Studies of regulatory signaling molecule SMAD in pediatric allergic and chronic inflammatory diseases

辅助性T细胞根据其细胞因子产生谱主要分为三大类：Th 1、Th 2和Th 3细胞。Th 1细胞产生IL-2、IFN-γ和TNF-α，主要参与细胞介导的免疫反应。Th 2细胞产生IL-4、IL-5、IL-9、IL-10和IL-13，其促进嗜酸性粒细胞增多并通常增强抗体应答，包括IgE介导的过敏性患者。最后，Th 3细胞通过产生TGF-β来调节Th 1和Th 2细胞因子的产生。TGF-β具有广泛的调节活性，包括诱导口服耐受、有效的抗炎作用、粘膜伊加表达以及对上皮细胞增殖和分化的影响。TGF-β通过受体丝氨酸激酶发出信号，然后磷酸化并从而激活转录因子Smad 2和Smad 3。Smad 4是一种常见的介质，然后与这些激活的分子结合，并可以向细胞核发送信号。Smad 7分子也可作为拮抗性Smad发挥作用，并可抑制Smad 7的表达。 ...更多信息 t TGF-β介导的Smad 3磷酸化以减弱TGF-β向细胞核的信号传导。在这个项目中，我们组织了一系列研究来检查TGF-β在慢性炎症性疾病中的作用。我们还研究了婴儿早期TGF-β信号传导的免疫发育。我们首先研究了一名患有特应性皮炎、肾病综合征、胰岛素依赖型糖尿病和原田病的女孩。由于Th 1和Th 2介导的慢性炎性疾病存在于单个患者中，因此研究了TGF-β/Smad调节信号。为了评估早产儿的免疫发育，我们检测了早产儿0、14和28天血清细胞因子水平和Th 2和Th 1趋化因子受体CCR 4和CCR 5的表达。血清IL-4水平在第14天表现出增加，但在第28天降低至初始水平。血清TGF-β_1水平在第14天显著升高，但在第28天降至初始水平。RT-PCR结果显示，出生后不久，CCR 5-mRNA有表达，而CCR 4-mRNA无表达。此后，CCR 4-mRNA的表达显著增加，并在第28天达到CCR 5-mRNA的表达水平。因此，从第0天到第28天，CCR 4 ^+ CD 4 ^+细胞显著增加，而CCR 5 ^+ CD 4 ^+细胞未通过FACS分析。IL-4和TGF-β_1的合成增加以及CCR 4 ^+ CD 4 ^+细胞的增加表明，在母体外的环境下，即使在早产儿出生后不久，也有向Th 2应答的偏向，而他们可能能够在出生后不久发展Th 1介导的应答。短B.breve组血清TGF-β_1水平在第14天升高，第28天仍维持在较高水平。在第28天，相对于对照组的水平，短B.breve给药后Smad 3的mRNA表达水平增强，Smad 7（拮抗性Smad）的mRNA表达水平降低。这些结果表明，给早产儿施用短B.breve可上调TGF-β1信号传导，并可能有益于减轻这些婴儿的炎症和过敏反应。少

Helper T cells are classified mainly into three broad types according to their cytokine production profile : Th1,Th2, and Th3 cells. Thi1 cells produce IL-2,IFN-γ and TNF-α and mainly involve cell-mediated immunological reactions. Th2 cells produce IL-4,IL-5,IL-9,IL-10, and IL-13, which promote eosinophilia and generally boost antibody responses including IgE-mediated allergic patients. Lastly, Th3 cells regulate Th1 and Th2 cytokine production by producing TGF-β. TGF-β has a broad spectrum of activities in regulation, including induction of oral tolerance, potent anti-inflammatory effects, mucosal IgA expression, and effects on epithelial cell proliferation and differentiation. TGF-β signals through a receptor serine kinase that then phosphorylates and thereby activates transcription factors Smad2 and Smad3. Smad4, a common mediator, then binds to these activated molecules and can send signals to the nucleus. The Smad7 molecule may also function as an antagonistic Smad, and may inhibi … More t TGF-β-mediated Smad3 phosphorylation to attenuate TGF-β signaling to the nucleus. In this project, we organized a series of studies to examine the effects of TGF-β in chronic inflammatory diseases. We have also investigated the immunological development if TGF-β signaling in early infancy.We have first investigated a girl with atopic dermatitis, nephrotic syndrome, insulin dependent diabetes mellitus, and Harada's disease. Since Th1- and Th2-mediated chronic inflammatory diseases are present in a single patient, a TGF-β/Smad regulatory signal was investigated. Enhanced expression of Smad7, an antagonist for TGF-β signaling, was confirmed, suggested that lack of regulatory signaling might contribute chronic inflammatory diseases including her disease status.To evaluate the immunological development of preterm infants, we examined the serum cytokine levels and the expression of Th2 and Th1 chemokine receptors, CCR4 and CCR5, on day 0, 14, and 28 in preterm infants. Serum IL-4 levels exhibited an increase on day 14, but decreased to the initial level on day 28. The significant elevation of serum TGF-β_1 levels was confirmed on day 14 but decreased to the initial level on day 28. The RT-PCR confirmed the expression of CCR5-mRNA soon after birth, while there was no expression of CCR4-mRNA. Thereafter, the expression of CCR4-mRNA increased significantly and reached the level of CCR5-mRNA expression on day 28. Thus, CCR4^+CD4^+ cells were significantly increased from day 0 to 28, while CCR5^+CD4^+ cells were not analyzed by FACS. Increased IL-4 and TGF-β_1 synthesis as well as increased CCR4^+CD4^+ cells suggest that, under extra-maternal circumstances, there is a shift in bias toward Th2 responses even in preterm infants soon after delivery, while they may be capable of developing Th1 mediated responses soon after birth.We, then, examined the effect of probiotics, Bifidobacterium breve, on the immunological system of preterm infants. Serum TGF-β_1 level was elevated on day 14 and remained elevated on day 28 in the B.breve group. Level of mRNA expression was enhanced for Smad3 and reduced for Smad7 (antagonistic Smad) after B.breve administration relative to levels in Controls on day 28. These results demonstrated that the administration of B.breve to preterm infants can up-regulate TGF-β1 signaling and may possibly be beneficial in attenuating inflammatory and allergic reactions in these infants. Less