Symposium 3: Vitamin D and immune function: from pregnancy to adolescence Vitamin D and immune function: an overview
Symposium 3: Vitamin D and immune function: from pregnancy to adolescence Vitamin D and immune function: an overview
复制标题
DOI：
10.1017/s0029665111001650
复制
发表时间：
2012-02-01
影响因子：
7
通讯作者：
Hewison, Martin
中科院分区：
文献类型：
--
作者：
Hewison, Martin
维生素D的免疫调节作用已经被认识了超过四分之一个世纪，但只是在最近几年，这对正常人体生理学的重要性才变得明显。两个关键因素支撑了这一修正后的观点。首先，越来越多的数据将维生素缺乏与普遍的免疫系统疾病联系起来。对地球仪人群中低循环水平前体25-羟基维生素D的认识提高，促使对与维生素D不足相关的健康问题进行流行病学调查。其中突出的是自身免疫性疾病，如多发性硬化症，1型糖尿病和克罗恩病，但最近的研究表明，结核病等感染也可能与低25-羟基维生素D水平有关。扩展维生素D和免疫系统之间联系的第二个因素是我们对促进这种联系的机制的了解。现在很清楚，来自免疫系统的细胞包含将25-羟基维生素D转化为活性1，25-二羟基维生素D以及随后对1，25-二羟基维生素D的反应所需的所有机制。诸如此类的机制对于促进巨噬细胞中对病原体的抗微生物应答以及调节抗原呈递树突细胞的成熟是重要的。后者可能是维生素D控制T淋巴细胞（T细胞）功能的关键途径。然而，T细胞也表现出对1，25-二羟维生素D的直接反应，特别是抑制性调节性T细胞的发育。总的来说，这些观察结果表明，维生素D是连接先天免疫和适应性免疫的关键因素，在维生素D不足的情况下，这两种功能都可能受到损害。
Immunomodulatory actions of vitamin D have been recognised for over a quarter of a century, but it is only in the last few years that the significance of this to normal human physiology has become apparent. Two key factors have underpinned this revised perspective. Firstly, there are increasing data linking vitamin insufficiency with prevalent immune disorders. Improved awareness of low circulating levels of precursor 25-hydroxyvitamin D in populations across the globe has prompted epidemiological investigations of health problems associated with vitamin D insufficiency. Prominent among these are autoimmune diseases such as multiple sclerosis, type 1 diabetes and Crohn's disease, but more recent studies indicate that infections such as tuberculosis may also be linked to low 25-hydroxyvitamin D levels. The second factor expanding the link between vitamin D and the immune system is our improved knowledge of the mechanisms that facilitate this association. It is now clear that cells from the immune system contain all the machinery needed to convert 25-hydroxyvitamin D to active 1,25-dihydroxyvitamin D, and for subsequent responses to 1,25-dihydroxyvitamin D. Mechanisms such as this are important for promoting antimicrobial responses to pathogens in macrophages, and for regulating the maturation of antigen-presenting dendritic cells. The latter may be a key pathway by which vitamin D controls T-lymphocyte (T-cell) function. However, T-cells also exhibit direct responses to 1,25-dihydroxyvitamin D, notably the development of suppressor regulatory T-cells. Collectively these observations suggest that vitamin D is a key factor linking innate and adaptive immunity, and both of these functions may be compromised under conditions of vitamin D insufficiency.