ABSTRACT. It is essential to examine the longevity of the defensive immune response engendered by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. We examined the SARS-CoV-2-specific antibody responses and ex vivo memory B-cell subsets in seven groups of individuals with COVID-19 classified based on days since reverse-transcription polymerase chain reaction confirmation of SARS-CoV-2 infection. Our data showed that the levels of IgG and neutralizing antibodies started increasing from days 15 to 30 to days 61 to 90, and plateaued thereafter. The frequencies of naive B cells and atypical memory B cells decreased from days 15 to 30 to days 61 to 90, and plateaued thereafter. In contrast, the frequencies of immature B cells, classical memory B cells, activated memory B cells, and plasma cells increased from days 15 to 30 to days 61 to 90, and plateaued thereafter. Patients with severe COVID-19 exhibited increased frequencies of naive cells, atypical memory B cells, and activated memory B cells, and lower frequencies of immature B cells, central memory B cells, and plasma cells when compared with patients with mild COVID-19. Therefore, our data suggest modifications in memory B-cell subset frequencies and persistence of humoral immunity in convalescent individuals with COVID-19.
【초록키워드】 COVID-19, neutralizing antibody, SARS-CoV-2, IgG, immune response, severe COVID-19, Neutralizing antibodies, SARS-COV-2 infection, Antibody Response, Infection, B cells, memory B cells, severe acute respiratory syndrome coronavirus-2, severe acute respiratory syndrome Coronavirus, B cell, Severe acute respiratory syndrome, polymerase chain reaction, Humoral immunity, cells, persistence, Patient, Mild, Longevity, group, Plasma cell, memory B cell, Plasma cells, Coronavirus-2, Frequency, Atypical, memory B-cell, Chain Reaction, Ex vivo, acute respiratory syndrome, frequencies, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus-2, modifications, Modification, convalescent individuals, naive cells, naïve B cells, polymerase chain, Seven, convalescent individual, classical, examined, exhibited, activated, subset, immature, central memory, individuals with COVID-19, with COVID-19, 【제목키워드】 COVID-19, B-cell,