Effects of dietary oils on immune responses and host resistance to fungal infection in psychologically stressed mice

1. 在橄榄油喂养，而不是豆油或鱼油喂养的小鼠中，2周的隔离应激降低了淋巴细胞的增殖反应，减少了淋巴细胞的干扰素γ分泌，增加了淋巴细胞的IL-4分泌。分离应激对橄榄油、大豆油和鱼油喂养的小鼠淋巴细胞花生四烯酸含量分别有显著、中度和无明显影响。在橄榄油喂养的小鼠中，分离应激增加了淋巴细胞对皮质酮抗增殖作用的敏感性。这是首次证明心理应激对淋巴细胞免疫活性的影响可能因膳食脂肪酸组成而异。2. 与大豆油或橄榄油喂养的小鼠相比，鱼油喂养的小鼠肝脏和肾脏中的TBARS水平增加。在隔离应激条件下，饲喂鱼油的小鼠的TBARS水平的增加幅度要小于饲喂相同饮食的群居动物。与单独食用鱼油相比，食用鱼油结合隔离应激可降低肝脏和肾脏中的脂质过氧化水平。3. 食用橄榄油的小鼠对巴西副球虫感染的抗真菌抗性表现出心理应激诱导的降低。大豆油没有观察到这种抗真菌活性的降低。在感染早期，喂食橄榄油的小鼠也表现出心理应激引起的肝脏IFN-γ和IL-6水平的下降。这些结果表明，心理应激对宿主抗真菌感染的影响可能因膳食脂肪酸组成而异。

1. In olive oil-fed, but not soybean oil- or fish oil-fed, mice, a 2-week isolation stress decreased lymphocyte proliferative response, reduced interferon-γ secretion and increased IL-4 secretion by lymphocytes. The isolation stress reduced arachidonic acid content of lymphocytes markedly, moderately, and not at all in the olive oil-, soybean oil-, and fish oil-fed mice, respectively. In the olive oil-fed mice, the isolation stress increased lymphocyte sensitivity to the antiproliferative effect of corticosterone. This is the first demonstration that effect of psychological stress on lymphocyte immunological activities can vary depending upon the dietary fatty acid composition. 2. Fish oil-fed mice showed increased levels of TBARS in their livers and kidneys compared with soybean oil- or olive oil-fed mice. These increases in the TBARS levels in the fish oil-fed mice were less profound under isolation stress conditions, when compared with the group-housed animals on the same diet. Dietary fish oil combined with isolation stress results in lower levels of lipid peroxidation in the liver and kidney compared with dietary fish oil alone. 3. Mice fed olive oil showed psychological stress-induced reduction of antifungal resistance to Paracoccidioides brasiliensis infection. This reduction in antifungal activity was not observed with soybean oil. Mice fed olive oil also showed psychological stress-induced decrease in the liver IFN-γ and IL-6 levels at early stages of infection. These results suggest that effects of psychological stress on host resistance to fungal infection can vary depending upon the dietary fatty acid composition.