Mac-1 (CD11b/CD18) and CD45 mediate the adhesion of hematopoietic progenitor cells to stromal cell elements via recognition of stromal heparan sulfate

摘要: Hematopoiesis is regulated by two sets of signals, those generated cytokines and when precursor cells interact with bone marrow (BM) stroma. The intimate contact between precursors stroma appears to be mediated multiple, different receptor-ligand binding events. To identify pairs mediating the adhesion hematopoietic stroma, an in vitro model hematopoiesis was used. This involved coculturing BM-derived, interleukin-3 (IL-3)-dependent, multipotential cells, FCDP-mix A4 (A4) a stromal equivalent embryonic mesenchymal cell line, Swiss 3T3 (3T3). In coculture, survive, proliferate, differentiate absence exogenous IL-3, providing they are attached surface. By using detergent lysates surface-biotinylated molecules that bind could detected either fluorescein isothiocyanate (FITC)-streptavidin or FITC-antibody staining flow cytometry. Using this approach beta 2 integrin, Mac-1, CD45, receptor-type tyrosine phosphatase, were identified as on surface cells. Various glycosaminoglycans (GAGs), particularly heparin heparan sulfate, blocked CD45 Mac-1 similarly these GAGs. Removal heparin-binding from diminished digestion heparinase abolished Mac-1. data suggest sulfate ligand for both but recognize structural motifs.