Zhu Lei, Li Weihua, Qi Gongjian, Liu Na, Sheng Liping, Shang Lei, Qi Boxiang
Department of Intensive Care Unit, Xuzhou Children's Hospital, Xuzhou, Jiangsu 221006, P.R. China.
Exp Ther Med. 2017 May;13(5):2263-2266. doi: 10.3892/etm.2017.4245. Epub 2017 Mar 20.
Immunological response is thought to play a crucial role in the development of a severe hand-foot-and-mouth disease (HFMD) infection in children, but the mechanisms remain largely unknown. This study was designed to help in elucidating the immunopathological pathways involved in the disease by quantifying Toll-like receptor (TLR) mRNAs, MAPK factors and cytokine levels in children experiencing the disease. A total of 86 enterovirus 71 (EV71)-infected HFMD children (49 with mild and 27 with severe disease), along with 30 healthy children were involved in the study. Peripheral vein blood samples were collected from each individual, and used to isolate peripheral blood mononuclear cells (PBMCs) for mRNA extraction and sera for measuring levels of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-6 and IL-10. The average expression levels of TLR3, TLR4, TLR7 and TLR8 mRNA in PBMCs of children with severe HFMD were significantly higher than those in the other children, the lowest values were found in the healthy control group (P<0.05). The expression levels of TLR2 and TLR9 mRNA were not significantly different (P>0.05) among the groups. Additionally, the expression levels of TNF-α, IFN-γ, IL-6 and IL-10 in the serum of the children in the severe group were significantly higher than those in the other two groups, and the lowest values were again found in the control group (P<0.05). Pearson correlation analysis showed that the TLR3, TLR4, TLR7 and TLR8 mRNA levels in PBMCs were positively correlated with the TNF-α, IFN-γ, IL-6 and IL-10 levels in the serum (P<0.05). Furthermore, the expression levels of the ERK, JNK and p38 mRNA in PBMCs of children in the severe group were significantly higher than those in the other two groups, with the lowest values being in the control group (P<0.05). Pearson correlation analysis showed that the TLR3, TLR4, TLR7 and TLR8 mRNA levels in PBMCs were positively correlated with ERK, JNK and p38 mRNA levels (P<0.05). The results of our study seem to indicate that the high expression levels of TLR3, TLR4, TLR7 and TLR8 induced in severe EV71 HFMD regulate the expression of cytokines by MAPK signaling pathway and negatively affect the ability of the organism to resolve the infection. Further studies are needed to test the hypothesis that immuno-modulation would be an effective treatment approach in pediatric cases of severe HFMD.
免疫反应被认为在儿童严重手足口病（HFMD）感染的发展中起关键作用，但其机制仍 largely 未知。本研究旨在通过量化患该病儿童的 Toll 样受体（TLR）mRNA、丝裂原活化蛋白激酶（MAPK）因子和细胞因子水平，帮助阐明该疾病涉及的免疫病理途径。共有 86 例肠道病毒 71 型（EV71）感染的 HFMD 儿童（49 例轻症和 27 例重症）以及 30 例健康儿童参与了本研究。从每个个体采集外周静脉血样本，用于分离外周血单个核细胞（PBMCs）以提取 mRNA，以及采集血清用于测量肿瘤坏死因子（TNF）-α、干扰素（IFN）-γ、白细胞介素（IL）-6 和 IL-10 的水平。重症 HFMD 儿童 PBMCs 中 TLR3、TLR4、TLR7 和 TLR8 mRNA 的平均表达水平显著高于其他儿童，健康对照组中的值最低（P<0.05）。TLR2 和 TLR9 mRNA 的表达水平在各组间无显著差异（P>0.05）。此外，重症组儿童血清中 TNF-α、IFN-γ、IL-6 和 IL-10 的表达水平显著高于其他两组，对照组中的值再次最低（P<0.05）。Pearson 相关性分析表明，PBMCs 中 TLR3、TLR4、TLR7 和 TLR8 mRNA 水平与血清中 TNF-α、IFN-γ、IL-6 和 IL-10 水平呈正相关（P<0.05）。此外，重症组儿童 PBMCs 中 ERK、JNK 和 p38 mRNA 的表达水平显著高于其他两组，对照组中的值最低（P<0.05）。Pearson 相关性分析表明，PBMCs 中 TLR3、TLR4、TLR7 和 TLR8 mRNA 水平与 ERK、JNK 和 p38 mRNA 水平呈正相关（P<0.05）。我们的研究结果似乎表明，重症 EV71 HFMD 中诱导的 TLR3、TLR4、TLR7 和 TLR8 的高表达通过 MAPK 信号通路调节细胞因子的表达，并对机体清除感染的能力产生负面影响。需要进一步研究来验证免疫调节是否是重症 HFMD 儿科病例的有效治疗方法这一假设。
