Ebola virus infection of human PBMCs causes massive death of macrophages, CD4 and CD8 T cell sub-populations in vitro
Ebola virus infection of human PBMCs causes massive death of macrophages, CD4 and CD8 T cell sub-populations in vitro
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DOI：
10.1016/j.virol.2007.02.017
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发表时间：
2007-07-20
期刊：
影响因子：
3.7
通讯作者：
Rollin, Pierre E.
中科院分区：
文献类型：
--
作者：
Gupta, Manisha;Spiropoulou, Christina;Rollin, Pierre E.
埃博拉病毒导致一种通常致命的疾病，其特征是患者免疫反应差和炎症反应高。免疫力低下的原因之一是病毒介导的宿主淋巴细胞凋亡。在这项研究中，我们用扎伊尔埃博拉病毒感染人PBMC，并使用流式细胞术研究不同类型细胞的凋亡。我们已经证明，埃博拉病毒导致CD 4和CD 8 T细胞的旁观者死亡。与灭活病毒处理的细胞相比，病毒感染的细胞在PI第8天具有30-40%的活性半胱天冬酶3（+）、膜联蛋白-V+和Bcl 2（低）表型。60-70%的巨噬细胞在PI第8天也死亡，并具有相似的表型。我们的数据还表明，病毒可以诱导Fas（+）/FasL（+）T淋巴细胞和巨噬细胞的死亡信号，但不上调Fas/FasL在这些细胞中的表达。最后，在感染后纯化CD 4、CD 8和CD 14细胞，并通过RNA酶保护测定研究死亡信号。我们发现在PI第7天，CD 4和CD 8 T细胞中的TRAIL mRNA上调。与未感染的对照和无活性的病毒处理的细胞相比，在TRAIL mRNA水平中观察到CD 4 T细胞的2倍增加和CD 8 T细胞的3倍增加。令人惊讶的是，我们没有发现感染的巨噬细胞和未感染的对照组之间的TRAIL mRNA水平有任何差异。这些数据表明，埃博拉病毒通过引起大量淋巴细胞死亡来逃避免疫反应。此外，他们可能会解释为什么宿主在缺乏CD 4 T细胞的情况下无法产生良好的抗体反应。(C)2007爱思唯尔公司All rights reserved.
Ebola virus causes an often fatal disease characterized by poor immune response and high inflammatory reaction in the patients. One of the causes for poor immunity is virus-mediated apoptosis of lymphocytes in the host. In this study, we infected human PBMCs with Ebola Zaire virus and study apoptosis of different cell types using flow cytometry. We have shown that Ebola virus causes bystander death of CD4 and CD8 T cells. Cells infected with virus had 30-40% active caspase 3(+), annexin-V+ and Bcl2(low) phenotype by day 8 PI as compared to inactivated virus-treated cells. 60-70% of the macrophages were also dead by day 8 PI and had similar phenotype. Our data also showed that virus may induce death signals in Fas(+)/FasL(+) T lymphocytes and macrophages but did not upregulate Fas/FasL expression in these cells. Lastly, CD4, CD8 and CD14 cells were purified after infection and were studied for death signals by RNAse protection assay. We found an upregulation of TRAIL mRNA in CD4 and CD8 T cells on day 7 PI. A two-fold increase in CD4 T cells and three-fold increase in CD8 T cells were observed in TRAIL mRNA levels as compared to uninfected controls and inactive virus-treated cells. Surprisingly, we did not find any difference in TRAIL mRNA levels between infected macrophages and uninfected controls. These data suggest that Ebola virus evades the immune response by causing massive lymphocyte death. In addition, they may give an explanation on why the host is unable to produce a good antibody response in the absence of CD4 T cells. (C) 2007 Elsevier Inc. All rights reserved.