Proteomic Profiling of Ex Vivo Expanded CD34-Positive Haematopoetic Cells Derived from Umbilical Cord Blood

Figure 1

Umbilical cord blood cells were enriched by MACS and sorted for CD34^high/CD45^low-expression.

(a) Representative development of CD34-expression during expansion. On day 0, cells were enriched by MACS (one column) and sorted for CD34^high/CD45^low-expression (gate R4). Isolated cells were expanded on 6-well plates in cytokine-supplemented media with SCF, TPO, FLT3-lg, and IL-6. After 3 days, most cells still expressed significant amounts of CD34 on the surface while after 7 days, less than 20% could be classified as CD34^high/CD45^low

(b) Expansion rates of total and CD34-positive cells. Within the first 3 days, total cell count increased 2.07-fold (±0.32) while only a slight change in CD34-expression could be observed, hence the amount of CD34⁺ cells also expanded by factor 2.00 (±0.32). Within further 4 days of cytokine-driven expansion, the total cell count reached a value of 25.30-fold (±2.93) while expression of CD34 decreased dramatically, resulting in only a 4.17-fold (±0.32) expansion of cells classified as CD34 positive