Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON L8S 4M3, Canada.
McMaster Immunology Research Center, Michael G. DeGroote Center for Learning and Discovery, McMaster University, Hamilton, ON L8S 4M3, Canada.
Viruses. 2021 Jan 6;13(1):70. doi: 10.3390/v13010070.
Herpes simplex virus type 2 (HSV-2) is the primary cause of genital herpes which results in significant morbidity and mortality, especially in women, worldwide. HSV-2 is transmitted primarily through infection of epithelial cells at skin and mucosal surfaces. Our earlier work to examine interactions between HSV-2 and vaginal epithelial cells demonstrated that infection of the human vaginal epithelial cell line (VK2) with HSV-2 resulted in increased expression of TRIM26, a negative regulator of the Type I interferon pathway. Given that upregulation of TRIM26 could negatively affect anti-viral pathways, we decided to further study the role of TRIM26 in HSV-2 infection and replication. To do this, we designed and generated two cell lines derived from VK2s with TRIM26 overexpressed (OE) and knocked out (KO). Both, along with wildtype (WT) VK2, were infected with HSV-2 and viral titres were measured in supernatants 24 h later. Our results showed significantly enhanced virus production by TRIM26 OE cells, but very little replication in TRIM26 KO cells. We next examined interferon-β production and expression of two distinct interferon stimulated genes (ISGs), MX1 and ISG15, in all three cell lines, prior to and following HSV-2 infection. The absence of TRIM26 (KO) significantly upregulated interferon-β production at baseline and even further after HSV-2 infection. TRIM26 KO cells also showed significant increase in the expression of MX1 and ISG15 before and after HSV-2 infection. Immunofluorescent staining indicated that overexpression of TRIM26 substantially decreased the nuclear localization of IRF3, the primary mediator of ISG activation, before and after HSV-2 infection. Taken together, our data indicate that HSV-2 utilizes host factor TRIM26 to evade anti-viral response and thereby increase its replication in vaginal epithelial cells.
单纯疱疹病毒 2 型（HSV-2）是生殖器疱疹的主要病因，在全球范围内给女性带来了重大的发病率和死亡率。HSV-2 主要通过感染皮肤和黏膜表面的上皮细胞传播。我们之前的研究工作表明，感染人阴道上皮细胞系（VK2）的 HSV-2 导致负调节 I 型干扰素途径的 TRIM26 表达增加。鉴于 TRIM26 的上调可能会对抗病毒途径产生负面影响，我们决定进一步研究 TRIM26 在 HSV-2 感染和复制中的作用。为此，我们设计并生成了两种源自 VK2 的细胞系，这些细胞系过表达（OE）和敲除（KO）TRIM26。这两种细胞系以及野生型（WT）VK2 均被 HSV-2 感染，24 小时后测量上清液中的病毒滴度。我们的结果显示，TRIM26 OE 细胞的病毒产量显著增加，但 TRIM26 KO 细胞的复制很少。接下来，我们在 HSV-2 感染前后，检查了所有三种细胞系中干扰素-β的产生和两种不同的干扰素刺激基因（ISG），MX1 和 ISG15 的表达。TRIM26 的缺失（KO）显著上调了基线时和 HSV-2 感染后的干扰素-β产生。TRIM26 KO 细胞在 HSV-2 感染前后，MX1 和 ISG15 的表达也显著增加。免疫荧光染色表明，TRIM26 的过表达在 HSV-2 感染前后极大地减少了 ISG 激活的主要介质 IRF3 的核定位。总之，我们的数据表明，HSV-2 利用宿主因子 TRIM26 逃避抗病毒反应，从而增加其在阴道上皮细胞中的复制。
