Activated Peyer's patch B cells sample antigen directly from M cells in the subepithelial dome.

ABSTRACT: The germinal center (GC) reaction in Peyer's patches (PP) requires continuous access to antigens, but how this is achieved is not known. Here we show that activated antigen-specific CCR6⁺CCR1⁺GL7^- B cells make close contact with M cells in the subepithelial dome (SED). Using in situ photoactivation analysis of antigen-specific SED B cells, we find migration of cells towards the GC. Following antigen injection into ligated intestinal loops containing PPs, 40% of antigen-specific SED B cells bind antigen within 2?h, whereas unspecifc cells do not, indicating B cell-receptor involvment. Antigen-loading is not observed in M cell-deficient mice, but is unperturbed in mice depleted of classical dendritic cells (DC). Thus, we report a M cell-B cell antigen-specific transporting pathway in PP that is independent of DC. We propose that this antigen transporting pathway has a critical role in gut IgA responses, and should be taken into account when developing mucosal vaccines.

SUBMITTER: Komban RJ 

PROVIDER: S-EPMC6547658 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature