Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tuebingen, Tuebingen, Germany.
Department of Dermatology, University Medical Center, Tuebingen, Germany.
J Virol. 2022 Dec 14;96(23):e0149822. doi: 10.1128/jvi.01498-22. Epub 2022 Nov 17.
Persistent infections with high-risk human papillomaviruses (HR-HPV) from the genus alpha are established risk factors for the development of anogenital and oropharyngeal cancers. In contrast, HPV from the genus beta have been implicated in the development of cutaneous squamous cell cancer (cSCC) in epidermodysplasia verruciformis (EV) patients and organ transplant recipients. Keratinocytes are the target cells for HPV, but keratinocyte models to investigate the replication and oncogenic activities of beta-HPV genomes have not been established. A recent study revealed, that beta-HPV49 immortalizes normal human keratinocytes (NHK) only, when the viral E8^E2 repressor () is inactivated (T. M. Rehm, E. Straub, T. Iftner, and F. Stubenrauch, Proc Natl Acad Sci U S A 119:e2118930119, 2022, https://doi.org/10.1073/pnas.2118930119). We now demonstrate that beta-HPV8 and HPV38 wild-type or genomes are unable to immortalize NHK. Nevertheless, HPV8 and HPV38 express and oncogenes and other transcripts in transfected NHK. Inactivation of the conserved and replication genes reduces viral transcription, whereas genomes display enhanced viral transcription, suggesting that beta-HPV genomes replicate in NHK. Furthermore, growth of HPV8- or HPV38-transfected NHK in organotypic cultures, which are routinely used to analyze the productive replication cycle of HR-HPV, induces transcripts encoding the capsid gene, suggesting that the productive cycle is initiated. In addition, transcription patterns in HPV8 organotypic cultures and in an HPV8-positive lesion from an EV patient show similarities. Taken together, these data indicate that NHK are a suitable system to analyze beta-HPV8 and HPV38 replication. High-risk HPV, from the genus alpha, can cause anogenital or oropharyngeal malignancies. The oncogenic properties of high-risk HPV are important for their differentiation-dependent replication in human keratinocytes, the natural target cell for HPV. HPV from the genus beta have been implicated in the development of cutaneous squamous cell cancer in epidermodysplasia verruciformis (EV) patients and organ transplant recipients. Currently, the replication cycle of beta-HPV has not been studied in human keratinocytes. We now provide evidence that beta-HPV8 and 38 are transcriptionally active in human keratinocytes. Inactivation of the viral E8^E2 repressor protein greatly increases genome replication and transcription of the and oncogenes, but surprisingly, this does not result in immortalization of keratinocytes. Differentiation of HPV8- or HPV38-transfected keratinocytes in organotypic cultures induces transcripts encoding the capsid gene, suggesting that productive replication is initiated. This indicates that human keratinocytes are suited as a model to investigate beta-HPV replication.
持续性感染高危型人乳头瘤病毒(HR-HPV)是肛门生殖器和口咽癌发生的既定危险因素。相比之下,β属 HPV 已被牵连到表皮发育不良症(EV)患者和器官移植受者的皮肤鳞状细胞癌(cSCC)的发展中。角朊细胞是 HPV 的靶细胞,但尚未建立用于研究β-HPV 基因组复制和致癌活性的角朊细胞模型。最近的一项研究表明,β-HPV49 仅在病毒 E8^E2 抑制剂()失活时才能使正常人角质形成细胞(NHK)永生化(T.M.Rehm、E.Straub、T.Iftner 和 F.Stubenrauch,Proc Natl Acad Sci U S A 119:e2118930119,2022 年,https://doi.org/10.1073/pnas.2118930119)。我们现在证明,β-HPV8 和 HPV38 野生型或基因组无法使 NHK 永生化。尽管如此,HPV8 和 HPV38 在转染的 NHK 中表达和 癌基因和其他转录本。保守的 和 复制基因的失活降低了病毒转录,而 基因组显示出增强的病毒转录,表明β-HPV 基因组在 NHK 中复制。此外,在器官型培养物中生长的 HPV8 或 HPV38 转染的 NHK,其常用于分析 HR-HPV 的有性复制周期,会诱导编码 衣壳基因的转录本,表明有性周期已启动。此外,HPV8 器官型培养物中的转录模式和 EV 患者中 HPV8 阳性病变的转录模式显示出相似性。总之,这些数据表明 NHK 是分析β-HPV8 和 HPV38 复制的合适系统。高危型 HPV(属α)可导致肛门生殖器或口咽恶性肿瘤。高危 HPV 的致癌特性对其在人角质形成细胞中的分化依赖性复制很重要,人角质形成细胞是 HPV 的天然靶细胞。β属 HPV 已被牵连到表皮发育不良症(EV)患者和器官移植受者的皮肤鳞状细胞癌(cSCC)的发展中。目前,β-HPV 的复制周期尚未在人角质形成细胞中研究。我们现在提供的证据表明,β-HPV8 和 38 在人角质形成细胞中具有转录活性。病毒 E8^E2 抑制剂蛋白的失活大大增加了基因组复制和 和 癌基因的转录,但令人惊讶的是,这并不会导致角质形成细胞永生化。在器官型培养物中分化的 HPV8 或 HPV38 转染的角质形成细胞会诱导编码 衣壳基因的转录本,表明有性复制已启动。这表明人角质形成细胞适合作为研究β-HPV 复制的模型。