Shared transcriptional profiles at the single cell level of atypical memory B cells suggest common drivers of expansion and function in malaria, HIV and autoimmune diseases [Malaria VDJ+GEX scRNA-seq]

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 scRNA seq (VDJ+GEX) of peripheral blood B cells isolated by negative selection from two adults living in malaria-endemic Mali The raw data is to be made available through dbGaP (controlled access)