Studies On Human Dendritic Cells Differentiated From Cord Blood CD34+ Progenitor Cells By Two-step Culture

Dendritic cells (DCs) are the most potent antigen-presenting cells with a unique ability to stimulate naive T cells and initiate primary immune responses. DCs play a critical roles in innate immunity and adaptive immunity, such as the activation of T cells, the induction and maintenance of peripheral immunological tolerance,the immunological memory controled by B cells. Due to their unique functions, DCs become a natural adjuvant. Numerous studies have shown that DCs generated ex vivo and loaded with tumour antigens can induce therapeutic and protective antitumour immunity. In a recently published assessment, tumour cells, tumour antigens expressed by viral vectors and tumour antigens presented by DCs in patients with various forms of metastatic cancer, the immunal efficient of DC vaccines are much better than others.Although the optimal DC vassines dose is unknown, in human trials published so far, the DCs were usually given at 2~4 week intervals, and at doses between 4~40 million. So it is essential in a trail to get enough number of DC in time. For its excellent amplification potent, hematopeitic stem cells fit to obtain a large mumber DCs compare to Mo. With convention culture method, DCs are induced from HSC in a one step way contain GM-CSF, TNF-a as well as early-effect cytokines.The period of one step method do not exceed 12 days, which limit the yield of DCs. if HSC are expanded in the first step culture and then induced in the second step culture, the yield of DCs boost significantly. So in the part one of our experiments,we explore a two-step culture method to generate a large of DCs differentiated from cord blood CD34~+ cells based on our previous studies. We find that planty of...