Protective fibroblastic niches in secondary lymphoid organs

Lymphoid organ fibroblasts, known as fibroblastic reticular cells (FRCs), generate specialized niches in the tissue and coordinate immune cell interactions. De Martin and colleagues discuss basic concepts of FRC biology and how FRCs determine activation or attenuation of immune responses. Fibroblastic reticular cells (FRCs) are specialized fibroblasts of secondary lymphoid organs that provide the structural foundation of the tissue. Moreover, FRCs guide immune cells to dedicated microenvironmental niches where they provide lymphocytes and myeloid cells with homeostatic growth and differentiation factors. Inflammatory processes, including infection with pathogens, induce rapid morphological and functional adaptations that are critical for the priming and regulation of protective immune responses. However, adverse FRC reprogramming can promote immunopathological tissue damage during infection and autoimmune conditions and subvert antitumor immune responses. Here, we review recent findings on molecular pathways that regulate FRC-immune cell crosstalk in specialized niches during the generation of protective immune responses in the course of pathogen encounters. In addition, we discuss how FRCs integrate immune cell-derived signals to ensure protective immunity during infection and how therapies for inflammatory diseases and cancer can be developed through improved understanding of FRC-immune cell interactions.

Automated summary

This article discusses the biology of fibroblastic reticular cells (FRCs) in lymphoid organs and their role in activating or attenuating immune responses. FRCs provide structural support in secondary lymphoid organs and guide immune cells to specialized microenvironments. Adverse reprogramming of FRCs can lead to immunopathological tissue damage during infection and autoimmune conditions, as well as subvert antitumor immune responses.