Journal: medRxiv

Article Title: Persistence of functional memory B cells recognizing SARS-CoV-2 variants despite loss of specific IgG

doi: 10.1101/2021.05.15.21257210

Figure Lengend Snippet: ( A ) PBMCs from healthy controls (HC, left) and COVID-19-patients (right) were differentiated into Ab-secreting cells. The reactivity of IgG against S1 in cell culture supernatants was determined. Each black dot represents one stimulated well. The number of stimulated wells per donor is provided directly under the x-axis. The reactivity of the serum in the same ELISA is shown with a red dot. The area between the two horizontal lines were considered to represent the borderline zone of reactivity. COVID-patients who were serum-negative for SARS-CoV-2-specific IgG (#5, #11, #12, #15) were designated COVID-19-IgG − , and those who were positive were designated COVID-19-IgG + . ( B, C ) Each symbol represents the mean IgG level of all stimulated wells for one donor. Horizontal lines indicate the mean IgG levels of all donors in the respective groups. ( B ) IgG levels of cell culture supernatants were not significantly different between the groups (one-way ANOVA, Tukey’s multiple comparison test; HC=6, COVID-19-IgG + =12, COVID-19-IgG − =4) ( C ) Both the COVID-19-IgG − and COVID-19-IgG + subgroups produced more anti-S1 IgG (one-way ANOVA, Tukey’s multiple comparison test; HC=6, COVID-19-IgG + =12, COVID-19-IgG − =4) than the HC to a similar degree. ( D, E ) The raw data for the limiting dilution experiment are shown ( D ), and the calculation is displayed ( E ). Continuous lines are shown for donors who still had SARS-CoV-2 IgGs in their serum, and the dotted lines indicate donors who lost their specific serum Abs.

Article Snippet: The total IgG and IgA levels of the culture supernatants were measured using human IgG and IgA ELISA development kits (Mabtech, Nacka Strand, Sweden).

Techniques: Cell Culture, Enzyme-linked Immunosorbent Assay, Produced