anti s2  (Sino Biological)


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  • 99
    Name:
    SARS CoV 2 2019 nCoV Spike S1 Antibody Rabbit MAb
    Description:
    This product is a recombinant monoclonal antibody expressed from HEK293 cells
    Catalog Number:
    40150-R007
    Price:
    None
    Category:
    Primary Antibody
    Reactivity:
    2019 nCoV
    Applications:
    ELISA
    Product Aliases:
    Anti-coronavirus spike Antibody, Anti-cov spike Antibody, Anti-ncov RBD Antibody, Anti-ncov s1 Antibody, Anti-ncov s2 Antibody, Anti-ncov spike Antibody, Anti-NCP-CoV RBD Antibody, Anti-NCP-CoV s1 Antibody, Anti-NCP-CoV s2 Antibody, Anti-NCP-CoV Spike Antibody, Anti-novel coronavirus RBD Antibody, Anti-novel coronavirus s1 Antibody, Anti-novel coronavirus s2 Antibody, Anti-novel coronavirus spike Antibody, Anti-RBD Antibody, Anti-S1 Antibody, Anti-S2 Antibody, Anti-Spike RBD Antibody
    Antibody Type:
    MAb
    Host:
    Rabbit
    Isotype:
    Rabbit IgG
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    Structured Review

    Sino Biological anti s2
    N-glycan modification of SARS-CoV-2 pseudovirus abolishes entry into 293T/ACE2 cells. A . Pseudovirus expressing VSVG envelope protein, Spike-WT and Spike-mutant were produced in wild-type, [O] − and [N] − 293T cells. All 9 viruses were applied at equal titer to stable 293T/ACE2. B - C . O-glycan truncation of Spike partially reduced viral entry. N-glycan truncation abolished viral entry. In order to combine data from multiple viral preparations and independent runs in a single plot, all data were normalized by setting DsRed signal produced by virus generated in wild-type 293T to 10,000 normalized MFI or 100% normalized DsRed positive value. D . Viral titration study performed with Spike-mutant virus shows complete loss of viral infection over a wide range. E . Western blot of Spike protein using <t>anti-S2</t> Ab shows reduced proteolysis of Spike-mut compared to Spike-WT. The full Spike protein and free S2-subunit resulting from S1-S2 cleavage is indicated. Molecular mass is reduced in [N] − 293T products due to truncation of glycan biosynthesis. F . Anti-FLAG Ab binds the C-terminus of Spike-mutant. Spike produced in [N] − 293Ts is almost fully proteolyzed during viral production (red arrowhead). * P
    This product is a recombinant monoclonal antibody expressed from HEK293 cells
    https://www.bioz.com/result/anti s2/product/Sino Biological
    Average 99 stars, based on 1 article reviews
    Price from $9.99 to $1999.99
    anti s2 - by Bioz Stars, 2021-07
    99/100 stars

    Images

    1) Product Images from "Inhibition of SARS-CoV-2 viral entry in vitro upon blocking N- and O-glycan elaboration"

    Article Title: Inhibition of SARS-CoV-2 viral entry in vitro upon blocking N- and O-glycan elaboration

    Journal: bioRxiv

    doi: 10.1101/2020.10.15.339838

    N-glycan modification of SARS-CoV-2 pseudovirus abolishes entry into 293T/ACE2 cells. A . Pseudovirus expressing VSVG envelope protein, Spike-WT and Spike-mutant were produced in wild-type, [O] − and [N] − 293T cells. All 9 viruses were applied at equal titer to stable 293T/ACE2. B - C . O-glycan truncation of Spike partially reduced viral entry. N-glycan truncation abolished viral entry. In order to combine data from multiple viral preparations and independent runs in a single plot, all data were normalized by setting DsRed signal produced by virus generated in wild-type 293T to 10,000 normalized MFI or 100% normalized DsRed positive value. D . Viral titration study performed with Spike-mutant virus shows complete loss of viral infection over a wide range. E . Western blot of Spike protein using anti-S2 Ab shows reduced proteolysis of Spike-mut compared to Spike-WT. The full Spike protein and free S2-subunit resulting from S1-S2 cleavage is indicated. Molecular mass is reduced in [N] − 293T products due to truncation of glycan biosynthesis. F . Anti-FLAG Ab binds the C-terminus of Spike-mutant. Spike produced in [N] − 293Ts is almost fully proteolyzed during viral production (red arrowhead). * P
    Figure Legend Snippet: N-glycan modification of SARS-CoV-2 pseudovirus abolishes entry into 293T/ACE2 cells. A . Pseudovirus expressing VSVG envelope protein, Spike-WT and Spike-mutant were produced in wild-type, [O] − and [N] − 293T cells. All 9 viruses were applied at equal titer to stable 293T/ACE2. B - C . O-glycan truncation of Spike partially reduced viral entry. N-glycan truncation abolished viral entry. In order to combine data from multiple viral preparations and independent runs in a single plot, all data were normalized by setting DsRed signal produced by virus generated in wild-type 293T to 10,000 normalized MFI or 100% normalized DsRed positive value. D . Viral titration study performed with Spike-mutant virus shows complete loss of viral infection over a wide range. E . Western blot of Spike protein using anti-S2 Ab shows reduced proteolysis of Spike-mut compared to Spike-WT. The full Spike protein and free S2-subunit resulting from S1-S2 cleavage is indicated. Molecular mass is reduced in [N] − 293T products due to truncation of glycan biosynthesis. F . Anti-FLAG Ab binds the C-terminus of Spike-mutant. Spike produced in [N] − 293Ts is almost fully proteolyzed during viral production (red arrowhead). * P

    Techniques Used: Modification, Expressing, Mutagenesis, Produced, Generated, Titration, Infection, Western Blot

    Related Articles

    other:

    Article Title: Rapid and quantitative detection of SARS-CoV-2 specific IgG for convalescent serum evaluation
    Article Snippet: D001, D003, and D006 have similar affinity towards SARS-CoV-2 S1 and much better than CR3022.

    Article Title: Membrane Nanoparticles Derived from ACE2-rich Cells Block SARS-CoV-2 Infection
    Article Snippet: To determine the content of SARS-CoV-2 S1 adhered to HK-2, cells were seeded into a 6-well plate at a density of 1 × 106 cells/well.

    Enzyme-linked Immunosorbent Assay:

    Article Title: Immune responses to SARS-CoV-2 in three children of parents with symptomatic COVID-19
    Article Snippet: .. Plasma S1 and RBD ELISA The ELISA method used to measure IgG, IgM, and IgA levels to SARS-COV-2 S1 and RBD protein was based on Amanat et al. . .. Briefly, 96-well high-binding plates (Thermo Fisher Scientific) were coated with S1 or RBD (Sino Biological) diluted in PBS at 2 µg/mL and then incubated at 4 °C overnight.

    Western Blot:

    Article Title: Inhibition of SARS-CoV-2 viral entry in vitro upon blocking N- and O-glycan elaboration
    Article Snippet: Final protein concentration was determined in ELISA format by using a calibrant Fc-protein of known concentration that was verified to be > 95% pure based on silver stain analysis. .. Identity of expressed protein and also viral Spike was determined using western blotting with anti-Fc (Jackson), anti-RBD (Sino Biologicals), anti-S2 (Sino Biologicals) and anti-ACE2 (R & D Systems) pAbs. .. Identity of expressed protein and also viral Spike was determined using western blotting with anti-Fc (Jackson), anti-RBD (Sino Biologicals), anti-S2 (Sino Biologicals) and anti-ACE2 (R & D Systems) pAbs.

    Expressing:

    Article Title: SARS‑CoV-2 RBD219-N1C1: A yeast-expressed SARS-CoV-2 recombinant receptor-binding domain candidate vaccine stimulates virus neutralizing antibodies and T-cell immunity in mice
    Article Snippet: Transformants were selected on YPD plates containing different concentrations of Zeocin (100–2000 μg/mL) and incubated at 30°C for 72 hours. .. Individual colonies were screened for expression under induction with methanol (0.5–2%) at the 10 mL culture level (BMMY medium) as described., The expression level of select colonies was identified by SDS-PAGE and immunoblotting using anti-SARS-CoV-2 antibodies (anti-SARS-CoV-2 spike rabbit monoclonal antibody, Sino Biological, Cat # 40150-R007), and research seed stocks of the highest expressing clones were frozen at – 80°C. .. RBD219-WT and RBD219-N1C1 were expressed at the 5 L scale using a Celligen 310 benchtop fermentation system (Eppendorf).

    SDS Page:

    Article Title: SARS‑CoV-2 RBD219-N1C1: A yeast-expressed SARS-CoV-2 recombinant receptor-binding domain candidate vaccine stimulates virus neutralizing antibodies and T-cell immunity in mice
    Article Snippet: Transformants were selected on YPD plates containing different concentrations of Zeocin (100–2000 μg/mL) and incubated at 30°C for 72 hours. .. Individual colonies were screened for expression under induction with methanol (0.5–2%) at the 10 mL culture level (BMMY medium) as described., The expression level of select colonies was identified by SDS-PAGE and immunoblotting using anti-SARS-CoV-2 antibodies (anti-SARS-CoV-2 spike rabbit monoclonal antibody, Sino Biological, Cat # 40150-R007), and research seed stocks of the highest expressing clones were frozen at – 80°C. .. RBD219-WT and RBD219-N1C1 were expressed at the 5 L scale using a Celligen 310 benchtop fermentation system (Eppendorf).

    Clone Assay:

    Article Title: SARS‑CoV-2 RBD219-N1C1: A yeast-expressed SARS-CoV-2 recombinant receptor-binding domain candidate vaccine stimulates virus neutralizing antibodies and T-cell immunity in mice
    Article Snippet: Transformants were selected on YPD plates containing different concentrations of Zeocin (100–2000 μg/mL) and incubated at 30°C for 72 hours. .. Individual colonies were screened for expression under induction with methanol (0.5–2%) at the 10 mL culture level (BMMY medium) as described., The expression level of select colonies was identified by SDS-PAGE and immunoblotting using anti-SARS-CoV-2 antibodies (anti-SARS-CoV-2 spike rabbit monoclonal antibody, Sino Biological, Cat # 40150-R007), and research seed stocks of the highest expressing clones were frozen at – 80°C. .. RBD219-WT and RBD219-N1C1 were expressed at the 5 L scale using a Celligen 310 benchtop fermentation system (Eppendorf).

    Incubation:

    Article Title: Inhibition of HECT E3 ligases as potential therapy for COVID-19
    Article Snippet: .. After a ~1.5 day incubation, cells were treated with 10% buffered formalin for at least 6 h, washed in PBS and virus antigen stained with SARS-CoV-2 specific antibody (Sino Biologicals, MM05) together with Hoechst 33342 dye to stain cell nuclei. .. Plates were imaged by a Biotek Cytation 1 microscope and automated image analysis was used to count total number of infected cells and total cell nuclei.

    Staining:

    Article Title: Inhibition of HECT E3 ligases as potential therapy for COVID-19
    Article Snippet: .. After a ~1.5 day incubation, cells were treated with 10% buffered formalin for at least 6 h, washed in PBS and virus antigen stained with SARS-CoV-2 specific antibody (Sino Biologicals, MM05) together with Hoechst 33342 dye to stain cell nuclei. .. Plates were imaged by a Biotek Cytation 1 microscope and automated image analysis was used to count total number of infected cells and total cell nuclei.

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  • 86
    sino biological sars cov 2 strains
    Impact of Spike G614 variant on the seropositivity of <t>SARS-CoV-2</t> infected patients. (A-B) Protein structure of Spike obtained from the Protein Data Bank (PDB ID6zb5 for D614 variant and PDB ID6xs6 for G614 variant). (A) The region in which the amino acid 614 was localized (square) on the trimer of Spike molecules (in green, orange and yellow) was further analyzed in D. (B) Predicted residue interactions with electrostatic (middle panels) and lipophibic (right panels) properties were compared between Spike D614 and G614 variants. (C) Sera from COVID-19 patients developing mild (blue, n=17), moderate (green, n=13) and severe (orange, n=15) forms of COVID-19 were re-evaluated in the SARS-CoV-2 serological assay using Spike D614 and G614 expressing HEK cells. Specific binding of IgG (circles), IgM (squares) and IgA (diamonds) were represented and thresholds (grey boxes) were obtained with the basal levels of Ig binding from control sera tested in Figure 2A . (D) Percentage of patients with decreased seropositivity against D614 and G614 variants from the different groups were presented.
    Sars Cov 2 Strains, supplied by sino biological, used in various techniques. Bioz Stars score: 86/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
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    Average 86 stars, based on 1 article reviews
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    94
    Sino Biological sars cov 2 rbd
    RU169 output clone diversity Using the <t>SARS-CoV-2</t> RBD as the target of library panning and FACS selection for screen RU169 produced a high number of unique clones, indicating high, unexplored, diversity in the output.
    Sars Cov 2 Rbd, supplied by Sino Biological, used in various techniques. Bioz Stars score: 94/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/result/sars cov 2 rbd/product/Sino Biological
    Average 94 stars, based on 1 article reviews
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    86
    sino biological sars cov 2 specific peptides
    Kinetics of SARS-CoV2 specific CD4 + and CD8 + T cell responses in COVID-19 asymptomatic patients. PBMCs of healthy control ( n = 8) and asymptomatic COVID-19 patients ( n = 10) were stimulated with <t>SARS-CoV-2</t> dominant antigen (S1, S2, and nucleoprotein, N) cocktails for 44 h, Golgi-Plug containing Golgi-stop and DNAase were added into cell culture for another 4 h. Representative samples were from Healthy (#3), Asymptomatic (#3). a FACS plot examples of IFNγ + CD4 + T cells in total live CD4 + T cells, gated on total live CD4 + T cells. b Bar graph shows the frequency of IFNγ + CD4 + T cells in total CD4 + T cells after stimulation, summarized from ( a ). c FACS plot examples of GZMB + Perforin + CD4 + T cells in total IFNγ + CD4 + T cells, gated on total live IFNγ + CD4 + T cells. d Frequency of GZMB + Perforin + CD4 + T cells in total IFNγ + CD4 + T cells, summarized from ( c ). e FACS plot examples of IFNγ + CD8 + T cells in total live CD8 + T cells, gated on total live CD8 + T cells. f Bar graph shows the frequency of IFNγ + CD8 + T cells in total CD8 + T cells after stimulation, summarized from ( e ). g FACS plot examples of GZMB + Perforin + CD8 + T cells in total IFNγ + CD8 + T cells, gated on total live IFNγ + CD8 + T cells. h Frequency of GZMB + Perforin + CD8 + T cells in total IFNγ + CD8 + T cells, summarized from ( g ). Bars represent the mean ± SEM. P values were calculated based on Bonferroni of one-way ANOVA analysis. There was no statistically significant difference among different stage of asymptomatic patients
    Sars Cov 2 Specific Peptides, supplied by sino biological, used in various techniques. Bioz Stars score: 86/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
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    98
    Sino Biological sars cov 2 rbd protein
    Immunogenicity evaluation of a single mRNA-RBD vaccination. a – c Groups of BALB/c mice ( n = 6) were immunized with a single injection of mRNA-RBD at different doses or with a placebo via the i.m. route. Sera at 4 weeks post immunization were collected. <t>SARS-CoV-2</t> RBD-specific IgG ( a ) and neutralizing antibody titers in sera against pseudovirus ( b ) and live virus ( c ) infection were determined. d – h C57BL/6 mice ( n = 6) were inoculated with a single mRNA-RBD vaccination or a placebo. Serum samples were collected from mice at 4 weeks following vaccination. RBD-specific IgG titers and pseudovirus-neutralizing antibodies were measured as shown in d and e , respectively. f An ELISPOT assay was performed to evaluate the capacity of splenocytes to secrete IFNγ following re-stimulation with SARS-CoV-2 RBD peptide pools. g , h An ICS assay was conducted to quantify the proportions of IFNγ-secreting CD8 + ( g ) and CD4 + ( h ) T cells. mRNA-RBD-L indicates the low dose (2 μg). mRNA-RBD-H indicates the high dose (15 μg). HCS represents human convalescent sera. Data are means ± SEM (standard error of the mean). Comparisons were performed by Student’s t -test (unpaired, two tailed). Placebo animals = black circles; mRNA-RBD-L vaccinated animals = blue triangles; mRNA-RBD-H vaccinated animals = red squares; HCS = brown circles; dotted line = the limit of detection. Data are one representative result of two independent experiments. Source data are provided as a Source Data file.
    Sars Cov 2 Rbd Protein, supplied by Sino Biological, used in various techniques. Bioz Stars score: 98/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
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    Image Search Results


    Impact of Spike G614 variant on the seropositivity of SARS-CoV-2 infected patients. (A-B) Protein structure of Spike obtained from the Protein Data Bank (PDB ID6zb5 for D614 variant and PDB ID6xs6 for G614 variant). (A) The region in which the amino acid 614 was localized (square) on the trimer of Spike molecules (in green, orange and yellow) was further analyzed in D. (B) Predicted residue interactions with electrostatic (middle panels) and lipophibic (right panels) properties were compared between Spike D614 and G614 variants. (C) Sera from COVID-19 patients developing mild (blue, n=17), moderate (green, n=13) and severe (orange, n=15) forms of COVID-19 were re-evaluated in the SARS-CoV-2 serological assay using Spike D614 and G614 expressing HEK cells. Specific binding of IgG (circles), IgM (squares) and IgA (diamonds) were represented and thresholds (grey boxes) were obtained with the basal levels of Ig binding from control sera tested in Figure 2A . (D) Percentage of patients with decreased seropositivity against D614 and G614 variants from the different groups were presented.

    Journal: bioRxiv

    Article Title: SARS-CoV2 envelop proteins reshape the serological responses of COVID-19 patients

    doi: 10.1101/2021.02.15.431237

    Figure Lengend Snippet: Impact of Spike G614 variant on the seropositivity of SARS-CoV-2 infected patients. (A-B) Protein structure of Spike obtained from the Protein Data Bank (PDB ID6zb5 for D614 variant and PDB ID6xs6 for G614 variant). (A) The region in which the amino acid 614 was localized (square) on the trimer of Spike molecules (in green, orange and yellow) was further analyzed in D. (B) Predicted residue interactions with electrostatic (middle panels) and lipophibic (right panels) properties were compared between Spike D614 and G614 variants. (C) Sera from COVID-19 patients developing mild (blue, n=17), moderate (green, n=13) and severe (orange, n=15) forms of COVID-19 were re-evaluated in the SARS-CoV-2 serological assay using Spike D614 and G614 expressing HEK cells. Specific binding of IgG (circles), IgM (squares) and IgA (diamonds) were represented and thresholds (grey boxes) were obtained with the basal levels of Ig binding from control sera tested in Figure 2A . (D) Percentage of patients with decreased seropositivity against D614 and G614 variants from the different groups were presented.

    Article Snippet: At the current time of massive vaccination against Spike using RNA approach developed by Pfizer-BioNTech and Moderna ( , ); and the spreading of novel SARS-CoV-2 strains carrying Spike mutations, our serological assay represents a reliable test to verify the immunization efficiency during the vaccination and to analyze the impact of these Spike mutations on antibody responses.

    Techniques: Variant Assay, Infection, Serologic Assay, Expressing, Binding Assay

    Development of a serological assay that mimics surface expression of SARS-CoV-2 membrane proteins. (A) Strategy and workflow of the SARS-CoV-2 serological assay developed using flow cytometry. HEK cells transiently transfected with viral genes encoding membrane proteins ( i.e. E, M and Spike) were used as matrix for the detection of antibodies present in sera obtained from COVID-19 patients. The binding of anti-viral membrane proteins antibodies of IgG, IgM and IgA subtypes was analyzed by flow cytometry. Results were expressed as specific antibody binding to viral membrane proteins as non-specific binging was determined using non-transfected HEK cells. (B-D) Expression of viral membrane proteins at the surface of HEK cells. HEK cells transfected with viral genes encoding E, M and Spike membrane proteins tagged with two Strep Tag motifs were analyzed for viral protein expression by western-blot (B) and flow cytometry (C-D) using strep-tactin, streptavidin or anti-Spike antibody. Percentage of positive cells and protein expression levels were represented in (C) and (D) . (E-F) Detection of immunoglobulin IgG, IgM and IgA binding at the surface of HEK cells expressing viral membrane proteins by flow cytometry. Positive sera from SARS-CoV-2 infected patients (CTR#4 and COVID+) were incubated with HEK cells expressing E, M and Spike viral proteins at different dilutions. Serum from a healthy donor (PRECOV) obtained before January 2020 was used as a negative control. The binding of IgG, M and A immunoglobulins were analyzed by flow cytometry using secondary antibodies specific for each Ig subtype. Representative flow cytometry histograms were shown for Spike in (E) and results were presented as specific Ig binding relative to HEK cells (F) .

    Journal: bioRxiv

    Article Title: SARS-CoV2 envelop proteins reshape the serological responses of COVID-19 patients

    doi: 10.1101/2021.02.15.431237

    Figure Lengend Snippet: Development of a serological assay that mimics surface expression of SARS-CoV-2 membrane proteins. (A) Strategy and workflow of the SARS-CoV-2 serological assay developed using flow cytometry. HEK cells transiently transfected with viral genes encoding membrane proteins ( i.e. E, M and Spike) were used as matrix for the detection of antibodies present in sera obtained from COVID-19 patients. The binding of anti-viral membrane proteins antibodies of IgG, IgM and IgA subtypes was analyzed by flow cytometry. Results were expressed as specific antibody binding to viral membrane proteins as non-specific binging was determined using non-transfected HEK cells. (B-D) Expression of viral membrane proteins at the surface of HEK cells. HEK cells transfected with viral genes encoding E, M and Spike membrane proteins tagged with two Strep Tag motifs were analyzed for viral protein expression by western-blot (B) and flow cytometry (C-D) using strep-tactin, streptavidin or anti-Spike antibody. Percentage of positive cells and protein expression levels were represented in (C) and (D) . (E-F) Detection of immunoglobulin IgG, IgM and IgA binding at the surface of HEK cells expressing viral membrane proteins by flow cytometry. Positive sera from SARS-CoV-2 infected patients (CTR#4 and COVID+) were incubated with HEK cells expressing E, M and Spike viral proteins at different dilutions. Serum from a healthy donor (PRECOV) obtained before January 2020 was used as a negative control. The binding of IgG, M and A immunoglobulins were analyzed by flow cytometry using secondary antibodies specific for each Ig subtype. Representative flow cytometry histograms were shown for Spike in (E) and results were presented as specific Ig binding relative to HEK cells (F) .

    Article Snippet: At the current time of massive vaccination against Spike using RNA approach developed by Pfizer-BioNTech and Moderna ( , ); and the spreading of novel SARS-CoV-2 strains carrying Spike mutations, our serological assay represents a reliable test to verify the immunization efficiency during the vaccination and to analyze the impact of these Spike mutations on antibody responses.

    Techniques: Serologic Assay, Expressing, Flow Cytometry, Transfection, Binding Assay, Strep-tag, Western Blot, Infection, Incubation, Negative Control

    Serological profile of SARS-CoV-2 infected patients against viral membrane proteins according to the disease severity. (A-B) Sera from control donors and SARS-CoV-2 infected patients were tested for their positivity against viral Spike (A) and M proteins (B) using the SARS-CoV-2 serological assay described in Figure 1 . Control sera were obtained from healthy donors and collected before January 2020 (CTR, n=38); and from patients infected with other coronaviruses (n=5) or patients with hyperimmunoglobulin M syndrome (n=5) (included in CTR2, n=10). Sera collected after January 2020 were obtained from donors without symptoms (no symptom, n=26); with symptoms related to SARS-CoV-2 infection (symptoms, n=4); and from patients positive for SARS-CoV-2 infection (COVID+) and developing mild (blue, n=22), moderate (green, n=14) and severe (orange, n=15) forms of COVID-19. Specific binding of IgG (circles), IgM (squares) and IgA (diamonds) were represented and thresholds (grey boxes) were obtained with the basal levels of Ig binding from control sera. (C) The percentage of seropositive patients from the different groups were calculated using thresholds obtained in (A-B) . (D) Correlation between anti-Spike and anti-M Ig responses were represented including sera from COVID-19 patients developing mild (blue, n=22), moderate (green, n=14) and severe (orange, n=15) forms of COVID-19.

    Journal: bioRxiv

    Article Title: SARS-CoV2 envelop proteins reshape the serological responses of COVID-19 patients

    doi: 10.1101/2021.02.15.431237

    Figure Lengend Snippet: Serological profile of SARS-CoV-2 infected patients against viral membrane proteins according to the disease severity. (A-B) Sera from control donors and SARS-CoV-2 infected patients were tested for their positivity against viral Spike (A) and M proteins (B) using the SARS-CoV-2 serological assay described in Figure 1 . Control sera were obtained from healthy donors and collected before January 2020 (CTR, n=38); and from patients infected with other coronaviruses (n=5) or patients with hyperimmunoglobulin M syndrome (n=5) (included in CTR2, n=10). Sera collected after January 2020 were obtained from donors without symptoms (no symptom, n=26); with symptoms related to SARS-CoV-2 infection (symptoms, n=4); and from patients positive for SARS-CoV-2 infection (COVID+) and developing mild (blue, n=22), moderate (green, n=14) and severe (orange, n=15) forms of COVID-19. Specific binding of IgG (circles), IgM (squares) and IgA (diamonds) were represented and thresholds (grey boxes) were obtained with the basal levels of Ig binding from control sera. (C) The percentage of seropositive patients from the different groups were calculated using thresholds obtained in (A-B) . (D) Correlation between anti-Spike and anti-M Ig responses were represented including sera from COVID-19 patients developing mild (blue, n=22), moderate (green, n=14) and severe (orange, n=15) forms of COVID-19.

    Article Snippet: At the current time of massive vaccination against Spike using RNA approach developed by Pfizer-BioNTech and Moderna ( , ); and the spreading of novel SARS-CoV-2 strains carrying Spike mutations, our serological assay represents a reliable test to verify the immunization efficiency during the vaccination and to analyze the impact of these Spike mutations on antibody responses.

    Techniques: Infection, Serologic Assay, Binding Assay

    RU169 output clone diversity Using the SARS-CoV-2 RBD as the target of library panning and FACS selection for screen RU169 produced a high number of unique clones, indicating high, unexplored, diversity in the output.

    Journal: bioRxiv

    Article Title: Antibodies that potently inhibit or enhance SARS-CoV-2 spike protein-ACE2 interaction isolated from synthetic single-chain antibody libraries

    doi: 10.1101/2020.07.27.224089

    Figure Lengend Snippet: RU169 output clone diversity Using the SARS-CoV-2 RBD as the target of library panning and FACS selection for screen RU169 produced a high number of unique clones, indicating high, unexplored, diversity in the output.

    Article Snippet: ACE2-S1 inhibition assayThe ability of RBD-binding antibodies to block the high-affinity interaction between SARS-CoV-2 RBD and human ACE2 protein was tested in a bead-binding assay.

    Techniques: FACS, Selection, Produced, Clone Assay

    BLI kinetics of selected scFv clones from the RU169 RBD screen. scFv were cloned into an AviTag™ biotinylation vector, as described in the Materials and Methods, expressed and purified by Ni-NTA resin. scFv were loaded onto a streptavidin BLI sensor and the association/dissociation kinetics of binding to soluble SARS-CoV-2 S1 trimer (100 nM) were measured using BLI. The K D of the scFvs for the S1 target ranged from 1 nM to 400 nM.

    Journal: bioRxiv

    Article Title: Antibodies that potently inhibit or enhance SARS-CoV-2 spike protein-ACE2 interaction isolated from synthetic single-chain antibody libraries

    doi: 10.1101/2020.07.27.224089

    Figure Lengend Snippet: BLI kinetics of selected scFv clones from the RU169 RBD screen. scFv were cloned into an AviTag™ biotinylation vector, as described in the Materials and Methods, expressed and purified by Ni-NTA resin. scFv were loaded onto a streptavidin BLI sensor and the association/dissociation kinetics of binding to soluble SARS-CoV-2 S1 trimer (100 nM) were measured using BLI. The K D of the scFvs for the S1 target ranged from 1 nM to 400 nM.

    Article Snippet: ACE2-S1 inhibition assayThe ability of RBD-binding antibodies to block the high-affinity interaction between SARS-CoV-2 RBD and human ACE2 protein was tested in a bead-binding assay.

    Techniques: Clone Assay, Plasmid Preparation, Purification, Binding Assay

    Anti-RBD clones in IgG1 format form long-lived complexes with SARS-CoV-2 S1 trimer and potently inhibit the interaction with ACE2 in vitro . A. Dissociation kinetics of IgG1 anti-RBD clones from SARS-CoV-2 S1 trimer. Biotinylated SARS-CoV-2 S1 trimer was bound to a streptavidin BLI sensor. IgG1 anti-RBD clones were bound (100 nM) and the dissociation followed for 4 hours in PBS at 25°C. B. ACE2-S1 Dynabead assay with molar equivalents of mAb clones to S1 trimer.

    Journal: bioRxiv

    Article Title: Antibodies that potently inhibit or enhance SARS-CoV-2 spike protein-ACE2 interaction isolated from synthetic single-chain antibody libraries

    doi: 10.1101/2020.07.27.224089

    Figure Lengend Snippet: Anti-RBD clones in IgG1 format form long-lived complexes with SARS-CoV-2 S1 trimer and potently inhibit the interaction with ACE2 in vitro . A. Dissociation kinetics of IgG1 anti-RBD clones from SARS-CoV-2 S1 trimer. Biotinylated SARS-CoV-2 S1 trimer was bound to a streptavidin BLI sensor. IgG1 anti-RBD clones were bound (100 nM) and the dissociation followed for 4 hours in PBS at 25°C. B. ACE2-S1 Dynabead assay with molar equivalents of mAb clones to S1 trimer.

    Article Snippet: ACE2-S1 inhibition assayThe ability of RBD-binding antibodies to block the high-affinity interaction between SARS-CoV-2 RBD and human ACE2 protein was tested in a bead-binding assay.

    Techniques: Clone Assay, In Vitro

    FACS strategy of screen RU167 for scFv inhibiting the SARS-CoV-2 RBD/ACE2 interaction The FACS-based screening strategy for screen RU167 to isolate antibodies that bound SARS-CoV-2 RBD and specifically inhibited co-binding of RBD to the human ACE2 protein. The viral RBD and the ACE2 protein were labeled with different fluorophores (A). Binding to cells expressing scFv clones that bound RBD and blocking the ACE2-binding site (B) would be observed and gated positively for in the FACS plot for events which were RBD-dye HIGH and ACE2-dye LOW (C).

    Journal: bioRxiv

    Article Title: Antibodies that potently inhibit or enhance SARS-CoV-2 spike protein-ACE2 interaction isolated from synthetic single-chain antibody libraries

    doi: 10.1101/2020.07.27.224089

    Figure Lengend Snippet: FACS strategy of screen RU167 for scFv inhibiting the SARS-CoV-2 RBD/ACE2 interaction The FACS-based screening strategy for screen RU167 to isolate antibodies that bound SARS-CoV-2 RBD and specifically inhibited co-binding of RBD to the human ACE2 protein. The viral RBD and the ACE2 protein were labeled with different fluorophores (A). Binding to cells expressing scFv clones that bound RBD and blocking the ACE2-binding site (B) would be observed and gated positively for in the FACS plot for events which were RBD-dye HIGH and ACE2-dye LOW (C).

    Article Snippet: ACE2-S1 inhibition assayThe ability of RBD-binding antibodies to block the high-affinity interaction between SARS-CoV-2 RBD and human ACE2 protein was tested in a bead-binding assay.

    Techniques: FACS, Binding Assay, Labeling, Expressing, Clone Assay, Blocking Assay

    BLI kinetics of anti-RBD diabodies AviTag™ biotinylated SARS-CoV-2 S1 trimer was loaded onto a BLI sensor and the association/dissociation kinetics of binding to anti-RBD diabodies (100 nM) were measured using BLI. The K D s of the dbs to the S1 target ranged from 84 pM to 1 nM.

    Journal: bioRxiv

    Article Title: Antibodies that potently inhibit or enhance SARS-CoV-2 spike protein-ACE2 interaction isolated from synthetic single-chain antibody libraries

    doi: 10.1101/2020.07.27.224089

    Figure Lengend Snippet: BLI kinetics of anti-RBD diabodies AviTag™ biotinylated SARS-CoV-2 S1 trimer was loaded onto a BLI sensor and the association/dissociation kinetics of binding to anti-RBD diabodies (100 nM) were measured using BLI. The K D s of the dbs to the S1 target ranged from 84 pM to 1 nM.

    Article Snippet: ACE2-S1 inhibition assayThe ability of RBD-binding antibodies to block the high-affinity interaction between SARS-CoV-2 RBD and human ACE2 protein was tested in a bead-binding assay.

    Techniques: Binding Assay

    Cytometry plots of ACE2-S1 Dynabead assay of anti-RBD diabodies The degree of inhibition of the ACE2 and SARS-CoV-2 S1 trimer interaction by stoichiometric amounts of anti-RBD diabodies was determined using a Dynabead assay as described in the Materials and Methods. The degree of bead fluorescence was indicative of the amount of dye-labeled S1 trimer that was bound to ACE2. Inhibition of the interaction by anti-RBD diabodies resulted in a reduction in fluorescence. The first panel is the SSC/FSC indicating the P1 gating of beads. The second panel is the biotin-blocked control (no ACE2/S1 interaction) and the third panel is the no anti-RBD control (maximum ACE2/S1 interaction. Each subsequent row represents a db clone at 1:1, 5:1 and 10:1 stoichiometric ratios to the soluble SARS-CoV-2 S1 trimer. The data are summarized graphically in Figure 3 .

    Journal: bioRxiv

    Article Title: Antibodies that potently inhibit or enhance SARS-CoV-2 spike protein-ACE2 interaction isolated from synthetic single-chain antibody libraries

    doi: 10.1101/2020.07.27.224089

    Figure Lengend Snippet: Cytometry plots of ACE2-S1 Dynabead assay of anti-RBD diabodies The degree of inhibition of the ACE2 and SARS-CoV-2 S1 trimer interaction by stoichiometric amounts of anti-RBD diabodies was determined using a Dynabead assay as described in the Materials and Methods. The degree of bead fluorescence was indicative of the amount of dye-labeled S1 trimer that was bound to ACE2. Inhibition of the interaction by anti-RBD diabodies resulted in a reduction in fluorescence. The first panel is the SSC/FSC indicating the P1 gating of beads. The second panel is the biotin-blocked control (no ACE2/S1 interaction) and the third panel is the no anti-RBD control (maximum ACE2/S1 interaction. Each subsequent row represents a db clone at 1:1, 5:1 and 10:1 stoichiometric ratios to the soluble SARS-CoV-2 S1 trimer. The data are summarized graphically in Figure 3 .

    Article Snippet: ACE2-S1 inhibition assayThe ability of RBD-binding antibodies to block the high-affinity interaction between SARS-CoV-2 RBD and human ACE2 protein was tested in a bead-binding assay.

    Techniques: Cytometry, Inhibition, Fluorescence, Labeling

    Kinetics of SARS-CoV2 specific CD4 + and CD8 + T cell responses in COVID-19 asymptomatic patients. PBMCs of healthy control ( n = 8) and asymptomatic COVID-19 patients ( n = 10) were stimulated with SARS-CoV-2 dominant antigen (S1, S2, and nucleoprotein, N) cocktails for 44 h, Golgi-Plug containing Golgi-stop and DNAase were added into cell culture for another 4 h. Representative samples were from Healthy (#3), Asymptomatic (#3). a FACS plot examples of IFNγ + CD4 + T cells in total live CD4 + T cells, gated on total live CD4 + T cells. b Bar graph shows the frequency of IFNγ + CD4 + T cells in total CD4 + T cells after stimulation, summarized from ( a ). c FACS plot examples of GZMB + Perforin + CD4 + T cells in total IFNγ + CD4 + T cells, gated on total live IFNγ + CD4 + T cells. d Frequency of GZMB + Perforin + CD4 + T cells in total IFNγ + CD4 + T cells, summarized from ( c ). e FACS plot examples of IFNγ + CD8 + T cells in total live CD8 + T cells, gated on total live CD8 + T cells. f Bar graph shows the frequency of IFNγ + CD8 + T cells in total CD8 + T cells after stimulation, summarized from ( e ). g FACS plot examples of GZMB + Perforin + CD8 + T cells in total IFNγ + CD8 + T cells, gated on total live IFNγ + CD8 + T cells. h Frequency of GZMB + Perforin + CD8 + T cells in total IFNγ + CD8 + T cells, summarized from ( g ). Bars represent the mean ± SEM. P values were calculated based on Bonferroni of one-way ANOVA analysis. There was no statistically significant difference among different stage of asymptomatic patients

    Journal: Signal Transduction and Targeted Therapy

    Article Title: The dichotomous and incomplete adaptive immunity in COVID-19 patients with different disease severity

    doi: 10.1038/s41392-021-00525-3

    Figure Lengend Snippet: Kinetics of SARS-CoV2 specific CD4 + and CD8 + T cell responses in COVID-19 asymptomatic patients. PBMCs of healthy control ( n = 8) and asymptomatic COVID-19 patients ( n = 10) were stimulated with SARS-CoV-2 dominant antigen (S1, S2, and nucleoprotein, N) cocktails for 44 h, Golgi-Plug containing Golgi-stop and DNAase were added into cell culture for another 4 h. Representative samples were from Healthy (#3), Asymptomatic (#3). a FACS plot examples of IFNγ + CD4 + T cells in total live CD4 + T cells, gated on total live CD4 + T cells. b Bar graph shows the frequency of IFNγ + CD4 + T cells in total CD4 + T cells after stimulation, summarized from ( a ). c FACS plot examples of GZMB + Perforin + CD4 + T cells in total IFNγ + CD4 + T cells, gated on total live IFNγ + CD4 + T cells. d Frequency of GZMB + Perforin + CD4 + T cells in total IFNγ + CD4 + T cells, summarized from ( c ). e FACS plot examples of IFNγ + CD8 + T cells in total live CD8 + T cells, gated on total live CD8 + T cells. f Bar graph shows the frequency of IFNγ + CD8 + T cells in total CD8 + T cells after stimulation, summarized from ( e ). g FACS plot examples of GZMB + Perforin + CD8 + T cells in total IFNγ + CD8 + T cells, gated on total live IFNγ + CD8 + T cells. h Frequency of GZMB + Perforin + CD8 + T cells in total IFNγ + CD8 + T cells, summarized from ( g ). Bars represent the mean ± SEM. P values were calculated based on Bonferroni of one-way ANOVA analysis. There was no statistically significant difference among different stage of asymptomatic patients

    Article Snippet: Intracellular cytokine staining and flow cytometry PBMCs in wells of a 96-well plate with 100 μL complete RPMI 1640 and 10% human AB serum (Gemini Bioproducts) and Pen-Strep, were incubated 44 h with 1 μM of recombinant proteins (S1, S2, and nucleoprotein, N) or were incubated 14 h with 100 ng/ml of SARS-CoV-2 specific peptides (Table ).

    Techniques: Cell Culture, FACS

    SARS-CoV2 specific CD4 + and CD8 + T cell responses in COVID-19 convalescent patients. PBMCs of healthy control ( n =8) and recovered COVID-19 patients ( n =64) were stimulated with SARS-CoV-2 dominant antigen (S1, S2 and nucleoprotein, N) cocktails for 44h, Golgi-Plug containing Golgi-stop and DNase were added into cell culture for another 4h. Samples of a , c , e , and g were from Healthy (#3), Asymptomatic (#4), Mild (#8), Moderate (#13), severe (#6). a FACS plot examples of IFNγ + CD4 + T cells in total live CD4 + T cells, gated on total live CD4 + T cells. b Bar graph shows the frequency of IFNγ + CD4 + T cells in total CD4 + T cells after stimulation, summarized from ( a ). c FACS plot examples of GZMB + Perforin + CD4 + T cells in total IFNγ + CD4 + T cells, gated on total live IFNγ + CD4 + T cells. d Frequency of GZMB + Perforin + CD4 + T cells in total IFNγ + CD4 + T cells, summarized from ( c ). e FACS plot examples of IFNγ + CD8 + T cells in total live CD8 + T cells, gated on total live CD8 + T cells. f Bar graph shows the frequency of IFNγ + CD8 + T cells in total CD8 + T cells after stimulation, summarized from ( e ). g FACS plot examples of GZMB + Perforin + CD8 + T cells in total IFNγ + CD8 + T cells, gated on total live IFNγ + CD8 + T cells. h Frequency of GZMB + Perforin + CD8 + T cells in total IFNγ + CD8 + T cells, summarized from ( g ). Bars represent the mean±SEM. P values were calculated based on Bonferroni of one-way ANOVA analysis. *** p

    Journal: Signal Transduction and Targeted Therapy

    Article Title: The dichotomous and incomplete adaptive immunity in COVID-19 patients with different disease severity

    doi: 10.1038/s41392-021-00525-3

    Figure Lengend Snippet: SARS-CoV2 specific CD4 + and CD8 + T cell responses in COVID-19 convalescent patients. PBMCs of healthy control ( n =8) and recovered COVID-19 patients ( n =64) were stimulated with SARS-CoV-2 dominant antigen (S1, S2 and nucleoprotein, N) cocktails for 44h, Golgi-Plug containing Golgi-stop and DNase were added into cell culture for another 4h. Samples of a , c , e , and g were from Healthy (#3), Asymptomatic (#4), Mild (#8), Moderate (#13), severe (#6). a FACS plot examples of IFNγ + CD4 + T cells in total live CD4 + T cells, gated on total live CD4 + T cells. b Bar graph shows the frequency of IFNγ + CD4 + T cells in total CD4 + T cells after stimulation, summarized from ( a ). c FACS plot examples of GZMB + Perforin + CD4 + T cells in total IFNγ + CD4 + T cells, gated on total live IFNγ + CD4 + T cells. d Frequency of GZMB + Perforin + CD4 + T cells in total IFNγ + CD4 + T cells, summarized from ( c ). e FACS plot examples of IFNγ + CD8 + T cells in total live CD8 + T cells, gated on total live CD8 + T cells. f Bar graph shows the frequency of IFNγ + CD8 + T cells in total CD8 + T cells after stimulation, summarized from ( e ). g FACS plot examples of GZMB + Perforin + CD8 + T cells in total IFNγ + CD8 + T cells, gated on total live IFNγ + CD8 + T cells. h Frequency of GZMB + Perforin + CD8 + T cells in total IFNγ + CD8 + T cells, summarized from ( g ). Bars represent the mean±SEM. P values were calculated based on Bonferroni of one-way ANOVA analysis. *** p

    Article Snippet: Intracellular cytokine staining and flow cytometry PBMCs in wells of a 96-well plate with 100 μL complete RPMI 1640 and 10% human AB serum (Gemini Bioproducts) and Pen-Strep, were incubated 44 h with 1 μM of recombinant proteins (S1, S2, and nucleoprotein, N) or were incubated 14 h with 100 ng/ml of SARS-CoV-2 specific peptides (Table ).

    Techniques: Cell Culture, FACS

    Immunogenicity evaluation of a single mRNA-RBD vaccination. a – c Groups of BALB/c mice ( n = 6) were immunized with a single injection of mRNA-RBD at different doses or with a placebo via the i.m. route. Sera at 4 weeks post immunization were collected. SARS-CoV-2 RBD-specific IgG ( a ) and neutralizing antibody titers in sera against pseudovirus ( b ) and live virus ( c ) infection were determined. d – h C57BL/6 mice ( n = 6) were inoculated with a single mRNA-RBD vaccination or a placebo. Serum samples were collected from mice at 4 weeks following vaccination. RBD-specific IgG titers and pseudovirus-neutralizing antibodies were measured as shown in d and e , respectively. f An ELISPOT assay was performed to evaluate the capacity of splenocytes to secrete IFNγ following re-stimulation with SARS-CoV-2 RBD peptide pools. g , h An ICS assay was conducted to quantify the proportions of IFNγ-secreting CD8 + ( g ) and CD4 + ( h ) T cells. mRNA-RBD-L indicates the low dose (2 μg). mRNA-RBD-H indicates the high dose (15 μg). HCS represents human convalescent sera. Data are means ± SEM (standard error of the mean). Comparisons were performed by Student’s t -test (unpaired, two tailed). Placebo animals = black circles; mRNA-RBD-L vaccinated animals = blue triangles; mRNA-RBD-H vaccinated animals = red squares; HCS = brown circles; dotted line = the limit of detection. Data are one representative result of two independent experiments. Source data are provided as a Source Data file.

    Journal: Nature Communications

    Article Title: A single-dose mRNA vaccine provides a long-term protection for hACE2 transgenic mice from SARS-CoV-2

    doi: 10.1038/s41467-021-21037-2

    Figure Lengend Snippet: Immunogenicity evaluation of a single mRNA-RBD vaccination. a – c Groups of BALB/c mice ( n = 6) were immunized with a single injection of mRNA-RBD at different doses or with a placebo via the i.m. route. Sera at 4 weeks post immunization were collected. SARS-CoV-2 RBD-specific IgG ( a ) and neutralizing antibody titers in sera against pseudovirus ( b ) and live virus ( c ) infection were determined. d – h C57BL/6 mice ( n = 6) were inoculated with a single mRNA-RBD vaccination or a placebo. Serum samples were collected from mice at 4 weeks following vaccination. RBD-specific IgG titers and pseudovirus-neutralizing antibodies were measured as shown in d and e , respectively. f An ELISPOT assay was performed to evaluate the capacity of splenocytes to secrete IFNγ following re-stimulation with SARS-CoV-2 RBD peptide pools. g , h An ICS assay was conducted to quantify the proportions of IFNγ-secreting CD8 + ( g ) and CD4 + ( h ) T cells. mRNA-RBD-L indicates the low dose (2 μg). mRNA-RBD-H indicates the high dose (15 μg). HCS represents human convalescent sera. Data are means ± SEM (standard error of the mean). Comparisons were performed by Student’s t -test (unpaired, two tailed). Placebo animals = black circles; mRNA-RBD-L vaccinated animals = blue triangles; mRNA-RBD-H vaccinated animals = red squares; HCS = brown circles; dotted line = the limit of detection. Data are one representative result of two independent experiments. Source data are provided as a Source Data file.

    Article Snippet: Briefly, a monoclonal antibody specific for SARS-CoV-2 RBD protein was pre-coated onto plate wells.

    Techniques: Mouse Assay, Injection, Infection, Enzyme-linked Immunospot, Two Tailed Test

    Duration and long-term protection of humoral response induced by mRNA-RBD. a Passive immunization and challenge schedule. The blue and red arrow indicates the time of vaccination and sera transfer, respectively. b , c Groups of BALB/c mice ( n = 10) received 15 μg of mRNA-RBD or a placebo. Half of the mice per group were euthanized at 8 weeks (short term) post vaccination, and massive sera were collected for further passive immunization. The other mice of the group were bled as desired and eventually euthanized at 26 weeks (long term) post vaccination to collect massive sera for further passive immunization. All serum samples were detected for IgG ( b ) and neutralizing antibodies ( c ) titers. d–e hACE2 transgenic mice ( n = 5) were administered 350 μl per mouse of pooled short- and long-term immune sera and one day later were challenged with 1 × 10 5 FFU of SARS-CoV-2 via the i.n. route. d The hACE2 mice weight change was recorded after challenge. e Virus titers in lung. mRNA-RBD-H indicates the high-dose vaccine (15 μg). Data are means ± SEM (standard error of the mean). Comparisons were performed by Student’s t -test (unpaired, two tailed). Placebo animals = black circles; animals for long-term study = blue triangles; animals for short-term study = red squares; dotted line = the limit of detection. Data are one representative result of two independent experiments. Source data are provided as a Source Data file.

    Journal: Nature Communications

    Article Title: A single-dose mRNA vaccine provides a long-term protection for hACE2 transgenic mice from SARS-CoV-2

    doi: 10.1038/s41467-021-21037-2

    Figure Lengend Snippet: Duration and long-term protection of humoral response induced by mRNA-RBD. a Passive immunization and challenge schedule. The blue and red arrow indicates the time of vaccination and sera transfer, respectively. b , c Groups of BALB/c mice ( n = 10) received 15 μg of mRNA-RBD or a placebo. Half of the mice per group were euthanized at 8 weeks (short term) post vaccination, and massive sera were collected for further passive immunization. The other mice of the group were bled as desired and eventually euthanized at 26 weeks (long term) post vaccination to collect massive sera for further passive immunization. All serum samples were detected for IgG ( b ) and neutralizing antibodies ( c ) titers. d–e hACE2 transgenic mice ( n = 5) were administered 350 μl per mouse of pooled short- and long-term immune sera and one day later were challenged with 1 × 10 5 FFU of SARS-CoV-2 via the i.n. route. d The hACE2 mice weight change was recorded after challenge. e Virus titers in lung. mRNA-RBD-H indicates the high-dose vaccine (15 μg). Data are means ± SEM (standard error of the mean). Comparisons were performed by Student’s t -test (unpaired, two tailed). Placebo animals = black circles; animals for long-term study = blue triangles; animals for short-term study = red squares; dotted line = the limit of detection. Data are one representative result of two independent experiments. Source data are provided as a Source Data file.

    Article Snippet: Briefly, a monoclonal antibody specific for SARS-CoV-2 RBD protein was pre-coated onto plate wells.

    Techniques: Mouse Assay, Transgenic Assay, Two Tailed Test

    Protection efficacy of mRNA-RBD in hACE2 transgenic mice against SARS-CoV-2. a-d Groups of hACE2 transgenic mice ( n = 6) received one (prime group) or two (boost group) doses of mRNA-RBD-H or placebo via the i.m. route. Four weeks post initial vaccination, mice were challenged with 1 × 10 5 FFU of SARS-CoV-2 virus. a Mice immunization and challenge schedule. The blue arrows indicate the time of vaccination. b , c Sera collected at 4 weeks post initial vaccination were examined for IgG ( b ) and neutralizing antibody ( c ) titers. d Mice weight change after challenge. e Virus titers in lungs of challenged mice ( n = 4). f Representative histopathology (H E) of lungs in SARS-CoV-2-infected hACE2 mice (5 dpi). Infiltration of lymphocytes within alveolar spaces is indicated by yellow arrows. Scale bar, 100 μm. g Representative immunohistochemistry (IHC) of lung tissues with SARS-CoV-2 N-specific monoclonal antibodies. Virus is indicated by yellow arrows. Scale bar, 100 μm. mRNA-RBD-H indicates the high-dose vaccine (15 μg). Data are means ± SEM (standard error of the mean). Comparisons were performed by Student’s t -test (unpaired, two tailed). Placebo animals = black circles; one injection-animals = blue triangles; two injections-vaccinated animals = red squares; dotted line = the limit of detection. Data are one representative result of two independent experiments. Source data are provided as a Source Data file.

    Journal: Nature Communications

    Article Title: A single-dose mRNA vaccine provides a long-term protection for hACE2 transgenic mice from SARS-CoV-2

    doi: 10.1038/s41467-021-21037-2

    Figure Lengend Snippet: Protection efficacy of mRNA-RBD in hACE2 transgenic mice against SARS-CoV-2. a-d Groups of hACE2 transgenic mice ( n = 6) received one (prime group) or two (boost group) doses of mRNA-RBD-H or placebo via the i.m. route. Four weeks post initial vaccination, mice were challenged with 1 × 10 5 FFU of SARS-CoV-2 virus. a Mice immunization and challenge schedule. The blue arrows indicate the time of vaccination. b , c Sera collected at 4 weeks post initial vaccination were examined for IgG ( b ) and neutralizing antibody ( c ) titers. d Mice weight change after challenge. e Virus titers in lungs of challenged mice ( n = 4). f Representative histopathology (H E) of lungs in SARS-CoV-2-infected hACE2 mice (5 dpi). Infiltration of lymphocytes within alveolar spaces is indicated by yellow arrows. Scale bar, 100 μm. g Representative immunohistochemistry (IHC) of lung tissues with SARS-CoV-2 N-specific monoclonal antibodies. Virus is indicated by yellow arrows. Scale bar, 100 μm. mRNA-RBD-H indicates the high-dose vaccine (15 μg). Data are means ± SEM (standard error of the mean). Comparisons were performed by Student’s t -test (unpaired, two tailed). Placebo animals = black circles; one injection-animals = blue triangles; two injections-vaccinated animals = red squares; dotted line = the limit of detection. Data are one representative result of two independent experiments. Source data are provided as a Source Data file.

    Article Snippet: Briefly, a monoclonal antibody specific for SARS-CoV-2 RBD protein was pre-coated onto plate wells.

    Techniques: Transgenic Assay, Mouse Assay, Histopathology, Infection, Immunohistochemistry, Two Tailed Test, Injection

    Construction and characterization of mRNA-RBD vaccine. a Schematic of the mRNA-RBD vaccine design. The SARS-CoV-2 mRNA encodes the signal peptide (SP), receptor-binding domain (RBD) from SARS-CoV-2 strain Wuhan/IVDC-HB-01/2019. b mRNA-RBD was transfected into HEK293T cells. RBD expression in the cell lysate and supernatant was analyzed by western blotting. c Particle size of LNPs by dynamic light scattering. d A representative cryo-electron microscopy image of a LNPs solution following mRNA encapsulation. Scale bar, 100 nm. e Zeta potential for LNPs at pH 4.0 and 7.4. For b and d , two independent experiments were carried out with similar results. For c and e , one representative result from three independent experiments is shown. Source data are provided as a Source Data file.

    Journal: Nature Communications

    Article Title: A single-dose mRNA vaccine provides a long-term protection for hACE2 transgenic mice from SARS-CoV-2

    doi: 10.1038/s41467-021-21037-2

    Figure Lengend Snippet: Construction and characterization of mRNA-RBD vaccine. a Schematic of the mRNA-RBD vaccine design. The SARS-CoV-2 mRNA encodes the signal peptide (SP), receptor-binding domain (RBD) from SARS-CoV-2 strain Wuhan/IVDC-HB-01/2019. b mRNA-RBD was transfected into HEK293T cells. RBD expression in the cell lysate and supernatant was analyzed by western blotting. c Particle size of LNPs by dynamic light scattering. d A representative cryo-electron microscopy image of a LNPs solution following mRNA encapsulation. Scale bar, 100 nm. e Zeta potential for LNPs at pH 4.0 and 7.4. For b and d , two independent experiments were carried out with similar results. For c and e , one representative result from three independent experiments is shown. Source data are provided as a Source Data file.

    Article Snippet: Briefly, a monoclonal antibody specific for SARS-CoV-2 RBD protein was pre-coated onto plate wells.

    Techniques: Binding Assay, Transfection, Expressing, Western Blot, Electron Microscopy