From the ‡Medical Microbiology Interdisciplinary Program, Graduate School, Chulalongkorn University, Bangkok, Thailand.
§Center of Excellence in Immunology and Immune-mediated Diseases, Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Mol Cell Proteomics. 2018 Nov;17(11):2197-2215. doi: 10.1074/mcp.RA118.000735. Epub 2018 Aug 10.
Interferon lambda (IFN-λ) is a relatively unexplored, yet promising antiviral agent. IFN-λ has recently been tested in clinical trials of chronic hepatitis B virus infection (CHB), with the advantage that side effects may be limited compared with IFN-α, as IFN-λ receptors are found only in epithelial cells. To date, IFN-λ's downstream signaling pathway remains largely unelucidated, particularly via proteomics methods. Here, we report that IFN-λ3 inhibits HBV replication in HepG2.2.15 cells, reducing levels of both HBV transcripts and intracellular HBV DNA. Quantitative proteomic analysis of HBV-transfected cells was performed following 24-hour IFN-λ3 treatment, with parallel IFN-α2a and PBS treatments for comparison using a dimethyl labeling method. The depth of the study allowed us to map the induction of antiviral proteins to multiple points of the viral life cycle, as well as facilitating the identification of antiviral proteins not previously known to be elicited upon HBV infection ( IFITM3, XRN2, and NT5C3A). This study also shows up-regulation of many effectors involved in antigen processing/presentation indicating that this cytokine exerted immunomodulatory effects through several essential molecules for these processes. Interestingly, the 2 subunits of the immunoproteasome cap (PSME1 and PSME2) were up-regulated whereas cap components of the constitutive proteasome were down-regulated upon both IFN treatments, suggesting coordinated modulation toward the antigen processing/presentation mode. Furthermore, in addition to confirming canonical activation of interferon-stimulated gene (ISG) transcription through the JAK-STAT pathway, we reveal that IFN-λ3 restored levels of RIG-I and RIG-G, proteins known to be suppressed by HBV. Enrichment analysis demonstrated that several biological processes including RNA metabolism, translation, and ER-targeting were differentially regulated upon treatment with IFN-λ3 IFN-α2a. Our proteomic data suggests that IFN-λ3 regulates an array of cellular processes to control HBV replication.
干扰素 λ（IFN-λ）是一种相对未被探索但很有前途的抗病毒药物。IFN-λ 最近已在慢性乙型肝炎病毒感染（CHB）的临床试验中进行了测试，其优点是与 IFN-α 相比，副作用可能有限，因为 IFN-λ 受体仅存在于上皮细胞中。迄今为止，IFN-λ 的下游信号通路在很大程度上仍未阐明，特别是通过蛋白质组学方法。在这里，我们报告 IFN-λ3 可抑制 HepG2.2.15 细胞中的 HBV 复制，降低 HBV 转录本和细胞内 HBV DNA 的水平。用 IFN-λ3 处理 24 小时后，对转染 HBV 的细胞进行定量蛋白质组学分析，并使用二甲标记法进行 IFN-α2a 和 PBS 处理的平行比较。该研究的深度使我们能够将抗病毒蛋白的诱导映射到病毒生命周期的多个点上，并且还促进了鉴定以前未知的在 HBV 感染时被诱导的抗病毒蛋白（IFITM3、XRN2 和 NT5C3A）。这项研究还表明，许多参与抗原加工/呈递的效应物上调，表明这种细胞因子通过这些过程的几个重要分子发挥免疫调节作用。有趣的是，免疫蛋白酶体帽的 2 个亚基（PSME1 和 PSME2）上调，而组成性蛋白酶体的帽成分在两种 IFN 处理后下调，表明朝着抗原加工/呈递模式进行协调调节。此外，除了通过 JAK-STAT 途径证实经典的干扰素刺激基因（ISG）转录激活外，我们还揭示 IFN-λ3 恢复了 RIG-I 和 RIG-G 的水平，这两种蛋白已知被 HBV 抑制。富集分析表明，几种生物学过程包括 RNA 代谢、翻译和 ER 靶向在 IFN-λ3 和 IFN-α2a 处理后存在差异调节。我们的蛋白质组学数据表明，IFN-λ3 调节一系列细胞过程以控制 HBV 复制。
