Programing of T cell function and development through the manipulation of dietary fat in the early postnatal period

我的NSERC项目的总体目标是建立膳食脂质调节T细胞功能和发育的机制。当T细胞受到外部（即病原体、膳食抗原、微生物群）或内部（即生理老化）环境的挑战时，它们对个体/动物是重要的。T细胞主要在哺乳期和断奶早期发育；然而，母婴饮食在这一过程中的作用尚未确定。发生在生命早期的一个重要的t细胞介导的过程是口服耐受（OT）的发展；辨别有害和无害口腔抗原的能力。流行病学研究发现，在生命早期摄入n-3长链多不饱和脂肪酸（LCPUFA）可降低特应性疾病（不能发展为OT）的风险。我们的研究表明，母体摄入n-3 LCPUFA和磷脂酰胆碱（PC）会影响其后代的T细胞功能。我的NSERC发现基金的目标是建立膳食LCPUFA和PC调节T细胞功能和OT发展的机制。更具体地说，我的目标是：1)确定LCPUFA/PC饲喂的最佳剂量和时间（关键窗口），以支持免疫发育和OT的建立；2)确定饮食中LCPUFA/PC对T细胞功能和OT的影响机制；3)优化母体饮食中的脂肪成分，以促进免疫发育和OT的建立。为了了解这些发育中的免疫功能，我们将饲喂营养充足的饲料，仅在哺乳公鼠（以及随后对幼鼠的交叉模型）感兴趣的脂质上有所不同，并检查断奶和以后生活中对免疫发育的影响。培养耐受能力，将在幼犬中使用两种方法诱导对食物蛋白卵清蛋白（OVA）的全身或粘膜耐受。免疫细胞将从脾脏、肠系膜淋巴结（MLN）和Peyers斑块（PP）中分离出来，并（通过流式细胞术）进行表征，并用于评估它们对“正常生理挑战”的反应能力，这种挑战是通过用丝裂原和食物蛋白刺激它们来确定的。利用机体各部位分离的免疫细胞，我们将通过测定脂肪酸组成和磷脂含量的变化（脂质组学）以及参与对Ag反应和建立OT的筏相关蛋白（T细胞受体、CD4、CD28、LAT、Lck、Fyn、Lyn、CTLA-4、plc - γ1）含量的变化来确定饮食效应的机制

The overall goal of my NSERC program is to establish the mechanisms by which dietary lipids modulate T cell function and development. T cells are important to the individual/animal when they are challenged by their external (i.e. pathogens, dietary antigens, microflora) or internal (i.e. physiological aging) environments. T cells develops primarily during the suckling and the early weaning period; however, the role of the maternal and infant diet on this process has not been established. An important T-cell mediated processes that occurs early in life is the development of oral tolerance (OT); the ability to distinguish between harmful and harmless oral antigens. Epidemiological studies have found that consumption of n-3 long chain polyunsaturated fatty acids (LCPUFA) early in life reduce the risk of atopic diseases (failure to develop OT). Our research, has demonstrated that the maternal intake of n-3 LCPUFA and phosphatidylcholine (PC), programs T cell function in their offspring. The goal of my NSERC Discovery Grant is to establish the mechanisms by which dietary LCPUFA and PC modulate T cell function and development of OT. More specifically my aims are to: 1) determine the optimal dose and timing (critical window) for feeding LCPUFA/PC to support immune development and establishment of OT and 2) determine the mechanism(s) for the effect of dietary LCPUFA/PC on T cell function and OT and 3) optimize the dietary lipid composition of the maternal diet so as to facilitate immune development and establishment of OT. To understand these developmental immunological functions we will feed nutritionally adequate diets differing only in the lipids of interest to lactating dams (and later in a cross over model to the pups) and examine the effects on immune development at weaning and later in life. The ability to develop tolerance, OT will be induced in the pups using two methodologies that induce either systemic or mucosal tolerance to the food protein Ovalbumin (OVA). Immune cells will be isolated from spleen, mesenteric lymph nodes (MLN) and Peyers Patches (PP) and characterized (by flow cytometry) and used to assess their ability to respond to ‘normal physiological challenges’ determined by stimulating them with mitogens and food proteins. Using isolated immune cells from various regions of the body we will establish the mechanism for the diet effects by measuring the change in fatty acid composition and amount of phospholipids (lipidomics) and the amount of raft-associated proteins (T cell receptor, CD4, CD28, LAT, Lck, Fyn, Lyn, CTLA-4, PLCγ1) involved in responding to Ag and establishing OT My NSERC program will provide a fundamental understanding of the role of dietary fats during critical periods of T development and contribute to the unique training of a number of different types of HPQ in the growing field of nutritional immunology.