[The Antitumor Activity of G-CSF-Mobilized Peripheral Blood Mononuclear Cells Activated by IL-2 Alone or in...

This study was undertaken to investigate the antitumor activity of rhG-CSF mobilized blood mononuclear cells (G-PBMC) from normal donor activated by rhIL-2 alone or in combination with rhIL-12 in vitro. LDH release assay was used to determine the cytotoxicity activity of G-PBMC against K562 (NK-sensitive) and Raji cells (NK-resistant). The phenotype of the activated G-PBMC was assayed by flow cytometry. Results suggested that the cytotoxicity of the fresh G-PBMC was low before IL-2/IL-12 stimulation. G-PBMC developed marked cytotoxicity after 24 hours of IL-2 activation, with more significant increase for further 48 hours induction. When G-PBMCs were exposed to combination of IL-2 and IL-12, the cytotoxicity was significantly enhanced. The proportions of CD3(+) T cells and CD8(+) T cells were increased when G-PBMC incubated with IL-2 for 72 hours. However, CD56(+) cells were significantly elevated when G-PBMC exposed to IL-2 and IL-12 for 7 days. It is concluded that G-PBMC activated by IL-2 had evident antitumor activity, which was further increased when IL-2 in combination with IL-12. These results demonstrate that IL-2 and IL-12 treatment in vitro might promote the graft-versus-leukemia (GVL) response of G-PBMC.