Journal: PLOS ONE

Article Title: Discovery of anti-SARS-CoV-2 S2 protein antibody CV804 with broad-spectrum reactivity with various beta coronaviruses and analysis of its pharmacological properties in vitro and in vivo

doi: 10.1371/journal.pone.0300297

Figure Lengend Snippet: (A) Five humanized CV804 antibodies were analyzed by flow cytometric assay of titrated candidates against SARS-CoV-2 spike protein expressing cells. Four parameter logistic curve fitted with EC 50 in parentheses. Normalized by secondary alone and saturation signal. Representative data of two independent experiments are shown. (B) Evaluation of hCV804-40 antibody, REGN10987, and LY-CoV1404 antibody binding to cells infected with SARS-CoV-2 variants. "+++", "++", "+" indicate positive binding; "-" indicates negative binding. (C) Evaluation of antibody-dependent cell-mediated cytotoxicity ADCC activity against spike-expressing cells for mouse derived antibodies. (D) In vitro cell infection inhibition experiments were conducted. The viral strains used were hCoV-19/Japan/TY/WK-521/2020 (top) and SARS-CoV-2/Japan/TY-501/2020 (bottom), with VeroE6/TMPRSS2 cells being used as the target cells. The hCV804-35 antibody, REGN10987, and LY-CoV 1404 were measured in this experiment. The antibody concentration that inhibited cell death by 50% was defined as the IC 50 .

Article Snippet: ADCC activity was measured by mouse FcγRIV ADCC Reporter Bioassay kit (Promega) according to manufacturer’s instruction.

Techniques: Flow Cytometry, Expressing, Binding Assay, Infection, Activity Assay, Derivative Assay, In Vitro, Inhibition, Concentration Assay