Germinal center expansion but not plasmablast differentiation is proportional to peptide-MHCII density via CD40-CD40L signaling strength.

ABSTRACT: T follicular helper (TFH) cells promote expansion of germinal center (GC) B cells and plasma cell differentiation. Whether cognate peptide-MHCII (pMHCII) density instructs selection and cell fate decisions in a quantitative manner remains unclear. Using αDEC205-OVA to differentially deliver OVA peptides to GC B cells on the basis of DEC205 allelic copy number, we find DEC205^+/+ B cells take up 2-fold more antigen than DEC205^+/- cells, leading to proportional TFH cell help and B cell expansion. To validate these results, we establish a caged OVA peptide, which is readily detected by OVA-specific TFH cells after photo-uncaging. In situ uncaging of peptides leads to multiple serial B-T contacts and cell activation. Differential CD40 signaling, is both necessary and suffi

SUBMITTER: Jing Z 

PROVIDER: S-EPMC9178878 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature