Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA.
Biol Trace Elem Res. 2012 May;146(2):230-5. doi: 10.1007/s12011-011-9235-2. Epub 2011 Oct 22.
Selenium (Se) is known to regulate tumorigenesis and immunity at the nutritional and supranutritional levels. Because the immune system provides critical defenses against cancer and the athymic, immune-deficient NU/J nude mice are known to gradually develop CD8(+) and CD4(+) T cells, we investigated whether B and T cell maturation could be modulated by dietary Se and by tumorigenesis in nude mice. Fifteen homozygous nude mice were fed a Se-deficient, Torula yeast basal diet alone (Se-) or supplemented with 0.15 (Se+) or 1.0 (Se++) mg Se/kg (as Na(2)SeO(4)) for 6 months, followed by a 7-week time course of PC-3 prostate cancer cell xenograft (2 × 10(6) cells/site, 2 sites/mouse). Here, we show that peripheral B cell levels decreased in nude mice fed the Se - or Se++ diet and the CD4(+) T cell levels increased in mice fed the Se++ diet. During the PC-3 cell tumorigenesis, dietary Se status did not affect peripheral CD4(+) or CD8(+) T cells in nude mice whereas mice fed with the Se++ diet appeared to exhibit greater peripheral CD25(+)CD4(+) T cells on day 9. Dietary Se status did not affect spleen weight in nude mice 7 weeks after the xenograft. Spleen weight was associated with frequency of peripheral CD4(+), but not CD8(+) T cells. Taken together, dietary Se at the nutritional and supranutritional levels regulates peripheral B and T cells in adult nude mice before and after xenograft with PC-3 prostate cancer cells.
硒（Se）已知在营养和超营养水平上调节肿瘤发生和免疫。由于免疫系统提供了对抗癌症的关键防御，并且无胸腺、免疫缺陷的 NU/J 裸鼠已知逐渐发展出 CD8(+)和 CD4(+)T 细胞，我们研究了膳食 Se 是否可以调节 B 和 T 细胞成熟，以及裸鼠的肿瘤发生是否可以调节。15 只纯合裸鼠单独喂食硒缺乏的酵母基础饲料（Se-）或补充 0.15（Se+）或 1.0（Se++）mg/kg（作为 Na2SeO4）硒 6 个月，随后进行 7 周 PC-3 前列腺癌细胞异种移植（2×10(6)细胞/部位，2 个部位/只小鼠）。在这里，我们表明，喂食 Se-或 Se++饮食的裸鼠外周 B 细胞水平下降，而喂食 Se++饮食的小鼠 CD4(+)T 细胞水平升高。在 PC-3 细胞肿瘤发生期间，膳食 Se 状态不影响裸鼠的外周 CD4(+)或 CD8(+)T 细胞，而喂食 Se++饮食的小鼠在第 9 天似乎表现出更多的外周 CD25(+)CD4(+)T 细胞。异种移植 7 周后，膳食 Se 状态不影响裸鼠的脾脏重量。脾脏重量与外周 CD4(+)，但不是 CD8(+)T 细胞的频率有关。总之，在 PC-3 前列腺癌细胞异种移植前后，营养和超营养水平的膳食 Se 调节成年裸鼠外周 B 和 T 细胞。
