Abstract
COVID-19 pandemic poses a serious threat to human health; it has completely disrupted global stability, making vaccine development an important goal to achieve. Monoclonal antibodies play an important role in subunit vaccines strategies. In this work, nine murine MAbs against the RBD of the SARS-CoV-2 spike protein were obtained by hybridoma technology. Characterization of purified antibodies demonstrated that five of them have affinities in the order of 10 8 L/mol. Six MAbs showed specific recognition of different recombinant RBD-S antigens in solution. Studies of the additivity index of anti-RBD antibodies, by using a novel procedure to determine the additivity cut point, showed recognition of at least five different epitopes. The MAbs CBSSRBD-S.11 and CBSSRBD-S.8 revealed significant neutralizing capacity against SARS-CoV-2 in an ACE2-RBD binding inhibition assay (IC 50 = 85.5pM and IC 50 = 122.7pM, respectively) and in a virus neutralizing test with intact SARS-CoV-2 (VN 50 = 0.552 nM and VN 50 = 4.854 nM, respectively) when D614G strain was used to infect Vero cells. Also CBSSRBD-S.11 neutralized the SARS-CoV-2 strains Alpha and Beta: VN 50 = 0.707 nM and VN 50 = 0.132 nM, respectively. The high affinity CBSSRBD-S.8 and CBSSRBD-S.7 recognized different epitopes, so they are suitable for the development of a sandwich ELISA to quantitate RBD-S recombinant antigens in biomanufacturing processes, as well as in pharmacokinetic studies in clinical and preclinical trials.
Keywords: Additivity index; COVID-19; Neutralizing monoclonal antibodies; Receptor binding domain; SARS-CoV-2.
【저자키워드】 COVID-19, SARS-CoV-2, Receptor binding domain, breath, neutralizing monoclonal antibodies, Additivity index, 【초록키워드】 SARS-CoV-2, Vaccine development, pandemic, antibody, monoclonal antibodies, virus, Spike protein, Receptor binding domain, Antigen, Epitopes, stability, recombinant antigens, SARS-CoV-2 spike protein, D614G, Alpha, Beta, Subunit vaccine, Neutralizing, neutralizing capacity, trials, sandwich ELISA, mAbs, neutralizing monoclonal antibodies, affinity, monoclonal, binding, pharmacokinetic, subunit vaccines, strain, characterization, Recognition, hybridoma technology, solution, high affinity, ACE2-RBD binding, Anti-RBD antibodies, Vero cells, infect, murine, FIVE, affinities, neutralized, was used, nine, determine, demonstrated, the RBD, purified, the SARS-CoV-2, 【제목키워드】 Vaccine development, clinical trial, monoclonal antibody, RBD, subunit, the SARS-CoV-2,