Background Neutralizing-antibody (nAb) is the major focus of most ongoing COVID-19 vaccine trials. However, nAb response against SARS-CoV-2, when present, decays rapidly. Given the myriad roles of antibodies in immune responses, it is possible that antibodies could also mediate protection against SARS-CoV-2 via effector mechanisms such as antibody-dependent cellular cytotoxicity (ADCC), which we sought to explore here. Methods Plasma of 3 uninfected controls and 20 subjects exposed to, or recovering from, SARS-CoV-2 infection were collected from U.S. and sub-Saharan Africa. Immunofluorescence assay was used to detect the presence of SARS-CoV-2 specific IgG antibodies in the plasma samples. SARS-CoV-2 specific neutralizing capability of these plasmas was assessed with SARS-CoV-2 spike pseudotyped virus. ADCC activity was assessed with a calcein release assay. Results SARS-CoV-2 specific IgG antibodies were detected in all COVID-19 subjects studied. All but three COVID-19 subjects contained nAb at high potency (>80% neutralization). Plasma from 19/20 of COVID-19 subjects also demonstrated strong ADCC activity against SARS-CoV-2 spike glycoprotein, including two individuals without nAb against SARS-CoV-2. Conclusion Both neutralizing and non-neutralizing COVID-19 plasmas can mediate ADCC. Our findings argue that evaluation of potential vaccines against SARS-CoV-2 should include investigation of the magnitude and durability of ADCC, in addition to nAb.
【초록키워드】 COVID-19, SARS-CoV-2, Vaccine, antibody, neutralization, SARS-COV-2 infection, spike glycoprotein, Pseudotyped virus, IgG antibodies, SARS-CoV-2 spike glycoprotein, sub-Saharan Africa, immunofluorescence assay, immune responses, plasma, Neutralizing, ADCC, antibody-dependent cellular cytotoxicity, NAb, SARS-CoV-2 spike, focus, high potency, subject, individual, ADCC activity, calcein, COVID-19 vaccine trials, effector mechanisms, nAb response, Neutralizing-antibody, plasma samples, plasmas, specific IgG antibodies, Effector mechanism, Result, was used, detect, collected, include, addition, demonstrated, magnitude, uninfected control, specific IgG antibody, 【제목키워드】 COVID-19, SARS-CoV-2, Presence,