biological at a concentration of 0.25 mg/ml supplemented with phenol red were injected into the hindbrain (1 nl) of 48 hpf zebrafish larvae.

Techniques: Variant Assay, Recombinant, Injection, Quantitative RT-PCR, Activity Assay, Fluorescence