Incoming human papillomavirus 16 genome is lost in PML protein-deficient HaCaT keratinocytes.
Incoming human papillomavirus 16 genome is lost in PML protein-deficient HaCaT keratinocytes.
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DOI：
10.1111/cmi.12708
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发表时间：
2017-05
影响因子：
3.4
通讯作者：
Sapp M
中科院分区：
文献类型：
--
作者：
Bienkowska-Haba M;Luszczek W;Keiffer TR;Guion LGM;DiGiuseppe S;Scott RS;Sapp M
人乳头瘤病毒 (HPV) 在感染进入过程中以 PML 核体 (NB) 为目标，PML 蛋白对于传入病毒基因组的有效转录非常重要。然而，转录下调被证明是独立于启动子的，因为由乳头瘤病毒颗粒传递的异源启动子也受到影响。为了进一步研究 PML 蛋白在 HPV 侵入中的作用，我们使用 shRNA 敲低 HaCaT 角质形成细胞中的 PML 蛋白。证实了之前的发现，HaCaT 细胞中的 PML 敲除在感染进入后显着降低了 HPV16 转录水平，而不损害结合和运输。然而，当我们量化间期细胞中假基因组的稳态水平时，我们发现与亲本 HaCaT 细胞相比，基因组水平大大降低。由于两种细胞系的核递送具有可比性，因此我们得出结论，成功核递送后必须去除病毒假基因组。通过基因阵列进行的转录组分析表明，克隆 HaCaT 细胞中的 PML 敲低与组成型干扰素 (IFN) 反应相关。 JAK1/2 信号传导的废除可以防止基因组丢失，但并不能恢复病毒转录。相比之下，HeLa 细胞中 PML 蛋白的敲低并不影响 HPV 基因组的传递和转录。 HeLa 细胞被 HPV18 癌基因 E6 和 E7 转化，这些基因已被证明会干扰 JAK/Stat 信号通路。我们的数据表明 PML NB 可以保护传入的 HPV 基因组。此外，他们提供的证据表明 PML NB 是角质形成细胞先天免疫反应的关键调节因子。
Human papillomaviruses (HPVs) target PML nuclear bodies (NBs) during infectious entry and PML protein is important for efficient transcription of incoming viral genome. However, the transcriptional down regulation was shown to be promoter-independent in that heterologous promoters delivered by papillomavirus particles were also affected. To further investigate the role of PML protein in HPV entry, we used shRNA to knockdown PML protein in HaCaT keratinocytes. Confirming previous findings, PML knockdown in HaCaT cells reduced HPV16 transcript levels significantly following infectious entry without impairing binding and trafficking. However, when we quantified steady-state levels of pseudogenomes in interphase cells, we found strongly reduced genome levels compared to parental HaCaT cells. Since nuclear delivery was comparable in both cell lines, we conclude that viral pseudogenome must be removed after successful nuclear delivery. Transcriptome analysis by gene array revealed that PML knockdown in clonal HaCaT cells was associated with a constitutive interferon (IFN) response. Abrogation of JAK1/2 signaling prevented genome loss, however, did not restore viral transcription. In contrast, knockdown of PML protein in HeLa cells did not affect HPV genome delivery and transcription. HeLa cells are transformed by HPV18 oncogenes E6 and E7, which have been shown to interfere with the JAK/Stat signaling pathway. Our data imply that PML NBs protect incoming HPV genomes. Furthermore, they provide evidence that PML NBs are key regulators of the innate immune response in keratinocytes.