Molecular genetic dissection of epidermodysplasia verruciformis

描述（由申请方提供）：疣状表皮发育不良（EV）是一种先天性皮肤病，其特征是由β-乳头瘤病毒（EV-HPV）引起的终身播散性和持续性扁平疣病变。EV与非黑色素瘤皮肤癌（NMSC）的风险增加有关，但大多数患者没有其他临床体征（“典型”EV）。2002年发现了EVER 1和EVER 2的病态突变。这些蛋白质在T淋巴细胞中表达，其参与HPV感染的上皮细胞的清除，并且在角质形成细胞中表达，所述角质形成细胞是EV-HPV的特异性靶细胞。EVER蛋白与锌转运蛋白ZnT 1形成复合物，以调节细胞内锌的分布并控制锌依赖性转录活性。在这些患者中缺乏明显的T细胞表型和T细胞相关的感染表明EVER缺陷赋予对EV-HPV易感性的机制涉及角质形成细胞。EVER缺陷约占报告的典型EV病例的75%。我们最近发现，由于严重的T细胞缺陷，EV和其他临床特征（“非典型”EV）患者中存在AR RHOH和MST 1缺陷。这些发现表明，T细胞缺陷可能是持续性EV-HPV感染的基础。为了更好地了解EV的发病机制，并破译针对EV-HPV的免疫的分子和细胞机制，我们的目标是使用无假设的全基因组（GW）筛选方法结合GW连锁（GWL）和全外显子组测序（WES）来鉴定EV的新遗传病因。在我们的15个激酶的队列中，我们获得了一种新的EV致病基因的强有力的初步证据，在两名哥伦比亚激酶和一名法国患者的6名患者中鉴定出CIB 1纯合突变。在这些患者的EBV-B细胞系中，存在钙和整合素结合蛋白1（CIB 1）蛋白表达的缺失。CIB 1缺陷型患者表现出典型的EV形式。因此，我们的发现是令人惊讶的，因为CIB 1是普遍表达的，并且其众多已知功能中没有一个与针对EV-HPV的免疫有关。缺乏CIB 1的小鼠表现出血栓形成、血管生成和精子发生受损。我们推测CIB 1缺陷损害角质形成细胞对EV-HPV的固有免疫。我们打算测试CIB 1在健康对照和CIB 1缺陷患者的角质形成细胞和T细胞中的表达和功能。我们还将探索CIB 1和EVER之间的潜在联系。最后，我们将研究EV-HPV在对照和患者角质形成细胞中的生长。该项目具有高度创新性，但完全可行，并且已经得到了强有力的初步证据的支持。从基本的生物学观点来看，这项研究将为EV-HPV免疫机制提供相当多的见解，特别是通过澄清CIB 1在角质形成细胞中的作用，从而可能定义EV的细胞基础。从临床的角度来看，EV发病机制的解剖将为患者提供分子诊断，为家庭提供遗传咨询，并为其他HPV驱动的病理研究铺平道路。

DESCRIPTION (provided by applicant): Epidermodysplasia verruciformis (EV) is a congenital dermatosis characterized by lifelong disseminated and persistent flat wart lesions caused by beta-papillomaviruses (EV-HPVs). EV is associated with an increase in the risk of non-melanoma skin carcinomas (NMSC), but there are no other clinical signs in most patients ("typical" EV). Morbid mutations in EVER1 and EVER2 were found in 2002. These proteins are expressed in T lymphocytes, which are involved in the clearance of HPV-infected epithelial cells, and in keratinocytes, the specific target cells of EV-HPVs. EVER proteins form a complex with the zinc transporter ZnT1 to regulate the intracellular Zn distribution and to control Zn-dependent transcriptional activity. The lack of pronounced T cell phenotype and T cell-related infections in these patients suggests that the mechanisms by which EVER deficiency confers susceptibility to EV-HPVs involves keratinocytes. EVER deficiencies account for approximately 75% of reported typical EV cases. We have recently identified AR RHOH and MST1 deficiencies in patients with EV and other clinical features ("atypical" EV) due to a profound T cell deficiency. These discoveries showed that a T-cell defect can underlie persistent EV-HPV infections. In order to better understand the pathogenesis of EV, and to decipher the molecular and cellular mechanisms of immunity against EV-HPVs, we aim to identify novel genetic etiologies of EV using a hypothesis-free, genome-wide (GW) screening approach combining GW linkage (GWL) and whole-exome sequencing (WES). In our cohort of 15 kindreds, we obtained strong preliminary evidence of a novel EV-causing gene, with the identification of homozygous mutations in CIB1 in 6 patients from two Colombian kindreds and in one French patient. In these patients' EBV-B cell lines, there is a loss of expression of the calcium and integrin binding protein 1 (CIB1) protein. The CIB1-deficient patients display a typical form of EV. Our findings are therefore surprising, as CIB1 is ubiquitously expressed and none of its numerous known functions is connected with immunity against EV- HPVs. Mice lacking CIB1 display impaired thrombosis, angiogenesis, and spermatogenesis. We hypothesize that CIB1 deficiency impairs keratinocyte intrinsic immunity against EV-HPV. We intend to test the expression and function of CIB1 in both keratinocytes and T cells from healthy controls and CIB1-deficient patients. We will also explore a potential connection between CIB1 and EVER. Finally, we will study the growth of EV-HPV in control and patients' keratinocytes. The project is highly innovative yet perfectly feasible, and already supported by strong preliminary evidence. From a basic biological standpoint, this research will provide considerable insight into the mechanisms of immunity against EV-HPV, notably by clarifying the role of CIB1 in keratinocytes, thereby possibly defining the cellular basis of EV. From a clinical standpoint, the dissection of the pathogenesis of EV will provide molecular diagnoses for patients and genetic counseling for families and will pave the way for the study of other HPV-driven pathologies.