Showing papers by "Jamie Case published in 1997"
TL;DR: It is concluded that MACS enriched, flow sorted CD34+ HUCB cells have greater cytokine mediated expansion potential as measured by progenitor expansion, than MACS enrichment, flow purified CD34+.
Abstract: To determine the optimal cell population for cytokine mediated expansion, we compared the use of Magnetic Cell Sorting (MACS) system enriched CD34+ human umbilical cord blood (HUCB) cells with that of MACS enriched, flow purified CD34+ HUCB cells. Both MACS enriched CD34+ cells and MACS enriched, flow purified CD34+ cells (mean starting purity of CD34+ SC 51.27 ± 7.6% and 96.36 ± 1.34% respectively n = 6) were incubated for seven days with Interleukin-1 (IL-1)+IL-3+Stem Cell Factor (SCF) and showed a fold increase in the number of nucleated cells (10.02 ± 2.6 and 18.23 ± 4.73 respectively) and a reduction in the percentage of CD34+ cells (5.55 ± 1.23% and 12.21 ± 3.29% respectively). An increase in the absolute numbers of CD34+ cells (4.8 × 104 ± 2.3 × 104) was observed with MACS enriched CD34+ cells as compared to no change (1.3 × 105 ± 8.8 × 104) with MACS enriched, flow purified CD34+ cells. An increase in IL-3+GM-CSF+SCF responsive colony forming unit (CFU) (1.7 × 104 ± 9.4 × 103 and 1.6 × 105 ± 7.7 × 104 respectively) was also observed as compared with input values (1.5 × 104 ± 1 × 104 and 2.3 × 104 ± 8.9 × 103 respectively). We conclude that MACS enriched, flow sorted CD34+ HUCB cells have greater cytokine mediated expansion potential as measured by progenitor expansion, than MACS enriched CD34+ HUCB cells.
13 citations
TL;DR: Cord blood has been successfully used to regenerate the hematopoietic system after myeloablative therapy and cytokine mediated expansion depletes CB of cells with stem cell characteristics, but re-exposure of 5-FU resistant expanded CB MNC to5-FU shows growth of some immature and primitive progenitors.
Abstract: Cord blood (CB) has been successfully used to regenerate the hematopoietic system after myeloablative therapy. We investigated whether cytokine mediated expansion depletes CB of cells with stem cell characteristics. CB mononuclear cells (MNC) were enriched for quiescent (primitive) stem cells by incubation with 25 μg/ml 5-Fluorouracil (5-FU) and control CB MNC were incubated with media alone. Cells were then incubated for 7 days with Interleukin-1 (IL1)+IL3+ Stem Cell Factor (SCF) and progenitor content, cell cycle status, nucleated cell count, immunophenotype and resistance to 25 μg/ml 5-FU (primitive stem cells) were evaluated before and after cytokine exposure. Incubation with IL1+IL3+SCF caused an increase (fold expansion) in committed (28.6 ± 8.1), immature (5.8 ± 1.8), and primitive progenitors (4.1 ± 0.8) among control CB MNC compared to a decrease in committed progenitors (0 ± 0) but an increase in both immature (8.4 ± 4.8) and primitive progenitors (7 ± 2.9) among 5-FU resistant CB MNC. An increase in the proportion of CD34+ cells occurred in both fractions. Expanded control CB MNC showed a significant increase in numbers of 5-FU resistant committed (p = 0.024), immature (p = 0.014) and primitive progenitors (p = 0.01) as compared with fresh CB MNC. Re-exposure of 5-FU resistant expanded CB MNC to 5-FU shows growth of some immature and primitive progenitors. Cytokine-mediated expansion of untreated and quiescent CB cells is possible and cytokine-mediated expansion does not deplete CB cells with stem cell characteristics.
2 citations