Human memory B cells show plasticity and adopt multiple fates upon recall response to SARS-CoV-2

Boyman and colleagues perform phenotypic and B cell receptor sequencing analysis of memory B cell subsets in severe acute respiratory syndrome coronavirus 2-infected and subsequently vaccinated individuals up to 1 year post-infection to show that single memory B cell clones can adopt different trajectories. The B cell response to different pathogens uses tailored effector mechanisms and results in functionally specialized memory B (B-m) cell subsets, including CD21(+) resting, CD21(-)CD27(+) activated and CD21(-)CD27(-) B-m cells. The interrelatedness between these B-m cell subsets remains unknown. Here we showed that single severe acute respiratory syndrome coronavirus 2-specific B-m cell clones showed plasticity upon antigen rechallenge in previously exposed individuals. CD21(-) B-m cells were the predominant subsets during acute infection and early after severe acute respiratory syndrome coronavirus 2-specific immunization. At months 6 and 12 post-infection, CD21(+) resting B-m cells were the major B-m cell subset in the circulation and were also detected in peripheral lymphoid organs, where they carried tissue residency markers. Tracking of individual B cell clones by B cell receptor sequencing revealed that previously fated B-m cell clones could redifferentiate upon antigen rechallenge into other B-m cell subsets, including CD21(-)CD27(-) B-m cells, demonstrating that single B-m cell clones can adopt functionally different trajectories.

Automated summary

Boyman and colleagues conducted a study on memory B cell subsets in individuals infected with and vaccinated against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). They found that single memory B cell clones can adopt different trajectories. Different pathogens elicit tailored effector mechanisms and result in functionally specialized memory B cell subsets. The study showed that previously exposed individuals exhibited plasticity in SARS-CoV-2-specific memory B cell clones upon antigen rechallenge.