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

1.在橄榄油喂养的小鼠中，而不是大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增殖反应，减少了淋巴细胞的干扰素-γ分泌并增加了IL-4分泌。在橄榄油、大豆油和鱼油喂养的小鼠中，隔离应激分别显著、中度和完全不降低淋巴细胞的花生四烯酸含量。在橄榄油喂养的小鼠中，隔离应激增加了淋巴细胞对皮质酮抗增殖作用的敏感性。这是第一次证明心理应激对淋巴细胞免疫活性的影响可以根据膳食脂肪酸组成而变化。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TBARS水平增加。在隔离应激条件下，喂食鱼油的小鼠中TBARS水平的这些增加与喂食相同饮食的分组饲养动物相比不太明显。与单独食用鱼油相比，食用鱼油结合隔离应激导致肝脏和肾脏中脂质过氧化水平较低。3.喂食橄榄油的小鼠表现出心理应激诱导的抗真菌药物对巴西副球孢子菌感染的耐药性降低。在大豆油中未观察到抗真菌活性的降低。在感染的早期阶段，喂食橄榄油的小鼠也表现出心理应激诱导的肝脏IFN-γ和IL-6水平下降。这些结果表明，心理压力对宿主抵抗真菌感染的影响可以根据膳食脂肪酸组成而变化。

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.