CXCR1 remodels the vascular niche to promote hematopoietic stem and progenitor cell engraftment

BW Blaser, JL Moore, EJ Hagedorn, B Li… - Journal of Experimental …, 2017 - rupress.org
BW Blaser, JL Moore, EJ Hagedorn, B Li, R Riquelme, A Lichtig, S Yang, Y Zhou
Journal of Experimental Medicine, 2017rupress.org
The microenvironment is an important regulator of hematopoietic stem and progenitor cell
(HSPC) biology. Recent advances marking fluorescent HSPCs have allowed exquisite
visualization of HSPCs in the caudal hematopoietic tissue (CHT) of the developing
zebrafish. Here, we show that the chemokine cxcl8 and its receptor, cxcr1, are expressed by
zebrafish endothelial cells, and we identify cxcl8/cxcr1 signaling as a positive regulator of
HSPC colonization. Single-cell tracking experiments demonstrated that this is a result of …
The microenvironment is an important regulator of hematopoietic stem and progenitor cell (HSPC) biology. Recent advances marking fluorescent HSPCs have allowed exquisite visualization of HSPCs in the caudal hematopoietic tissue (CHT) of the developing zebrafish. Here, we show that the chemokine cxcl8 and its receptor, cxcr1, are expressed by zebrafish endothelial cells, and we identify cxcl8/cxcr1 signaling as a positive regulator of HSPC colonization. Single-cell tracking experiments demonstrated that this is a result of increases in HSPC–endothelial cell “cuddling,” HSPC residency time within the CHT, and HSPC mitotic rate. Enhanced cxcl8/cxcr1 signaling was associated with an increase in the volume of the CHT and induction of cxcl12a expression. Finally, using parabiotic zebrafish, we show that cxcr1 acts HSPC nonautonomously to improve the efficiency of donor HSPC engraftment. This work identifies a mechanism by which the hematopoietic niche remodels to promote HSPC engraftment and suggests that cxcl8/cxcr1 signaling is a potential therapeutic target in patients undergoing hematopoietic stem cell transplantation.
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