Interaction between HCMV pUL83 and human AIM2 disrupts the activation of the AIM2 inflammasome.
Interaction between HCMV pUL83 and human AIM2 disrupts the activation of the AIM2 inflammasome.
复制标题
HCMV pUL83 和人 AIM2 之间的相互作用破坏 AIM2 炎性体的激活
DOI：
10.1186/s12985-016-0673-5
复制
发表时间：
2017-02-20
期刊：
影响因子：
4.8
通讯作者：
Fang F
中科院分区：
文献类型：
--
作者：
Huang Y;Ma D;Huang H;Lu Y;Liao Y;Liu L;Liu X;Fang F
研究背景AIM 2是一种胞浆DNA传感器，在双链DNA病原体感染过程中发挥重要作用，但其在人巨细胞病毒（HCMV）感染中的作用尚不清楚。以前，我们发现在HCMV感染的早期阶段AIM 2蛋白水平增加，感染后24小时减少。由于HCMV已经发展出多种策略来逃避宿主免疫，我们推测这种下降可能归因于病毒免疫逃避机制。被膜蛋白pUL 83是一种重要的免疫逃避蛋白，一些研究已经报道pUL 83与特定的细胞蛋白如AIM 2样受体IFI 16结合以影响它们的功能。为了确定是否pUL 83有助于在HCMV感染过程中AIM 2水平的变化，我们研究了pUL 83/AIM 2的相互作用及其对AIM 2 inflamasome activation.MethodsWe的影响构建质粒表达重组pUL 83和AIM 2蛋白的双杂交和化学发光测定。利用免疫共沉淀和免疫荧光共定位技术，我们证实了pUL 83/AIM 2在感染HCMV AD 169株的THP-1源性巨噬细胞中的相互作用。此外，通过研究表达AIM 2、凋亡相关斑点样蛋白（ASC）、caspase-1和IL-1β前体的重组HEK 293 T细胞中炎性小体相关蛋白的表达和裂解，我们评估了pUL 83对AIM 2炎性小体的影响。将pUL 83表达载体转染重组HEK 293 T细胞，经poly（dA：dT）刺激后，AIM 2炎性小体相关蛋白的表达和活化明显降低。结论pUL 83在HCMV感染早期与AIM 2在胞浆中相互作用。pUL 83/AIM 2相互作用解除了AIM 2炎性体的激活。这些发现揭示了一种新的策略，免疫逃逸的HCMV，这可能有助于潜伏感染。
BackgroundAIM2, a cytosolic DNA sensor, plays an important role during infection caused by pathogens with double-stranded DNA; however, its role in human cytomegalovirus (HCMV) infection remains unclear. Previously, we showed an increase in AIM2 protein levels during the early stage of HCMV infection and a decrease 24 h post infection. Because HCMV has developed a variety of strategies to evade host immunity, we speculated that this decline might be attributed to a viral immune escape mechanism. The tegument protein pUL83 is an important immune evasion protein and several studies have reported that pUL83 binds to specific cellular proteins, such as AIM2-like receptor IFI16, to affect their functions. To determine whether pUL83 contributes to the variation in AIM2 levels during HCMV infection, we investigated the pUL83/AIM2 interaction and its impact on the AIM2 inflammasome activation.MethodsWe constructed plasmids expressing recombinant pUL83 and AIM2 proteins for two-hybrid and chemiluminescence assays. Using co-immunoprecipitation and immunofluorescent co-localization, we confirmed the interaction of pUL83/AIM2 in THP-1–derived macrophages infected with HCMV AD169 strain. Furthermore, by investigating the expression and cleavage of inflammasome-associated proteins in recombinant HEK293T cells expressing AIM2, apoptosis-associated speck-like protein (ASC), pro-caspase-1 and pro-IL-1β, we evaluated the effect of pUL83 on the AIM2 inflammasome.ResultsAn interaction between pUL83 and AIM2 was detected in macrophages infected with HCMV as well as in transfected HEK293T cells. Moreover, transfection of the pUL83 expression vector into recombinant HEK293T cells stimulated by poly(dA:dT) resulted in reduced expression and activation of AIM2 inflammasome-associated proteins, compared with the absence of pUL83.ConclusionsOur data indicate that pUL83 interacts with AIM2 in the cytoplasm during the early stages of HCMV infection. The pUL83/AIM2 interaction deregulates the activation of AIM2 inflammasome. These findings reveal a new strategy of immune evasion developed by HCMV, which may facilitate latent infection.