About InVivoMAb anti-SARS-CoV-2 S protein (RBD epitope B) The SARS2-34 monoclonal antibody reacts with the receptor binding domain (RBD) in the spike (S) protein of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2). SARS-CoV-2 is a positive-sense, single-stranded RNA virus which causes the acute respiratory disease COVID-19. The S protein is the main surface antigen of SARS-CoV-2. The RBD in the S protein specifically binds to angiotensin-converting enzyme 2 (ACE2) on target cells, mediating SARS-CoV-2 host cell entry. The SARS2-34 antibody has been shown to block the binding of the SARS-CoV-2 S protein to ACE2 in vitro. InVivoMAb anti-SARS-CoV-2 S protein (RBD epitope B) Specifications IsotypeMouse IgG1, κ Recommended Isotype Control(s)InVivoMAb mouse IgG1 isotype control, unknown specificity Recommended Dilution BufferInVivoPure pH 7.0 Dilution Buffer ImmunogenSARS-CoV-2 S and RBD proteins Reported Applicationsin vitro blocking of SARS-CoV-2 S protein Flow cytometry ELISA FormulationPBS, pH 7.0 Contains no stabilizers or preservatives Endotoxin<2EU/mg (<0.002EU/μg) Determined by LAL gel clotting assay Purity>95% Determined by SDS-PAGE Sterility0.2 μm filtration ProductionPurified from cell culture supernatant in an animal-free facility PurificationProtein G RRIDAB_2894778 Molecular Weight150 kDa StorageThe antibody solution should be stored at the stock concentration at 4°C. Do not freeze. Application ReferencesInVivoMAb anti-SARS-CoV-2 S protein (RBD epitope B) (CLONE: SARS2-34)VanBlargan, L., et al (2021). "A potently neutralizing anti-SARS-CoV-2 antibody inhibits variants of concern by binding a highly conserved epitope" bioRxiv . PubMedWith the emergence of SARS-CoV-2 variants with increased transmissibility and potential resistance, antibodies and vaccines with broadly inhibitory activity are needed. Here we developed a panel of neutralizing anti-SARS-CoV-2 mAbs that bind the receptor binding domain of the spike protein at distinct epitopes and block virus attachment to cells and its receptor, human angiotensin converting enzyme-2 (hACE2). While several potently neutralizing mAbs protected K18-hACE2 transgenic mice against infection caused by historical SARS-CoV-2 strains, others induced escape variants in vivo and lost activity against emerging strains. We identified one mAb, SARS2-38, that potently neutralizes all SARS-CoV-2 variants of concern tested and protects mice against challenge by multiple SARS-CoV-2 strains. Structural analysis showed that SARS2-38 engages a conserved epitope proximal to the receptor binding motif. Thus, treatment with or induction of inhibitory antibodies that bind conserved spike epitopes may limit the loss of potency of therapies or vaccines against emerging SARS-CoV-2 variants.Liu, Z., et al (2021). "Identification of SARS-CoV-2 spike mutations that attenuate monoclonal and serum antibody neutralization" Cell Host Microbe 29(3): 477-488 e474. PubMedNeutralizing antibodies against the SARS-CoV-2 spike (S) protein are a goal of COVID-19 vaccines and have received emergency use authorization as therapeutics. However, viral escape mutants could compromise efficacy. To define immune-selected mutations in the S protein, we exposed a VSV-eGFP-SARS-CoV-2-S chimeric virus, in which the VSV glycoprotein is replaced with the S protein, to 19 neutralizing monoclonal antibodies (mAbs) against the receptor-binding domain (RBD) and generated 50 different escape mutants. Each mAb had a unique resistance profile, although many shared residues within an epitope of the RBD. Some variants (e.g., S477N) were resistant to neutralization by multiple mAbs, whereas others (e.g., E484K) escaped neutralization by convalescent sera. Additionally, sequential selection identified mutants that escape neutralization by antibody cocktails. Comparing these antibody-mediated mutations with sequence variation in circulating SARS-CoV-2 revealed substitutions that may attenuate neutralizing immune responses in some humans and thus warrant further investigation.Hassan, A. O., et al (2020). "A Single-Dose Intranasal ChAd Vaccine Protects Upper and Lower Respiratory Tracts against SARS-CoV-2" Cell 183(1): 169-184 e113. PubMedThe coronavirus disease 2019 pandemic has made deployment of an effective vaccine a global health priority. We evaluated the protective activity of a chimpanzee adenovirus-vectored vaccine encoding a prefusion stabilized spike protein (ChAd-SARS-CoV-2-S) in challenge studies with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and mice expressing the human angiotensin-converting enzyme 2 receptor. Intramuscular dosing of ChAd-SARS-CoV-2-S induces robust systemic humoral and cell-mediated immune responses and protects against lung infection, inflammation, and pathology but does not confer sterilizing immunity, as evidenced by detection of viral RNA and induction of anti-nucleoprotein antibodies after SARS-CoV-2 challenge. In contrast, a single intranasal dose of ChAd-SARS-CoV-2-S induces high levels of neutralizing antibodies, promotes systemic and mucosal immunoglobulin A (IgA) and T cell responses, and almost entirely prevents SARS-CoV-2 infection in both the upper and lower respiratory tracts. Intranasal administration of ChAd-SARS-CoV-2-S is a candidate for preventing SARS-CoV-2 infection and transmission and curtailing pandemic spread.
