In vitro generation of dendritic cells derived from cryopreserved CD34(+) cells mobilized into peripheral blood in lymphoma patients

Background Dendritic cells (DC) ave APC that initiate primary T-cell dependent immune responses. They have deem shown to be generated from CD34(+) cells in BM, p lacental/umbilical cord blood (CB), and G-CSF mobilized peripheral blood CD 34(+) cells (PBSC). In recent clinical studies, DC were used as a vaccine f or cancer patients and showed induction of their antitumor effects. Cryopre servation of CD34(+) cells is important to extend the availability of cellu lar therapy with DC. However, little is known about the effect of cryoprese rvation on the functional maturation of DC. Methods PBSC harvested from lymphoma patients mobilized with G-CSF and undergoing l eukapheresis were cryopreserved at -135 degrees C for 3 days. Freshly isola ted or cryopreserved PBSC were cultured with GM-CSF/SCF/tumor necrosis fact or-alpha (TNF-alpha). After 14 days of culture, DC were harvested, washed, and used for phenotypical and functional analysis. Results Cryopreserved PBSC, as well as freshly-isolated PBSC cultured for 14 days, gave rise to CD1a(+)/CD4(+)/CD11c(+)/CD14low(+)/CD25(-)/CD40(+)/CD45RO(+)/C D80(+)/CD83(+)/CD86(+)/HLA-DR+ cell with dendritic morphology. DC derived f rom cryopreserved PBSC mobilized with G-CSF showed a similar endocytic capa city and chemotactic migratory capacities when compared with DC derived fro m freshly-isolated G-CSF mobilized PBSC. These DC also exhibited similar ca pacities in the primary allogeneic T-cell response. Discussion These results indicate that cryopreserved G-CSF mobilized PBSC cultured wit h GM-CSF/SCF/TNF-alpha gave rise to DC that were morphologically, phenotypi cally and functionally similar to DC derived from fresh G-CSF mobilized PBS C. The observation indicates the clinical usefulness of cryopreserved CD34( +) cells from lymphoma patients.