A splenic IgM memory subset with antibacterial specificities is sustained from persistent mucosal responses.

ABSTRACT: To what extent immune responses against the gut flora are compartmentalized within mucosal tissues in homeostatic conditions remains a much-debated issue. We describe here, based on an inducible AID fate-mapping mouse model, that systemic memory B cell subsets, including mainly IgM⁺ B cells in spleen, together with IgA⁺ plasma cells in spleen and bone marrow, are generated in mice in the absence of deliberate immunization. While the IgA component appears dependent on the gut flora, IgM memory B cells are still generated in germ-free mice, albeit to a reduced extent. Clonal relationships and renewal kinetics after anti-CD20 treatment reveal that this long-lasting splenic population is mainly sustained by output of B cell clones persisting in mucosal germinal centers. I

SUBMITTER: Le Gallou S 

PROVIDER: S-EPMC6080908 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature