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T cells in mice treated with PC61 was approximately twice that in mice treated with PBS. The numbers of tumor-infiltrating CD4+ and natural killer cells were also increased significantly. To test the antimetastatic effects of IL-2 treatment in combination with Treg-cell depletion, human recombinant IL-2 (rIL-2) and PC61 were administered to mice implanted with MC38/ mock cells in the spleen, and hepatic metastasis was investigated. The average liver weight in mice treated with rIL-2 plus PC61 was 1.04 ± ± ± ± 0.03 g, less than that in mice treated with rIL-2 (2.04 ± ± ± ± 0.51 g) or PC61 alone (1.81 ± ± ± ± 0.38 g). We conclude that IL-2-induced antitumor immunity is enhanced by Treg-cell depletion and is due to expansion of the tumor-infiltrating cytotoxic CD8 + T-cell population. (Cancer Sci 2007; 98: [416][417][418][419][420][421][422][423]

Abstract.It is well known that tumor necrosis factor (TNF) can have both contrary and pleiotropic effects in anti-tumor immune response. In the present study, we prepared two different tumor cell-based immunotherapy models: MCA38 adenocarcinoma and GL261 glioma intracranial interleukin-2 (IL-2)-based. Each tumor was transfected to express IL-2 with or without expression of the soluble form of tumor necrosis factor receptor type II (sTNFRII). Although mice in which TNF is blocked survive longer than IL-2 alone (35.2 versus 26 days), the reverse was observed for GL261 glioma. The differential effect on tumor growth implies enhanced TNF sensitivity of GL261 compared to MCA38. This notion is supported by the observation that TNF induces apoptosis in GL261 but not MCA38 tumors. We further examined tumor infiltrating CD11b + F4/80 + macrophages (or tumor-associated macrophages: TAM) for TNF production in vivo and found that TAM express cell surface TNF implying a role in eliminating glioma cells mediated by the cell surface form of TNF.

Capsaicin (CAP), a pungent principle of hot pepper, enhanced the energy metabolism of rats through the beta-adrenergic action of CAP itself. The present study was done to clarify the effects of dietary red pepper on feeding behavior, abdominal fat content and laying performance in laying hens. Single Comb White Leghorn laying hens were given diets containing varying levels of red pepper (0, 2 and 10g/kg diet) ad libitum for 10 weeks. The red pepper contains 0.22% CAP. There were no significant differences in feeding behavior in any treatments. This suggests that the receptor for the pungent stimuli might be deficient in chickens. The abdominal fat content and liver color were not altered by dietary red pepper, being implied that the beta-adrenergic action of CAP might be smaller in chickens than in mammals. Laying performances were hardly influenced by dietary red pepper. Roche color fan score and the redness of egg yolk color significantly increased as the dietary red pepper content increased, but the reverse was true for the yellowness and lightness of egg yolk color. In conclusion, it is difficult to depress the excess fat deposition of laying hens by dietary red pepper through the action of CAP. Dietary red pepper is only available for the egg yolk pigmentation, particularly in redness.

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