| 摘要 |
Provided is a process of replicating a virus in avian embryonic derived stem cells obtained by A) culturing avian embryonic cells in a complete culture medium complemented in serum containing: exogenous growth factors comprising the trophic factors SCF, IGF-1 and bFGF, and cytokines L1F, interleukin 11, interleukin 6, interleukin 6 receptor, CNTF, oncostatin or cardiotrophin; and an inactivated feeder layer; B) passage by modifying the culture medium so as to obtain the withdrawal of said exogenous growth factors, of the serum and/or of the feeder layer; C) establishing adherent or non-adherent cell lines capable of proliferating in a basal medium in the absence of exogenous growth factors, serum and/or inactivated feeder layer, said process of replicating a virus comprising the steps of: a) proliferating said stem cells in a cultivation vessel, in suspension as clumped cells, in a first serum-free medium allowing the stem cells to aggregate to each other to form clumps during said step A; infecting said stem cells with the selected virus when the cell density is of at least 1.5 million cells/ml; c) shortly before infection, simultaneously to infection, or shortly after infection adding to the cell culture a second serum-free medium; d) further culturing said infected cells in order to allow virus replication; and e) harvesting said virus. Further provided is a vaccine obtained by the process. |
