Transendothelial migration of CD34+ and mature hematopoietic cells: an in vitro study using a human bone marrow endothelial cell line.

摘要: To study the role of bone marrow endothelial cells (BMEC) in regulation hematopoietic cell trafficking, we have designed an vitro model transendothelial migration progenitor and their progeny. For these studies, taken advantage a human BMEC-derived line (BMEC-1), which proliferates independent growth factors, is contact inhibited, expresses adhesion molecules similar to BMEC vivo. BMEC-1 monolayers were grown confluency on 3 μm microporous membrane inserts placed 6-well tissue culture plates. Granulocyte-colony stimulating factor (G-CSF )–mobilized peripheral blood CD34+ added monolayer upper chamber plate. After 24 hours coincubation, majority remained nonadherent chamber, while 1.6 ± 0.3% had transmigrated. Transmigrated CD34 expressed higher level CD38 compared with nonmigrating may therefore represent predominantly committed cells. Accordingly, total plating efficiency transmigrated for lineage-committed progenitors was (14.0 0.1 v 7.8% 1.5%). In particular, erythroid 27-fold greater (8.0% 0.8% 0.1%) 5.5-fold unprocessed (2.2% 0.4%). While no difference expression β1-integrin very late activation antigen (VLA)-4 β2-integrin lymphocyte function-associated (LFA)-1 found, L-selectin lost, suggesting that shedding occurred during migration. The number reduced by blocking antibodies LFA-1, VLA-4 inhibitory effect. Continuous coculture remaining transwell resulted proliferation differentiation into myeloid megakaryocytic comprised proliferating precursors such as promyelocytes myelocytes, only mature monocytes granulocytes detected lower chamber. conclusion, support transmigration Therefore, this be used mechanisms involved mobilization homing transplantation trafficking