Tamura Akira, Soga Hiroyuki, Yaguchi Kei, Yamagishi Mai, Toyota Takayoshi, Sato Jo, Oka Yoshitomo, Itoh Tsunetoshi
Division of Immunology and Embryology, Tohoku University School of Medicine, 2-1 Seiryo-Machi, Aoba-Ku, 980-8575, Sendai, Japan.
Cell Tissue Res. 2003 Jul;313(1):47-53. doi: 10.1007/s00441-003-0706-4. Epub 2003 Jun 24.
The intestine, which is exposed to nutrition and to food-derived antigens and microbes including viruses and bacteria, might be an important site for the immune response. Crucial structural and functional differences exist between the small and large intestine, regional differences even having been demonstrated within the small intestine. Accordingly, intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs) might be heterogeneous among the different intestinal regions. The aim of this study has been to describe, as accurately as possible, the numbers and T-cell receptor (TCR) phenotypes of IELs and LPLs present in distinct regions of the murine small intestine under physiological conditions. Using an immunohistological technique to differentiate IELs from LPLs, the differential enumeration of IELs and LPLs in distinct regions of the murine small intestine, based upon their definition originally determined by their location, has been performed for the first time and has demonstrated that (1) there are more IELs than LPLs in the duodenum and jejunum, but more LPLs than IELs in the ileum, (2) in the duodenum and jejunum, TCRgammadelta IELs account for 70%-75% of the total CD3(+) IELs, a much greater percentage than previously reported, (3) the ratio of TCRgammadelta to TCRalphabeta IELs is inverted in the ileum, with more than 75% IELs being TCRalphabeta-positive, (4) the lamina propria forms one functional unit throughout the small intestine in terms of the TCR subset components (TCRalphabeta:TCRgammadelta=3:1), and (5) the ileum is entirely different from other regions of the small intestine. To deepen our understanding of the functional significance of the small intestine as an immunologically competent organ, the precise distributions of IELs and LPLs, the ratio of their various subsets, and the strict distinction of IELs and LPLs, as described in this study, is indispensable.
肠道暴露于营养物质、食物衍生的抗原以及包括病毒和细菌在内的微生物中，可能是免疫反应的重要场所。小肠和大肠之间存在关键的结构和功能差异，甚至在小肠内部也已证实存在区域差异。因此，上皮内淋巴细胞（IELs）和固有层淋巴细胞（LPLs）在不同肠道区域可能是异质性的。本研究的目的是尽可能准确地描述生理条件下小鼠小肠不同区域中IELs和LPLs的数量及T细胞受体（TCR）表型。利用免疫组织学技术区分IELs和LPLs，首次基于最初根据其位置确定的定义，对小鼠小肠不同区域的IELs和LPLs进行了差异计数，结果表明：（1）十二指肠和空肠中IELs比LPLs多，但回肠中LPLs比IELs多；（2）在十二指肠和空肠中，TCRγδ IELs占总CD3(+) IELs的70%-75%，这一比例比先前报道的要高得多；（3）回肠中TCRγδ与TCRαβ IELs的比例相反，超过75%的IELs为TCRαβ阳性；（4）就TCR亚群组成而言（TCRαβ:TCRγδ = 3:1），固有层在整个小肠中形成一个功能单元；（5）回肠与小肠的其他区域完全不同。为了加深我们对小肠作为免疫活性器官功能意义的理解，本研究中所描述的IELs和LPLs的精确分布、其各个亚群的比例以及IELs和LPLs的严格区分是不可或缺的。
