Influenza Division, National Center for Immunization and Respiratory Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
J Infect Dis. 2013 Feb 1;207(3):501-10. doi: 10.1093/infdis/jis527. Epub 2012 Sep 4.
Protein energy malnutrition (PEM), a common cause of secondary immune deficiency in children, is associated with an increased risk of infections. Very few studies have addressed the relevance of PEM as a risk factor for influenza.
We investigated the influence of PEM on susceptibility to, and immune responses following, influenza virus infection using isocaloric diets providing either adequate protein (AP; 18%) or very low protein (VLP; 2%) in a mouse model.
We found that mice maintained on the VLP diet, when compared to mice fed with the AP diet, exhibited more severe disease following influenza infection based on virus persistence, trafficking of inflammatory cell types to the lung tissue, and virus-induced mortality. Furthermore, groups of mice maintained on the VLP diet showed significantly lower virus-specific antibody response and a reduction in influenza nuclear protein-specific CD8(+) T cells compared with mice fed on the AP diet. Importantly, switching diets for the group maintained on the VLP diet to the AP diet improved virus clearance, as well as protective immunity to viral challenge.
Our results highlight the impact of protein energy on immunity to influenza infection and suggest that balanced protein energy replenishment may be one strategy to boost immunity against influenza viral infections.
蛋白质能量营养不良（PEM）是儿童继发性免疫缺陷的常见原因，与感染风险增加有关。很少有研究探讨 PEM 作为流感的危险因素的相关性。
我们使用等热量饮食在小鼠模型中分别提供充足的蛋白质（AP；18%）或极低蛋白质（VLP；2%），研究了 PEM 对流感病毒感染易感性和免疫反应的影响。
与喂食 AP 饮食的小鼠相比，我们发现，喂食 VLP 饮食的小鼠在流感感染后表现出更严重的疾病，表现在病毒持续存在、炎症细胞类型向肺组织的迁移以及病毒诱导的死亡率方面。此外，与喂食 AP 饮食的小鼠相比，喂食 VLP 饮食的小鼠的病毒特异性抗体反应明显降低，流感核蛋白特异性 CD8+T 细胞减少。重要的是，将喂食 VLP 饮食的小鼠的饮食切换为 AP 饮食，可改善病毒清除，并增强对病毒攻击的保护性免疫。
我们的研究结果强调了蛋白质能量对流感感染免疫的影响，并表明平衡的蛋白质能量补充可能是增强对流感病毒感染免疫力的一种策略。
