Our recent proteomic study has shown that plasma protein levels of fetuin-B (Ft-B) and zinc-α2-glycoprotein (ZAG) are significantly elevated in obesity-resistant (OR) rats exposed to a high fat diet. Time profiling of the plasma concentrations of Ft-B and ZAG in OR rats has shown stable regulation of these proteins throughout the entire period of rat breeding. To firmly establish roles for these proteins in lipogenesis, we efficiently knocked down (KD) the genes FETUB and AZGP1 encoding Ft-B and ZAG, respectively, using siRNA in Chang liver cells. Reduced expression of FETUB and AZGP1 led to a significant increase in the expression of lipogenic genes, thereby resulting in higher lipid levels in both KD cells. Collectively with our previous findings, we confirmed that Ft-B was similarly regulated with Ft-A, in that their plasma protein levels were commonly reduced in diet-induced obese rats. Our results provide a possible relationship between reduced plasma protein levels of Ft-B and ZAG and higher risk of diet-induced obesity through impaired fatty acid metabolism in hepatocytes.

Adoptive transfer of immune cells such as T cells and natural killer (NK) cells has emerged as a targeted method of controlling the immune system against cancer. Despite their significant therapeutic potential, efficient methods to generate adequate numbers of NK cells are lacking and ex vivo-expansion and activation of NK cells is currently under intensive investigation. The primary purpose of this study was to develop an effective method for expansion and activation of the effector cells with high proportion of NK cells and increasing cytotoxicity against liver cancer in a short time period. Expanded NK cell-enriched lymphocytes (NKL) designated as “MYJ1633” were prepared by using autologous human plasma, cytokines (IL-2, IL-12 and IL-18) and agonistic antibodies (CD16, CD56 and NKp46) without an NK cell-sorting step. The characteristics of NKL were compared to those of freshly isolated PBMCs. In addition, the cytotoxic effect of the NKL on liver cancer cell was examined in vitro and in vivo. The total cell number after ex vivo-expansion increased about 140-fold compared to that of freshly isolated PBMC within 2 weeks. Approximately 78% of the expanded and activated NKL using the house-developed protocol was NK cell and NKT cells even without a NK cell-sorting step. In addition, the expanded and activated NKL demonstrated potent cytotoxicity against liver cancer in vitro and in vivo. The house-developed method can be a new and effective strategy to prepare clinically applicable NKL for autologous NK cell-based anti-tumor immunotherapy.