Figure 6. ST6Gal-1 suppresses differentiation of human CD34⁺ cells in vitro.

Mobilized human CD34⁺ bone marrow was plated at a density of 0.5 × 10⁶ cells/ml and expanded in vitro in the presence of rhSCF, IL-3, and G-CSF. Before expansion, ST6Gal-1-treated cells were subjected to 3 h of ex vivo sialylation. Aliquots were removed approximately every 2 d and analyzed for cellularity and surface phenotype. (A) Total cellularity in wells receiving rST6Gal-1 vs. control (n = 5). (B) Total cells per well found to express either CD11b or CD34 surface markers as assessed by flow cytometry (n = 5). *P < 0.05; **P < 0.01; ***P < 0.001. (C and D) MPO-stained cytospins of cells collected at the termination of the experiment.