Serum-free culture of dendritic cells from patients with chronic myeloid leukemia in vitro and estimation of their cytotoxicity.

Objective: To establish a serum-free culture system of dendritic cells (DCs) from chronic myeloid leukemia (CML) cells so that DCs vaccine may be applied to the adoptive immunotherapy of CML in the near future.

Methods: Fetal calf serum, serum-free medium and autologous serum were used for culture of DCs. The usage of cytokines was classified into two groups: group A (stem cell factor, granulocyte/macrophage colony-stimulating-factor, tumor necrosis factor-alpha and interleukin-4) and group B (granulocyte/macrophage colony-stimulating-factor, tumor necrosis factor-alpha and interleukin-4).

Suppression of in vivo tumorigenicity of rat hepatoma cell line KDH-8 cells by soluble TGF-beta receptor type II.

We have previously reported that transforming growth factor beta (TGF-beta) produced by rat hepatoma cell line KDH-8 cells suppressed the interleukin-2 (IL-2) production of T cells and the tumoricidal activity of macrophages in KDH-8 tumor-bearing rats and that the inhibition of TGF-beta production by low-dose bleomycin restored these activities significantly. In this study, we established three transfectant clones with stable expression of soluble TGF-beta receptor type II (sTRII), namely KT1, KT2 and KT3, and one with an empty vector used as control vector (KV), and then investigated the effects of sTRII on the tumorigenicity of KDH-8 cells and immune responses in syngeneic Wistar King Aptekman/Hok (WKAH) rats. We found that sTRII expressed in sTRII transfectants could abolish growth inhibition of Mv1Lu cells by TGF-beta1 produced by the cells themselves, and that tumor growth of KT2 and KT3 clones in vivo was suppressed significantly compared with that of parent, KV and KT1 clones.