Perdiguero, PedroMartín-Martín, AlbaBenedicenti, OttaviaDíaz-Rosales, PatriciaMorel, EstherMuñoz-Atienza, EstefaníaGarcía-Flores, MónicaSimón, RocíoSoleto, IreneCerutti, Andrea, 1965-Tafalla, Carolina2021-03-242021-03-242019Perdiguero P, Martín-Martín A, Benedicenti O, Díaz-Rosales P, Morel E, Muñoz-Atienza E, et al. Teleost IgD + IgM - B cells mount clonally expanded and mildly mutated intestinal IgD responses in the absence of lymphoid follicles. Cell Rep. 2019 Dec 24; 29(13): 4223-35.e5. DOI: 10.1016/j.celrep.2019.11.1012211-1247http://hdl.handle.net/10230/46914Immunoglobulin D (IgD) is an ancient antibody with dual membrane-bound and fluid-phase antigen receptor functions. The biology of secreted IgD remains elusive. Here, we demonstrate that teleost IgD+IgM- plasmablasts constitute a major lymphocyte population in some mucosal surfaces, including the gut mucosa. Remarkably, secreted IgD binds to gut commensal bacteria, which in turn stimulate IgD gene transcription in gut B cells. Accordingly, secreted IgD from gut as well as gill mucosae, but not the spleen, show a V(D)J gene configuration consistent with microbiota-driven clonal expansion and diversification, including mild somatic hypermutation. By showing that secreted IgD establishes a mutualistic relationship with commensals, our findings suggest that secreted IgD may play an evolutionary conserved role in mucosal homeostasis.application/pdfengCopyright © 2019 The Author(s). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).info:eu-repo/semantics/articlehttp://dx.doi.org/10.1016/j.celrep.2019.11.101B cellsIgDSHMClonal expansionGillsIntestineMicrobiotaSomatic hypermutationTeleost fishinfo:eu-repo/semantics/openAccess