Blewett Heather J, Gerdung Christopher A, Ruth Megan R, Proctor Spencer D, Field Catherine J
Alberta Institute for Human Nutrition, Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, AB, T6G 2E1, Canada.
Br J Nutr. 2009 Aug;102(4):526-36. doi: 10.1017/S0007114509231722. Epub 2009 Feb 16.
Vaccenic acid (VA) is a ruminant-derived trans-fat and precursor of conjugated linoleic acid (CLA). The objective of the present study was to explore the effects of VA on immune function in a model of the metabolic syndrome, JCR:LA-cp rats. Lean (2:1 mix of +/cp and +/+) and obese (cp/cp) rats, aged 8 weeks, were fed a control (0% VA) or a VA diet (1.5% (w/w) VA) for 3 weeks (twenty rats per group). Splenocytes and mesenteric lymph node (MLN) immune cell phenotypes (flow cytometry), ex vivo cytokine production (ELISA) and phospholipid fatty acid concentrations were measured. Obese rats had higher proportions of splenic macrophages, total T-cells, helper T-cells (total and percentage CD25+), cytotoxic T-cells (total and percentage CD25+) and produced higher concentrations of IL-6 to concanavalin A (ConA) compared with lean rats. Obese rats had lower proportions of MLN T-cells, new T-cells (CD3+CD90+) and cytotoxic T-cells, but higher proportions of helper cells that were CD45RC+, CD25+ and CD4lo, and produced higher concentrations of IL-2, IL-10, interferon gamma and TNFalpha in response to ConA compared with lean rats. VA was higher in plasma phospholipids and both VA and CLA (cis-9, trans-11) were higher in MLN phospholipids compared with control-fed rats. Lean VA-fed rats had lower proportions of MLN and splenocyte CD45RC+ helper cells, and helper T-cells. Splenocytes from VA-fed rats produced 16-23% less IL-2, IL-10 and TNFalpha compared with controls. VA normalised production of MLN IL-2 and TNFalpha in obese rats to levels similar to those seen in lean rats. These results indicate that dietary VA favourably alters the pro-inflammatory tendency of mesenteric lymphocytes from JCR:LA-cp rats.
反式vaccenic酸（VA）是一种源自反刍动物的反式脂肪，也是共轭亚油酸（CLA）的前体。本研究的目的是在代谢综合征模型JCR:LA-cp大鼠中探究VA对免疫功能的影响。8周龄的瘦型（+/cp和+/+按2:1混合）和肥胖型（cp/cp）大鼠被给予对照饮食（0% VA）或VA饮食（1.5%（w/w）VA），持续3周（每组20只大鼠）。测量了脾细胞和肠系膜淋巴结（MLN）免疫细胞表型（流式细胞术）、体外细胞因子产生（ELISA）以及磷脂脂肪酸浓度。与瘦型大鼠相比，肥胖型大鼠脾脏巨噬细胞、总T细胞、辅助性T细胞（总数及CD25+百分比）、细胞毒性T细胞（总数及CD25+百分比）的比例更高，对伴刀豆球蛋白A（ConA）产生的IL-6浓度也更高。与瘦型大鼠相比，肥胖型大鼠MLN中T细胞、新T细胞（CD3+CD90+）和细胞毒性T细胞的比例更低，但CD45RC+、CD25+和CD4lo辅助细胞的比例更高，对ConA产生的IL-2、IL-10、干扰素γ和TNFα浓度也更高。与喂食对照饮食的大鼠相比，血浆磷脂中的VA含量更高，MLN磷脂中的VA和CLA（顺式-9，反式-11）含量也更高。喂食VA的瘦型大鼠MLN和脾细胞中CD45RC+辅助细胞和辅助性T细胞的比例更低。与对照相比，喂食VA的大鼠脾细胞产生的IL-2、IL-10和TNFα减少了16 - 23%。VA使肥胖型大鼠MLN中IL-2和TNFα的产生恢复正常，达到与瘦型大鼠相似的水平。这些结果表明，饮食中的VA有利地改变了JCR:LA-cp大鼠肠系膜淋巴细胞的促炎倾向。
