Jiang Yi, Obuseh Francis, Ellis William, Piyathilake Chandrika, Jolly Pauline
Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL.
Nutr Res. 2007 Jul;27(7):400-407. doi: 10.1016/j.nutres.2007.04.016.
Although low plasma vitamin A concentrations are associated with increased incidence or severity of infections such as respiratory tract infection and measles in children, there is a paucity of data on the effect of vitamin A deficiency on the distribution of, and cytokine production by, the different cellular immune subsets in humans. We conducted a cross-sectional study in a district in Ghana to characterize cellular subsets and functional capacity of peripheral blood mononuclear cells from vitamin A deficient and vitamin A sufficient (normal) individuals, and evaluated the relationships between vitamin A concentration in plasma and cellular immune status. We measured the percentages of selected cellular phenotypes and intracellular cytokine expression and describe the differential cellular subset distributions and alterations in cytokine expression in participants with normal and deficient vitamin A concentrations. The major change observed in the constitution of cellular subsets was a decrease in TNF-α expressing CD3-CD56+ NK cells in those with vitamin A deficiency compared with normal individuals. CD4+ T cell proliferation and production of IFN-γ and IL-4 were not statistically different between the two groups. These results support previous studies that demonstrated decreased NK cell activity in vitamin A deficient animals. The decrease in TNF-α expressing NK cells observed in vitamin A deficient individuals in this study could help to explain the decreased resistance to infections observed in those with vitamin A deficiency.
尽管血浆维生素A浓度低与儿童呼吸道感染和麻疹等感染的发病率增加或严重程度相关，但关于维生素A缺乏对人体不同细胞免疫亚群的分布及细胞因子产生的影响的数据却很匮乏。我们在加纳的一个地区进行了一项横断面研究，以表征维生素A缺乏和维生素A充足（正常）个体外周血单个核细胞的细胞亚群和功能能力，并评估血浆中维生素A浓度与细胞免疫状态之间的关系。我们测量了选定细胞表型的百分比和细胞内细胞因子表达，并描述了维生素A浓度正常和缺乏的参与者中不同细胞亚群的分布差异以及细胞因子表达的变化。在细胞亚群构成中观察到的主要变化是，与正常个体相比，维生素A缺乏者中表达TNF-α的CD3-CD56+自然杀伤（NK）细胞减少。两组之间CD4+T细胞增殖以及IFN-γ和IL-4的产生没有统计学差异。这些结果支持了先前的研究，即维生素A缺乏的动物中NK细胞活性降低。在本研究中观察到维生素A缺乏个体中表达TNF-α的NK细胞减少，这可能有助于解释维生素A缺乏者对感染抵抗力下降的现象。
