Department of Physiology, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Infect Immun. 2019 Jul 23;87(8). doi: 10.1128/IAI.00270-19. Print 2019 Aug.
Neutrophils are the most abundant circulating leukocytes in humans and are essential for the defense against invading pathogens. Like many other cells of an organism, neutrophils can be highly influenced by the diet. We have previously described that mice fed a high-fat diet rich in polyunsaturated fatty acids (HFD-P) present a higher frequency of neutrophils in bone marrow than mice fed a high-fat diet rich in saturated fatty acids (HFD-S). Interestingly, such an increase correlated with improved survival against bacterium-induced sepsis. In this study, we aimed to investigate the effects of dietary polyunsaturated and saturated fatty acids on neutrophil homeostasis. We found that HFD-P specifically induced the accumulation of neutrophils in the marginal pools of the spleen and liver. The accumulation of neutrophils in the spleen was a result of a dual effect of polyunsaturated fatty acids on neutrophil homeostasis. First, polyunsaturated fatty acids enhanced the recruitment of neutrophils from the circulation into the spleen via chemokine secretion. Second, they delayed neutrophil cell death in the spleen. Interestingly, these effects were not observed in mice fed a diet rich in saturated fatty acids, suggesting that the type of fat rather than the amount of fat mediates the alterations in neutrophil homeostasis. In conclusion, our results show that dietary polyunsaturated fatty acids have a strong modulatory effect on neutrophil homeostasis that may have future clinical applications.
中性粒细胞是人体中最丰富的循环白细胞，对于抵御入侵病原体至关重要。与生物体的许多其他细胞一样，中性粒细胞可以受到饮食的高度影响。我们之前曾描述过，喂食富含多不饱和脂肪酸的高脂肪饮食（HFD-P）的小鼠骨髓中的中性粒细胞频率高于喂食富含饱和脂肪酸的高脂肪饮食（HFD-S）的小鼠。有趣的是，这种增加与对抗细菌引起的败血症的存活率提高有关。在这项研究中，我们旨在研究饮食中的多不饱和和饱和脂肪酸对中性粒细胞动态平衡的影响。我们发现 HFD-P 特异性地诱导中性粒细胞在脾脏和肝脏的边缘池中积累。中性粒细胞在脾脏中的积累是多不饱和脂肪酸对中性粒细胞动态平衡的双重作用的结果。首先，多不饱和脂肪酸通过趋化因子分泌增强了从中循环招募中性粒细胞进入脾脏的作用。其次，它们延缓了中性粒细胞在脾脏中的细胞死亡。有趣的是，这些作用在喂食富含饱和脂肪酸的饮食的小鼠中并未观察到，这表明是脂肪的类型而不是脂肪的量调节了中性粒细胞动态平衡的改变。总之，我们的结果表明，饮食中的多不饱和脂肪酸对中性粒细胞动态平衡具有很强的调节作用，可能具有未来的临床应用价值。
