title: Two Niches in the Bone Marrow: A Hypothesis on Life-long T Cell Memory.
abstract: The concept is emerging that the bone marrow (BM) sustains life-long persistence of memory T cells, as it does for plasma cells. Recent studies revived the debate on how this is achieved: is the BM essentially a nest for the proliferation of recirculating memory T cells, or a storage depot for resting memory T cells? Learning from division of labor in hematopoietic stem cells, this article proposes that two distinct BM niches support memory T cell cycling and quiescence, thereby enabling memory T cells to maintain all their distinguishing features. This framework might be instrumental to interpret some puzzling findings and conceptualize the mechanisms preserving either stability of memory T cell numbers or the capacity to mount secondary responses.
authors.affiliation: Institute of Molecular Biology and Pathology, Consiglio Nazionale delle Ricerche, Rome, Italy. Electronic address: francesca.dirosa@uniroma1.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: Di Rosa
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000502:physiology*; D001854:Bone Marrow Cells / Q000166:cytology* / Q000502:physiology*; D002454:Cell Differentiation; D049109:Cell Proliferation; D060833:Cellular Microenvironment; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology; D006706:Homeostasis; D006801:Humans; D007156:Immunologic Memory; D015398:Signal Transduction; D055153:Stem Cell Niche; D013601:T-Lymphocytes / Q000166:cytology* / Q000502:physiology*
keywords: bone marrow; homeostatic proliferation; memory T cells