Lügering Andreas, Kucharzik Torsten
Department of Medicine B, University of Münster, Albert-Schweitzer-Strasse 33, 48129 Münster, Germany.
Ann N Y Acad Sci. 2006 Aug;1072:210-7. doi: 10.1196/annals.1326.015.
The intestinal immune system includes several organized structures, such as Peyer's patches, isolated lymphoid follicles (ILFs), cryptopatches (CPs) as well as mesenteric lymph nodes (MLNs) that constitute an extensive network with other nonorganized parts, such as intraepithelial and lamina propria lymphocytes. CPs are small clusters of lymphoid cells with an immature lymphocyte phenotype and dendritic cells. Initial observations in transfer experiments suggested that the immature lymphocytes are T cell precursors and CPs are a potential site of extrathymic intraepithelial lymphocyte (IEL) differentiation. This feature has recently been challenged particularly by the observation that CP cells express the orphan receptor RORgammat and are phenotypically indistinguishable from lymphoid tissue-inducer (LTi) cells, suggesting that CP cells are the adult counterpart of fetal LTi cells. In addition, the chemokine receptor CCR6 is specifically expressed by precursor cells within CPs and its deletion inhibits the development of ILFs. Therefore, it is likely that ILFs derive from CPs under the control of CCR6 under inflammatory conditions and might constitute a valuable target for anti-inflammatory therapies.
肠道免疫系统包括几个有组织的结构，如派尔集合淋巴结、孤立淋巴滤泡（ILF）、隐窝斑（CP）以及肠系膜淋巴结（MLN），它们与其他无组织的部分，如上皮内淋巴细胞和固有层淋巴细胞，构成一个广泛的网络。CP是具有未成熟淋巴细胞表型的淋巴细胞和树突状细胞的小簇。转移实验的初步观察表明，未成熟淋巴细胞是T细胞前体，CP是胸腺外上皮内淋巴细胞（IEL）分化的潜在部位。最近，这一特征受到了挑战，特别是观察到CP细胞表达孤儿受体RORγt，并且在表型上与淋巴组织诱导细胞（LTi）无法区分，这表明CP细胞是胎儿LTi细胞的成年对应物。此外，趋化因子受体CCR6在CP内的前体细胞中特异性表达，其缺失会抑制ILF的发育。因此，ILF很可能在炎症条件下在CCR6的控制下从CP衍生而来，并且可能构成抗炎治疗的一个有价值的靶点。
