Itk信号转导通路在A型流感病毒与T细胞相互作用中的功能研究

发布时间：2018-01-22 11:17

本文关键词： Itk 甲型流感病毒 T细胞 BALB/c小鼠　出处：《福建农林大学》2012年博士论文　论文类型：学位论文

【摘要】：甲型流感病毒能够引起人和动物的急性呼吸道感染，每年造成大量的人口死亡和经济损失，给全世界的公共健康带来了巨大的威胁。因此，，为了能够更好的了解宿主的抗病毒免疫机制，人们已经做出了大量的研究工作,并已揭示除了体液免疫以外，天然免疫和获得性免疫中多种类型的细胞和细胞因子都参与了宿主的抗病毒免疫反应。然而，尽管对于宿主防御和抗病毒免疫反应机制的了解取得了一定的进展，但是对于引起人和动物严重疾病的流感病毒和宿主免疫系统之间的直接相互作用却知之甚少。而且，对于流感病毒是否对宿主免疫系统的淋巴细胞具有易感性以及流感病毒与淋巴细胞之间的相互作用是否依赖于信号转导通路（如T细胞受体信号）介导的细胞活化也不清楚。为此，本研究中我们利用甲型流感病毒A/WSN/33(H1N1)感染BALB/c小鼠和原代T细胞为模型来检测甲型流感病毒是否对淋巴器官中的T细胞具有易感性。我们发现在病毒感染小鼠的脾脏和胸腺中有一定比例的CD4+T细胞和CD8+T细胞表达流感病毒蛋白。同时，我们发现有相当数量的小鼠原代T细胞表达流感病毒α-2,6唾液酸受体并且这些细胞能直接被甲型流感病毒感染。这些实验揭示了小鼠体内存在一定比例的T细胞对甲型流感病毒具有易感性。而且我们还利用人T细胞白血病细胞系Jurkat来研究流感病毒与Jurkat T细胞的相互作用，尤其关注调控T细胞活化的Tec家族酪氨酸激酶Itk是否参与了甲型流感病毒对T细胞的感染过程。研究结果表明甲型流感病毒A/WSN/33(H1N1)能直接感染Jurkat T细胞，更为有趣的是研究结果表明流感病毒感染导致被感染细胞Itk表达量的增加和Itk向细胞膜募集，并且细胞内PLC-γ1磷酸化的磷酸化水平也有所增加，说明流感病毒感染激活了Itk/PLC-γ1信号转导通路。我们还证实Itk的缺失会抑制甲型流感病毒的复制过程，而Itk的过表达则会促进流感病毒复制。这些结果显示Itk是流感病毒在被感染T细胞中的高效复制所必需的。总之，我们的研究结果表明甲型流感病毒在BALB/c小鼠体内可以直接感染特定的一群T细胞。进一步实验证实甲型流感病毒A/WSN/33(H1N1)能直接感染Jurkat T细胞，并且Itk信号转导通路对甲型流感病毒在Jurkat T细胞中的复制有重要影响。
[Abstract]:Acute respiratory tract influenza A virus can cause human and animal infections, causing deaths and a large economic losses each year, has brought great threat to the world of public health. Therefore, in order to understand better the mechanism of antiviral immunity of the host, people have made a lot of research work, and has revealed the humoral immunity in addition to outside and, natural immune cells and cytokines in various types of immunity are involved in host antiviral immune response. However, although the mechanism of host defense and antiviral immune response solution has made some progress, but the direct interaction between human and animal diseases of influenza virus and the host immune system little is known about. Moreover, with susceptibility and influenza virus and influenza virus for Neisseria whether the host immune system cells Whether the interaction between the Ba cells depends on the signal transduction pathway, such as the T cell receptor signal, is not clear.
Therefore, in this study we use the influenza virus A/WSN/33 (H1N1) as a model to detect influenza virus with susceptibility to T cells in lymphoid organs of mice infected with BALB/c and primary T cells. We found that the virus infected mice spleen and thymus in a certain ratio of CD4+T cells and CD8+T cells with the expression of influenza virus protein. At the same time, we found that there are a considerable number of influenza virus expression in mouse primary T cells -2,6 sialic acid receptors and these cells can directly be influenza A virus infection. These experiments revealed the presence of a certain proportion of mice with T cells with susceptibility to influenza A virus interaction. And we also use human T cell leukemia Jurkat of influenza virus and Jurkat T cells, with particular attention to whether the regulation of T cell activation of Tec family tyrosine kinase Itk in influenza The sense of process of virus infection on T cells. The results show that influenza virus A/WSN/33 (H1N1) Jurkat can infect T cells, more interesting is the results of the study show that influenza virus infected cells leads to increased expression of Itk and recruitment of Itk to the cell membrane, and intracellular PLC- gamma 1 phosphorylation of phosphate the level also increased, indicating influenza virus infection activates Itk/PLC- gamma 1 signaling pathways. We also confirmed the absence of Itk could inhibit the replication of influenza A virus, and the overexpression of Itk may promote the replication of influenza virus. These results show that Itk is required for influenza virus in the infected efficient replication in T cells.
In conclusion, our results suggest that influenza A virus infection in BALB/c mice can direct specific group of T cells. Further experiments confirmed influenza virus A/WSN/33 (H1N1) can infect Jurkat T cells and Itk signal transduction pathway has an important effect on the replication of influenza A virus in Jurkat T cells.

【学位授予单位】：福建农林大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R363

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