A Molecular Analysis of Memory B Cell and Antibody Responses Against Merozoite Surface Protein 1 in Children and Adults From Uganda.

Memory B cells (MBCs) and plasma antibodies against () merozoite antigens are important components of the protective immune response against malaria. To gain understanding of how responses against develop in these two arms of the humoral immune system, we evaluated MBC and antibody responses against the most abundant merozoite antigen, full-length merozoite surface protein 1 (PfMSP1), in individuals from a region in Uganda with high transmission. Our results showed that PfMSP1-specific B cells in adults with immunological protection against malaria were predominantly IgG classical MBCs, while children with incomplete protection mainly harbored IgM PfMSP1-specific classical MBCs.

SARS-CoV-2 spike-specific memory B cells express higher levels of T-bet and FcRL5 after non-severe COVID-19 as compared to severe disease.

SARS-CoV-2 infection elicits a robust B cell response, resulting in the generation of long-lived plasma cells and memory B cells. Here, we aimed to determine the effect of COVID-19 severity on the memory B cell response and characterize changes in the memory B cell compartment between recovery and five months post-symptom onset. Using high-parameter spectral flow cytometry, we analyzed the phenotype of memory B cells with reactivity against the SARS-CoV-2 spike protein or the spike receptor binding domain (RBD) in recovered individuals who had been hospitalized with non-severe (n = 8) or severe (n = 5) COVID-19.

SARS-CoV-2 spike-specific memory B cells express markers of durable immunity after non-severe COVID-19 but not after severe disease.

SARS-CoV-2 infection elicits a robust B cell response, resulting in the generation of long-lived plasma cells and memory B cells. Here, we aimed to determine the effect of COVID-19 severity on the memory B cell response and characterize changes in the memory B cell compartment between recovery and five months post-symptom onset. Using high-parameter spectral flow cytometry, we analyzed the phenotype of memory B cells with reactivity against the SARS-CoV-2 spike protein or the spike receptor binding domain (RBD) in recovered individuals who had been hospitalized with non-severe (n=8) or severe (n=5) COVID-19.