Artem Mikelov, Evgeniia Alekseeva, Dmitry Chudakov and Georgii Bazykin from Skoltechco-authored a preprint “Memory persistence and differentiation into antibody-secreting cells accompanied by positive selection in longitudinal BCR repertoires” that was released at bioRxiv. The study is focused on B cell response. The researchers analyzed the dynamics of immunoglobulin heavy chain (IGH) repertoires of memory B cells, plasmablasts and plasma cells sampled several times during one year from peripheral blood of volunteers without severe inflammatory diseases. Based on these data, they revealed a high degree of clonal persistence in individual memory B-cell subsets with inter-individual convergence in memory and antibody-secreting cells (ASCs). Phylogenetic analysis revealed signs of reactivation of persisting memory B cell-enriched clonal lineages, accompanied by new rounds of affinity maturation during proliferation to ASCs. Clonotypes of ASCs demonstrated clonal relatedness to memory B cells and are transient in peripheral blood. The authors of the study concluded that negative selection contributes to both persisting and reactivated lineages of B cells, saving functionality and specificity of BCRs to protect from the current and future pathogens. Full text of the preprint is available here.