Changes in the Cornified Cell Envelope in HPV Infection

HPV 感染时角质化细胞包膜的变化

• 批准号: 6721519
• 负责人: DARRON R BROWN
• 金额: $ 22.58万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6721519
• 关键词: athymic mouse; cell membrane; enzyme inhibitors; enzyme substrate; epithelium; genetic transcription; human papillomavirus; human tissue; membrane proteins; protein glutamine gamma glutamyltransferase; tissue mosaicism; virus cytopathogenic effect; virus protein; xenotransplantation

DESCRIPTION (provided by applicant): The mechanism of HPV transmission at the cellular level is poorly understood. Keratinocytes are the target cells for HPV infection. These cells normally exit the cell cycle and undergo the process of differentiation, including expression of proteins that become components of the cornified cell envelope (CCE). Loricrin, involucrin, small proline rich proteins (SPRs), cytokeratins, and other proteins are covalently cross-linked to make up the CCE. The endpoint of differentiation is a layer of flattened, durable, enucleated CCEs that provides the host with barrier protection. HPV infection does not induce cell lysis, and the mechanism of virion escape from infected keratinocytes is not known. The CCE in its normal, durable state would likely hinder virion release. We theorized that a defective CCE would facilitate release of virions. Our studies support this hypothesis. We have shown that HPV 11 infection induces abnormalities of CCEs, and that desquamated, cornified cells from HPV 11 infected tissue are effective transmitters of infection. We have also shown that the HPV 11 El^E4 protein is associated in vivo with the CCE. Our studies of the effects of HPV 11 infection on the CCE demonstrate a markedly reduced amount of Ioricrin and an abundance of SPR3 in HPV 11-infected epithelium. Our studies, performed on fully differentiated epithelium, suggest that HPV 11 gene products cause the defects in the CCE. In addition, our recent studies show that HPV 11 infection reduces Ioricrin transcription. The combined effects of HPV gene products on the CCE may facilitate the escape of virions, and thus increase the efficiency of HPV transmission. In the current proposal, we will test the hypothesis that HPV 11 induces defects of the CCE, and that these defects can be attributed to the effects of the El^E4 and E2 proteins. To test the hypothesis, we will 1) determine if the El^E4 protein is a TGase substrate or an inhibitor of these enzymes; 2) analyze the effects of El^E4 proteins on the composition and biophysical characteristics of CCEs, and 3) examine of the effects of the E2 on expression of the CCE proteins Ioricrin and small proline rich protein 3.

描述（由申请人提供）：HPV在细胞水平上的传播机制尚不清楚。角化细胞是HPV感染的靶细胞。这些细胞通常退出细胞周期并经历分化过程，包括表达成为角化细胞包膜（CCE）成分的蛋白质。Loricrin, involucrin，小脯氨酸富蛋白（SPRs），细胞角蛋白和其他蛋白共价交联，组成CCE。分化的终点是一层扁平的、持久的、去核的CCEs，它为宿主提供屏障保护。HPV感染不诱导细胞裂解，病毒粒子从感染的角质形成细胞逃逸的机制尚不清楚。CCE在正常的持久状态下可能会阻碍病毒粒子的释放。我们推测有缺陷的CCE会促进病毒粒子的释放。我们的研究支持这一假设。我们已经证明，HPV 11感染诱导CCEs异常，并且从HPV 11感染组织中脱落的角质细胞是感染的有效递质。我们还表明，人乳头状瘤病毒11el ^E4蛋白在体内与CCE相关。我们对HPV 11感染对CCE影响的研究表明，在HPV 11感染的上皮中，碘化甘油的含量显著降低，SPR3的含量丰富。我们在完全分化上皮上进行的研究表明，HPV 11基因产物导致了CCE的缺陷。此外，我们最近的研究表明，HPV 11感染会减少Ioricrin的转录。HPV基因产物对CCE的联合作用可能促进病毒粒子的逃逸，从而提高HPV的传播效率。在目前的提案中，我们将验证HPV 11诱导CCE缺陷的假设，并且这些缺陷可归因于El^E4和E2蛋白的作用。为了验证这一假设，我们将1)确定El^E4蛋白是TGase底物还是这些酶的抑制剂；2)分析El^E4蛋白对CCE组成和生物物理特性的影响；3)检测E2对CCE蛋白Ioricrin和小脯氨酸富蛋白3表达的影响。