Single-dose intranasal administration of AdCOVID elicits systemic and mucosal immunity against SARS-CoV-2 in mice

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Abstract

The coronavirus disease 2019 (COVID-19) pandemic has highlighted the urgent need for effective preventive vaccination to reduce burden and spread of severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) in humans. Intranasal vaccination is an attractive strategy to prevent COVID-19 as the nasal mucosa represents the first-line barrier to SARS-CoV-2 entry before viral spread to the lung. Although SARS-CoV-2 vaccine development is rapidly progressing, the current intramuscular vaccines are designed to elicit systemic immunity without conferring mucosal immunity. Here, we show that AdCOVID, an intranasal adenovirus type 5 (Ad5)-vectored vaccine encoding the receptor binding domain (RBD) of the SARS-CoV-2 spike protein, elicits a strong and focused immune response against RBD through the induction of mucosal IgA, serum neutralizing antibodies and CD4 + and CD8 + T cells with a Th1-like cytokine expression profile. Therefore, AdCOVID, which promotes concomitant systemic and local mucosal immunity, represents a promising COVID-19 vaccine candidate.

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  1. SciScore for 10.1101/2020.10.10.331348: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementIACUC: Studies performed at UAB were performed under IACUC Approval Number 21203.
    RandomizationVaccination: Inbred female C57BL/6J (The Jackson Laboratory) and outbred CD-1 (Charles River Laboratories) mice of at least 6 weeks of age were randomly allocated into vaccination groups.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variableVaccination: Inbred female C57BL/6J (The Jackson Laboratory) and outbred CD-1 (Charles River Laboratories) mice of at least 6 weeks of age were randomly allocated into vaccination groups.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    After removal of the mouse anti-adenovirus-5 hexon antibody and additional phosphate-buffered saline washes,
    anti-adenovirus-5
    suggested: None
    HRP-conjugated rat anti-mouse antibody was added to each well and incubated at least 60 minutes at 37°C.
    anti-mouse
    suggested: None
    The loading of recombinant SARS2-CoV-2 spike onto the beads was evaluated by staining 1E+05 beads with dilutions ranging from 1μg to 2ng/ml of the recombinant anti-SARS spike antibody CR3022 and visualized with an anti-human IgG secondary antibody.
    anti-SARS
    suggested: None
    anti-human IgG
    suggested: None
    Briefly, 0.2 mg of goat polyclonal anti-mouse IgG (southern Biotech cat# 1013-01), anti-IgM (cat#1 022-01), and anti-IgA (cat# 1040-01) antibodies in PBS were mixed with 5E+07 fluorescent microparticles each with a unique fluorescent intensity in the far red channels (Spherotech 3.6um cat# CPAK-3567-4K, peaks 1-3) resuspended in 0.1 M MES buffer pH 5.0.
    anti-mouse IgG
    suggested: (SouthernBiotech Cat# 1013-01, RRID:AB_2794188)
    anti-IgM
    suggested: None
    anti-IgA
    suggested: None
    For primary antibody detection, a SARS-CoV-2 spike/RBD antibody (Rabbit, Polyclonal, SinoBiologicals Ct No. 40592-T62) was added to 5% Blotto and incubated on the monolayers overnight.
    spike/RBD
    suggested: None
    Samples were incubated for 10 minutes at 4°C in the dark with Fc-Block (clone 24G2, 10 μg/ml), washed with 200 µl staining media (SME) and then stained with myeloid, B cell or BAL antibody panels.
    BAL
    suggested: None
    Cells were then incubated on ice with a combination of fluorescent dye-labelled antibodies including anti-CD4-V500 (clone GK1.5; 1:200 dilution), anti-CD8α-APC-Fire750 (clone 53-6.7; 1:200 dilution), anti-CD11a/CD18-Pacific Blue (H155-78; 1:200 dilution), anti-CD103-PE (M290; 1:200 dilution), anti-CD69-FITC (H1-2F3; 1:200 dilution), anti-Ly6G-PerCP-Cy5.5 (clone 1A8; 1:200 dilution), anti-CD64-PerCP-Cy5.5 (clone X54-5/7.1; 1:200 dilution), anti-B220/CD45R-PerCP (clone RA3-6B2; 1:200 dilution), and Red LIVE/DEAD (1:1000 dilution).
    anti-CD4-V500
    suggested: None
    anti-CD8α-APC-Fire750
    suggested: None
    anti-CD11a/CD18-Pacific
    suggested: None
    anti-CD103-PE
    suggested: None
    M290
    suggested: None
    anti-CD69-FITC
    suggested: (Sigma-Aldrich Cat# SAB4700221, RRID:AB_10898330)
    anti-Ly6G-PerCP-Cy5.5
    suggested: None
    anti-CD64-PerCP-Cy5.5
    suggested: None
    anti-B220/CD45R-PerCP
    suggested: None
    Experimental Models: Cell Lines
    SentencesResources
    Adenovirus vaccine titer measurement: 293 HEK cells were seeded in a 96-well plate one day before Ad vector infection.
    HEK
    suggested: None
    Vero E6 cells were grown on 96-well plates to confluence.
    Vero E6
    suggested: None
    After incubation, the sera:virus mixtures were added to the wells (100µL), and infection allowed to proceed for 1 hour on the Vero cells at 35°C.
    Vero
    suggested: None
    Experimental Models: Organisms/Strains
    SentencesResources
    CD-1).
    CD-1
    suggested: RRID:MGI:2686808)
    Dose levels used included high-dose (3.35E+08 ifu), mid-dose (6E+07 ifu) or low-dose (6E+06 ifu) of vaccine except for the S1 vector tested C57BL/6J mice were the high dose vaccine was 6E+08 ifu.
    C57BL/6J
    suggested: None
    Software and Algorithms
    SentencesResources
    Ethics statement and Mice: Mice used in these studies were obtained from the Jackson Laboratory (C56BL/6J) or Charles River Laboratories (
    Charles River Laboratories
    suggested: (Charles River Laboratories, RRID:SCR_003792)
    Following acquisition, the resulting FCS files were analyzed in flowJo (treestar).
    flowJo
    suggested: (FlowJo, RRID:SCR_008520)
    Plates were washed 5X with PBS, and further incubated with a goat anti-rabbit IgG conjugated to horseradish peroxidase (Boster Biological Technology Co., #BA1054-0.5) in 5% Blotto for 1 hr.
    Boster Biological
    suggested: None
    Quantification and statistical analysis: Statistical significance was assigned when P values were < 0.05 using Prism Version 8.4.2 (GraphPad).
    Prism
    suggested: (PRISM, RRID:SCR_005375)
    GraphPad
    suggested: (GraphPad Prism, RRID:SCR_002798)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).


    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.


    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.


    Results from JetFighter: We did not find any issues relating to colormaps.


    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

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