Composition of B cell subsets in convalescent COVID-19 patients and healthy controls
SARS-CoV-2 specific B cell response was analysed in COVID-19 patients and healthy donors by characterizing levels of IgD-CD27+ BMEMORY, IgD+CD27+ unswitched BMEMORY, IgD+ CD27- BNAIVE,and CD27++ CD38++ plasmablasts (gating strategy shown in Figure 2).
Overall frequencies for all B cell subsets were similar between convalescent COVID-19 patients and healthy donors. IgD+ CD27- BNAIVEcells represented most B cells at around 50% of the population, while IgD- CD27+ BMEMORYcells and IgD+ CD27+ unswitched BMEMORY cells demonstrated levels ranging between 15 – 20 % of the entire B cell population. CD27++CD38++ plasmablasts constituted on average less than 1 % of the B cells (Figure 3a).