Guo Weimin, Wu Dayong, Li Lijun, Ding Samuel, Meydani Simin Nikbin
Nutritional Immunology Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, United States.
Department of Medicine, Tufts University School of Medicine, Boston, MA, United States.
Front Nutr. 2022 Oct 20;9:1018831. doi: 10.3389/fnut.2022.1018831. eCollection 2022.
Obesity is associated with impaired immune function and increased susceptibility to infection. High fat (HF) diet-induced obesity is a commonly used animal model. However, HF diet itself is known to affect immune function and infection. Thus, it is not discernable which one, HF diet or adiposity, is the major contributor to the observed impairment in immunity and susceptibility to infection in HF diet-induced obesity. We hypothesized that obesity is a major contributor to impaired immune function.
Weight-matched outbred female CD-1 mice (1-mo) were randomly assigned to either a HF (45%) or a low fat (LF, 10%) diet group. Ten week after feeding their respective diets, weight gain in the mice fed the HF diet varied greatly. Thus, based on the average body weight, mice in HF diet group were divided into two sub-groups: HF lean (HF-L) and HF obese (HF-O). After 25-week, mice were immunized with an influenza A/Puerto Rico/8/34 vaccine and boosted 3-week later. Five week after the booster, mice were infected with influenza A/Puerto Rico/8/34 virus, and body weight was recorded daily for 1 month. HF-O mice exhibited significant weight loss after influenza virus challenge compared to LF and HF-L mice while LF and HF-L mice largely maintained their weight to a similar extent.
Our findings suggest that obesity, rather than HF diet, , may impair the efficacy of influenza vaccination.
肥胖与免疫功能受损及感染易感性增加有关。高脂（HF）饮食诱导的肥胖是一种常用的动物模型。然而，已知高脂饮食本身会影响免疫功能和感染情况。因此，在高脂饮食诱导的肥胖中，难以确定是高脂饮食还是肥胖本身是导致观察到的免疫功能受损和感染易感性增加的主要因素。我们假设肥胖是免疫功能受损的主要因素。
将体重匹配的近交系雌性CD - 1小鼠（1月龄）随机分为高脂（45%）或低脂（LF，10%）饮食组。在给予各自饮食10周后，高脂饮食组小鼠的体重增加差异很大。因此，根据平均体重，高脂饮食组小鼠被分为两个亚组：高脂瘦小鼠（HF - L）和高脂肥胖小鼠（HF - O）。25周后，用甲型流感病毒A/波多黎各/8/34疫苗对小鼠进行免疫，并在3周后加强免疫。加强免疫5周后，用甲型流感病毒A/波多黎各/8/34感染小鼠，并连续1个月每天记录体重。与低脂组和高脂瘦小鼠相比，高脂肥胖小鼠在感染流感病毒后体重显著下降，而低脂组和高脂瘦小鼠在很大程度上维持了相似的体重。
我们的研究结果表明，肥胖而非高脂饮食可能会损害流感疫苗接种的效果。
