Affinity maturation and B cell differentiation in the germinal center after Plasmodium immunization скачать в хорошем качестве

Affinity maturation and B cell differentiation in the germinal center after Plasmodium immunization

2025 Immcantation Users Group Meeting https://immcantation.github.io/users-... Title: Linking affinity maturation and B cell differentiation in the germinal center after Plasmodium immunization Speaker: Prof. Ian Cockburn, The Australian National University Abstract: Long-lived plasma cells (PCs) secrete antibodies that can provide sustained immunity against infection. It has been proposed that high affinity cells are preferentially selected into this compartment, potentiating the immune response. We used single cell RNA-seq to track the germinal center (GC) development of Ighg2A10 cells, specific for the Plasmodium falciparum circumsporozoite protein (PfCSP). Following immunization with Plasmodium sporozoites we identified 3 populations of cells in the GC light zone. One population expressed a gene signature associated with the initiation of PC differentiation and had an enhanced propensity to form PCs in vitro. Unexpectedly, the estimated affinity of this putative pre-PC population was indistinguishable from cells in the GC generally. This was also true when high- or low-avidity recombinant PfCSP proteins were used as immunogens. Immunization with low-avidity PfCSP did, however, induce increased affinity maturation. Collectively these findings suggest that the initiation of PC development in the GC occurs via an affinity independent process.