Studies on the suppressive factor from parasite of NO synthase and cytokine gene expression in macrophages

我们发现，在LPS刺激下，小鼠腹腔巨噬细胞的排泄/分泌（ES）产物抑制了iNOS、TNF-α和趋化因子的基因表达。我们在本研究中探讨了基因表达的抑制机制。(1)通过比较ES产物在C3H/HeN小鼠和C3H/HeJ小鼠中的作用，TLR4下游的ES产物抑制TNF-α基因的表达，其中在TLR4中观察到点突变。(2)这些抑制作用与巨噬细胞产生的抑制巨噬细胞功能的前列腺素E2、IL-10和分泌性白细胞蛋白酶抑制剂（SLPI）无关。(3) ES产物未降低TNF-αmRNA的稳定性。(4) ES产物处理未降低NF-κB向细胞核的易位和NF-κB与κB元件的结合活性。(5)在J774.1和RAW 264.7细胞中，一氧化氮的产生以及IP-10和TNF-α的基因表达均受到抑制。然后，我们发现这些细胞系对抑制机制的研究是有用的。(6) ES分别抑制phospho-p38 MAP激酶和phospho-ERK以及MAPK抑制剂SB 203580和PD 98059。我们认为这是抑制基因表达的机制之一。(7)胰蛋白酶15 μg/ml或蛋白酶K0.1U/ml处理后，ES产物的抑制作用基本减弱。从这些数据判断，抑制因子应该是一种蛋白质。

We found that excretory/secretory (ES) products of Spirometra erinaceieuropaei suppress the gene expression of iNOS, TNF-α, chemokines in mouse peritoneal macrophages stimulated with LPS.We examined the suppesive mechanism of gene expression in the present investigation.(1) The TNF-α gene expression was suppressed by ES products downstream of TLR4 based on the comparison of the effect of ES products in C3H/HeN miceand C3H/HeJ mice, in which point mutation was observed in TLR4.(2) These suppressive effects were not related with prostaglandin E2, IL-10 and secretory leukocyte protease inhibitor (SLPI) , which are produced in macrophages and suppress the macrophage functions.(3) The stability of TNF-αmRNA was not reduced by the treatment of ES products.(4) The translocation of NF-κB to nucleus and NF-κB binding activity to κB element was not reduced by the treatment of ES products.(5) In J774.1 and RAW 264.7 cell line macrophages, nitric oxide production and gene expression of IP-10 and TNF-α were suppressed. Then, we found that these cell lines are useful in the studies of suppressive mechanism.(6) ES inhibited the phospho-p38 MAP kinase and phospho-ERK as well as MAPK inhibitors, SB 203580 and PD 98059, respectively. We supposed that this is one of the suppressive mechanism of gene expression.(7) The suppressive effect of ES products almost diminished by the treatment with trypsin 15 μg/ml or protease K0.1U/ml. Judging from these data, the supressive factor is supposed to be a protein.