Chemotaxis and in vitro transendothelial migration of hematopoietic progenitor cells in response to LTD4.

(A) The chemotactic effect of LTD4 on CD34⁺ hematopoietic progenitor cells at different concentrations was analyzed in a modified Boyden chamber assay. Addition of LTD4 to the lower chamber of the chemotaxis assay stimulated migration of CD34⁺ cells at an average optimum concentration of 25 nM/L. (B) Using an in vitro assay of transendothelial migration across BM endothelium,6 the percentage of migrating CD34⁺ progenitor cells (14 hours) was approximately 2-fold increased by LTD4 at 50 nM. Both mobilized PB and BM-derived progenitors responded to the cysteinyl leukotriene. *P < .05, LTD4 vs control.