AIMTo provide experimental basis for clinical use of cryopreserved dendritic cells (DCs) by investigating the biological properties of cryopreserved DCs derived from cord blood.

METHODSThe biological discrepancies between unfrozen DCs (UFDC) derived from unfrozen cord blood (UFCB) and DCs from cryopreserved cord blood (CPCB) or cryopreserved DCs (CPDCs) were explored by morphological observation and immunophenotype analysis. Moreover, the stimulating index (SI) in mixed lymphocyte culture and cytotoxic eliminating rate (ER) were measured by MTT.

RESULTSThe TBR of CPCB and CPDCs were 95.8% and 88.7% respectively. Compared to UFCB, CPCB differentiated toward DCs in a delayed and decreased mode, displayed lower expression of CD1a, CD83 and HLA-DR, and had reduced SI and ER. Similarly, the CPDCs became adherent DCs later and grew less in number than UFDCs. After culture, the expression of CD1a, CD83 and HLA-DR as well as SI and ER were lower in CPDCs than those in UFDCs.

CONCLUSIONThough the biological properties of CPCB and CPDCs were injured after cryopreservation, they still had relatively complete basic function. Their recoveries rate were > 85%.