Cremasco, VivianaWoodruff, Matthew C.Onder, LucasCupovic, JovanaNieves-Bonilla, Janice M.Schildberg, Frank A.Chang, JonathanCremasco, FlorianaHarvey, Christopher J.Wucherpfennig, KaiLudewig, BurkhardCarroll, MichaelTurley, Shannon J.2015-05-042014Cremasco, V., M. C. Woodruff, L. Onder, J. Cupovic, J. M. Nieves-Bonilla, F. A. Schildberg, J. Chang, et al. 2014. “B cell homeostasis and follicle confines are governed by fibroblastic reticular cells.” Nature immunology 15 (10): 973-981. doi:10.1038/ni.2965. http://dx.doi.org/10.1038/ni.2965.1529-2908http://nrs.harvard.edu/urn-3:HUL.InstRepos:15034756Fibroblastic reticular cells (FRCs) are known to inhabit T cell-rich areas of lymphoid organs where they function to coordinate T cell and dendritic cell interactions. However, in vivo manipulation of FRCs has been limited by a dearth of genetic tools targeting this lineage. Here, using a mouse model to conditionally ablate FRCs, we demonstrate their indispensable role in anti-viral T cell responses. Unexpectedly, FRC loss also attenuated humoral immunity due to impaired B cell viability and follicular organization. Follicle-resident FRCs established a favorable niche for B lymphocytes via production of the cytokine BAFF. Thus, our study indicates that adaptive immunity requires an intact FRC network and illuminates a subset of FRCs that controls B cell homeostasis and follicle identity.en-USJournal Article2015-05-0410.1038/ni.2965