Regulation of TH2 responses by the pulmonary Clara cell secretory 10-kd protein
Regulation of TH2 responses by the pulmonary Clara cell secretory 10-kd protein
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DOI：
10.1016/j.jaci.2004.05.042
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发表时间：
2004-09-01
影响因子：
14.2
通讯作者：
Huang, SK
中科院分区：
文献类型：
--
作者：
Hung, CH;Chen, LC;Huang, SK
背景：肺Clara细胞分泌10-kd蛋白（CC10）是一种类固醇诱导的、具有潜在抗炎作用的细胞因子，但其是否直接参与调节T细胞反应尚不清楚。目的：研究CC10在调节T(H)2细胞因子表达中的作用。方法：分别采用ELISA和RT-PCR测定细胞因子和GATA-3表达水平。还使用标准方案测定支气管肺泡灌洗液细胞计数。通过免疫细胞化学和蛋白质印迹法测定体内CC10的表达。结果：在体外，发现CC10对抗原致敏小鼠脾细胞中的T(H)2细胞因子表达有显着的、剂量依赖性的抑制作用，但对IFN-γ表达没有影响。在极化的 CD4(+) T(H)2 细胞中也发现了类似的抑制作用，但在初始 CD4(+) T 细胞中却没有。相比之下，CC10能够在初始CD4(+)T细胞中诱导IFN-γ表达，但不能在极化T(H)1细胞中诱导IFN-γ表达。此外，T(H)2 细胞因子表达的抑制伴随着关键转录因子 GATA-3 的减少。重要的是，尽管 T(H)2 细胞因子转录物的衰变动力学没有发现显着变化，但在 CC10 处理的细胞中发现 GATA-3 mRNA 稳定性显着降低。在体内，与模拟转导的小鼠相比，CC10缺陷小鼠中CC10基因的重建导致T(H)2细胞因子水平显着降低，同时GATA-3表达降低，与模拟转导小鼠中观察到的结果相比。结论：这些结果表明，CC10在调节T细胞介导的炎症反应中发挥直接作用。
Background: Pulmonary Clara cell secretory 10-kd protein (CC10) is a steroid-inducible and potentially anti-inflammatory cytokine, but its direct involvement in the regulation of T-cell responses remains unknown.Objective: The role of CC10 in the regulation of T(H)2 cytokine expression was investigated.Methods: The levels of cytokine and GATA-3 expression were determined by ELISA and RT-PCR, respectively. Bronchoalveolar lavage fluid cell counts were also determined by using a standard protocol. CC10 expression in vivo was determined by immunocytochemistry and Western blotting.Results: In vitro, a significant, dose-dependent suppressive effect of CC10 was found on T(H)2 cytokine expression, but not IFN-gamma, in splenocytes of antigen-sensitized mice. A similar suppressive effect was also noted in polarized CD4(+) T(H)2 cells, but not in naive CD4(+) T cells. In contrast, CC10 was able to induce IFN-gamma expression in naive CD4(+) T cells, but not in polarized T(H)1 cells. Furthermore, the suppression of T(H)2 cytokine expression was concomitant with reduction of a critical transcription factor, GATA-3. Of significance was the finding that although no significant change was found in the decay kinetics of T(H)2 cytokine transcripts, a significant decrease in mRNA stability of GATA-3 was seen in CC10-treated cells. In vivo, reconstitution of the CC10 gene in CC10-deficient mice resulted in significantly lower levels of T(H)2 cytokines, concomitant with a decrease in GATA-3 expression, after challenge with Ag compared with those seen in mock-transduced mice, which are associated with reduced levels of pulmonary eosinophilia.Conclusion: These results demonstrate, that CC10 plays a direct role in the regulation of T-cell-mediated inflammatory responses.