omicron spike  (Native Antigen Inc)

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: bioRxiv

Article Title: Polymer-lipid hybrid nanoparticle enhances mRNA delivery and T cell-mediated immunity

doi: 10.64898/2026.01.22.701138

Figure Lengend Snippet: (a) Schematic illustration of the design of LNP and PLNP. (b) Left: sizes of LNP and PLNP measured by dynamic light scattering (DLS). Right: TEM images of LNP and PLNP. Scale bars: 100 nm. (c) Polydispersity index (PDI) of LNP and PLNP. (d) mRNA encapsulation efficiencies of LNP and PLNP. (e) Spike mRNA translation in RAW 264.7 macrophages after incubation with spike mRNA-loaded LNP or PLNP for 48 hours. Spike expression were measured by flow cytometry. Dose: 1 µg mRNA/mL. n = 3. (f) FLuc mRNA translation in RAW 264.7 macrophages on day 1, 2, 3, and 5 after incubation with FLuc mRNA-loaded LNP or PLNP. Dose: 1 µg mRNA/mL. n = 3. The FLuc signals were normalized to the day-1 signal of LNP-treated group. (g) Left: Representative flow plots of CD11c + DCs expressing SIINFEKL/H-2K b after incubation with OVA mRNA-loaded LNP or PLNP for 48 hours. Right: The percentages of CD11c + SIINFEKL/H-2K b+ DCs in total DCs. Dose: 1 µg mRNA/mL. n = 3. (h) Intracellular cytokine levels in RAW 264.7 macrophages after incubation with spike mRNA-loaded LNP, spike mRNA-loaded PLNP, empty LNP, or empty PLNP for 24 hours. Left: IFN-γ. Middle: TNF-α. Right: IL-2. Dose: 1 µg mRNA/mL. n = 3. (i) Cytokine secretion from human PBMCs after incubation with spike mRNA-loaded LNP, spike mRNA-loaded PLNP, empty LNP, or empty PLNP for 24 hours. Dose: 1 µg mRNA/mL. n = 3. (j) Schematic illustration of PLNP enhancing antigen presentation and proinflammatory cytokine generation in APCs. Data are presented as mean ± s.e.m. Statistical significance was determined using two-sided unpaired t-test (d, e, g), one-way ANOVA with Tukey post hoc test for multiple comparisons (h), or two-way ANOVA with Tukey post hoc test for multiple comparisons ns: no significance, * P < 0.05, ** P < 0.01, *** P < 0.001, and ****P < 0.0001.

Article Snippet: Wild-type SARS-CoV-2 spike encoding plasmid was obtained from the MacMaster lab. Omicron spike (B.1.1.529), influenza A H1N1 (A/Puerto Rico/8/1934) hemagglutinin (HA), and FLuc sequences were obtained from commercially available omicron spike, HA, and FLuc Gene ORF cDNA clone expression plasmids (Sino Biological #VG40835-UT, Sino Biological #VG11684-UT, and Addgene #101156) and inserted into the same plasmid backbone using Gibson assembly.

Techniques: Encapsulation, Incubation, Expressing, Flow Cytometry, Immunopeptidomics

Journal: bioRxiv

Article Title: Polymer-lipid hybrid nanoparticle enhances mRNA delivery and T cell-mediated immunity

doi: 10.64898/2026.01.22.701138

Figure Lengend Snippet: (a) Left: In vivo luminescence images of BALB/c mice treated with 1×PBS, FLuc mRNA-loaded LNP, or FLuc mRNA-loaded PLNP at 4, 24, 48, 72, and 96 hours post administration. Right: In vivo luminescence signals measured by integration of total flux for each mouse. Dose: 5 µg mRNA/mouse. N = 5. (b) Left: Fluorescence images of lymph nodes collected from C57BL/6 mice at 24 h post vaccination with DiD-labeled spike mRNA-loaded LNP or PLNP. Right: Quantification of LNP and PLNP accumulation in lymph nodes at 24 h post vaccination. Dose: 10 µg mRNA/mouse. n = 4. (c) Innate immune cell activation (CD86 + ) at 7 days post boost vaccination. C57BL/6 mice were vaccinated with spike mRNA-loaded LNP or PLNP on day 0 and boosted with same doses on day 21. Dose: 10 µg mRNA/mouse. n = 5. Left: DCs. Middle: Macrophages. Right: Monocytes. (d) Schematic illustration of PLNP enhancing lymph node targeting and innate immune cell activation. Data are presented as mean ± s.e.m. Statistical significance was determined using two-way ANOVA with Tukey post hoc test for multiple comparisons (a) or one-way ANOVA with Tukey post hoc test for multiple comparisons (b, c). ns: no significance, * P < 0.05, ** P < 0.01, *** P < 0.001, and ****P < 0.0001.

Article Snippet: Wild-type SARS-CoV-2 spike encoding plasmid was obtained from the MacMaster lab. Omicron spike (B.1.1.529), influenza A H1N1 (A/Puerto Rico/8/1934) hemagglutinin (HA), and FLuc sequences were obtained from commercially available omicron spike, HA, and FLuc Gene ORF cDNA clone expression plasmids (Sino Biological #VG40835-UT, Sino Biological #VG11684-UT, and Addgene #101156) and inserted into the same plasmid backbone using Gibson assembly.

Techniques: In Vivo, Fluorescence, Labeling, Activation 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