Project description:Purpose: We wanted to explore further heterogeneity of MBC subsets that were previously defined by our lab. Methods: MBC subsets were sorted and stained with unique anti-mouse HTO antibodies (CITE-seq). Results: We found that heterogeneity among MBC subsets was most prominent among DP MBC subsets, which could be separated by extrafollicular or germinal center transcriptional signatures, whereas DN and SP MBCs mostly exhibited an extrafollicular signature.
Project description:Human chronic infectious diseases have been shown to alter the composition and phenotype of the B cell compartment, which, in part, can attribute to failure to acquire protective immunity. However, the extent of such alterations is poorly understood. Here, using a combination of bulk and single cell RNA-sequencing (scRNA-seq) of B cells in individuals living in malaria-endemic Africa, we characterized changes in naïve B cell, classical memory B cell (MBC) and atypical MBC subsets. Of particular interest were unswitched atypical MBCs that expanded in children upon the onset of febrile malaria. This subpopulation expressed IgD but only low levels of IgM (IgD+IgMlo), high levels of the atypical MBC markers, Tbet and CD11c, as well as the intrinsically autoreactive VH4-34. IgD+IgMlo atypical MBCs were distinguished functionally by their acquisition of high antigen-affinity thresholds for activation, suggesting the IgD+IgMlo atypical MBC expansion during febrile malaria may reduce responses to low affinity self-antigens during acute malaria