The investigation of the role of cytokine from derived epithelial cell for activation γδ T cells in mucosal infection

为了解上皮内淋巴细胞在牙周病发病机制中的作用，通过比较肠道上皮细胞(I-EC)早期产生的IL-15，研究了C57BL/6耐药小鼠和BALB/c易感小鼠口腔感染单核细胞增多性李斯特氏菌的机制。用活的单核细胞增多性乳杆菌，分别在第1、3、5天计数肝、脾、肠系膜淋巴结(MLN)和Peyer‘s斑块(PP)中的细菌。C57BL/6小鼠在所有器官中表现出比BALB/c更高的耐药性。为了了解这些耐药性的差异，我们研究了口腔感染单核细胞增多性李斯特菌时肠上皮内淋巴细胞(I-IEL)的动力学。口腔感染后第1、3、5天，携带CD8αα和CDαβ或TCRαβ和γδ的I-IEL亚群绝对数和比例均无显著差异。因此，这些结果表明口腔感染单核细胞增多性李斯特菌可能不会影响亚单位…。每只小鼠的i-IEL数量较多。接下来，我们研究了口腔感染后I-EC和I-IEL细胞因子产生的差异。单核细胞增多性李斯特菌感染后第1天，C57BL/6小鼠I-EC中高水平表达IL-15 mRNA和IL-15蛋白，而BALB/c小鼠I-EC中低水平表达IL-15和IL-15。同时，C57BL/6小鼠I-IEL对CD_3刺激产生的干扰素-γ的量高于BALB/c小鼠。而BALB/c小鼠的I-IEL在CD3刺激下产生的IL-4水平高于C57BL/6小鼠。Toll样受体(TLR)2被认为是分枝杆菌或革兰氏阳性细菌的细菌脂蛋白的受体。单核细胞增多性李斯特氏菌感染后第1天，C57BL/6小鼠I-EC中IL-15基因转录的部分信号转导分子TLR2的mRNA表达水平升高，提示TLR2的表达与IL-15产生的差异有关，早期产生IL-15的差异可能至少是C57BL/6和BALB/c小鼠对单核细胞增多性李斯特菌易感性差异的部分原因。较少

To know the role of intraepithelial lymphocyte as an etiology of periodontal disease, the mechanism responsible for C57BL/6 as resistance mice and BALB/c as susceptibility mice to oral infection with Listeria monocytogenes were studied by comparing early IL-15 production in intestinal epithelial cells (i-EC).After mice were inoculated p.o. with viable L. monocytogenes, the bacteria in liver, spleen, mesenteric lymph nodes (MLN) and Peyer's patch (PP) were counted on day 1, 3 or 5. C57BL/6 mice were shown higher level of resistance than BALB/c in all organs. To know the difference of these resistance, we investigate kinetics of the intestinal intraepithelial lymphocytes (i-IEL) during oral infection with L.monocytogenes. There were no significant difference in the absolute : nmber and the ratio of i-IEL subpopulations bearing CD8αα and CDαβ or TCRαβ and γδ on day 1, 3 and 5 after oral infection. Thus, these results suggest that oral infection with L.monocytogenes may not affect the subp … More opulation of i-IEL in each mice. Next, we investigate the difference of cytokines production in i-EC and i-IEL after oral infection. High levels of IL-15 mRNA and IL-15 protein in i-EC from C57BL/6 mice were expressed on day 1 after L.monocytogenes infection, whereas in i-EC from BALB/c mice, those were expressed very low. Concurrently, a amount of IFN-γ which was produced by i-IEL from C57BL/6 mice in response to CD3 stimulation were higher than by that from BALB/c mice. While the i-IEL from BALB/c mice produced a higher level of IL-4 upon CD3 stimulation than that of C57BL/6 mice. The toll-like receptor (TLR) 2 has been suggested as a receptor for bacterial lipoproteins from Mycobacteria or Gram-positive bacteria. The mRNA expression level of TLR2, which is recognized to mediate a partly signaling for IL-15 gene transcription, was increased in i-EC from C57BL/6 mice on day 1 after L.monocytogenes infection.These results suggest that TLR2 expression regards difference of IL-15 production, and that the difference in early production of IL-15 by i-EC may at least partly underlie the difference in susceptibility to L.monocytogenes between C57BL/6 and BALB/c mice. Less