Open AccessRegulation of the Bone Marrow Niche by Inflammation
Author(s) -
Ioannis Mitroulis,
Lydia Kalafati,
Martin Bornhäuser,
George Hajishengallis,
Triantafyllos Chavakis
Publication year - 2020
Publication title -
frontiers in immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 124
ISSN - 1664-3224
DOI - 10.3389/fimmu.2020.01540
Subject(s) - myelopoiesis , microbiology and biotechnology , haematopoiesis , inflammation , biology , niche , bone marrow , crosstalk , paracrine signalling , stem cell , immunology , hematopoietic stem cell , genetics , ecology , physics , receptor , optics
Hematopoietic stem cells (HSC) reside in the bone marrow (BM) within a specialized micro-environment, the HSC niche, which comprises several cellular constituents. These include cells of mesenchymal origin, endothelial cells and HSC progeny, such as megakaryocytes and macrophages. The BM niche and its cell populations ensure the functional preservation of HSCs. During infection or systemic inflammation, HSCs adapt to and respond directly to inflammatory stimuli, such as pathogen-derived signals and elicited cytokines, in a process termed emergency myelopoiesis, which includes HSC activation, expansion, and enhanced myeloid differentiation. The cell populations of the niche participate in the regulation of emergency myelopoiesis, in part through secretion of paracrine factors in response to pro-inflammatory stimuli, thereby indirectly affecting HSC function. Here, we review the crosstalk between HSCs and cell populations in the BM niche, specifically focusing on the adaptation of the HSC niche to inflammation and how this inflammatory adaptation may, in turn, regulate emergency myelopoiesis.