Dendritic cells shape and sustain fibroblast niches.

Fibroblasts are highly attuned for immune crosstalk within lymphoid tissues. In this issue of Immunity, Alouche et al. provide insight into how fibroblast immunoregulatory phenotypes are acquired and maintained, revealing that Ccl19hi fibroblastic reticular cells require continuous signaling via Notch2. Dendritic cells produce Notch ligands to promote CCL19-rich stromal niches, which cluster CD8+ T cells centrally in lymph nodes.