Feasibility of human umbilical cord blood plasma for ex vivo expansion, maturation and activation of human umbilical cord blood derived T lymphocytes

6025 Several different approaches have been used to expand and activate human umbilical cord blood (UCB) T cells ex vivo for infusion into patients with various cancers and infectious diseases. This study was designed to establish a more effective and safe culture system for the ex vivo expansion, maturation and activation of human UCB T cells by investigating the use of autologous or homologous cord blood plasma (ACBP, HCBP), instead of fetal bovine serum (FBS). We collected 36 UCB samples at the time of delivery from uncomplicated normal full-term pregnancies. Fresh umbilical mononuclear cells were isolated by Ficoll-Hypaque density centrifugation. The nonadherent mononuclear cell fractions of each of the 12 samples were cultured with anti-CD3 antibody, IL-2 and individually with ACBP, HCBP or FBS. On day 8, the cellular proliferation rate, cell surface markers and cytotoxicity were assessed. There was no significant difference in proliferation rate among each supplemented medium (P >0.05). The CD3+ was expressed on over 95% of the cells cultured in all three media, compared to the precultured cells. The CD4+/CD8+ ratio of expanded T cells in FBS-supplemented medium appeared to remain greater than one on day 8, but did not in ACBP or HCBP. In ACBP-contained medium, the expression of CD3+CD8+, CD3+CD25+ and CD3+CD45RO+ cells was significantly increased, whereas CD3+CD4+ decreased (P 0.05) among three media, but a significant difference was shown in ACBP-supplemented medium at 40:1 ratio (P