Activation of NF-kB by Human Papillomaviruses

描述（由申请人提供）：感染人乳头瘤病毒（HPV）的一个子集是宫颈癌的主要危险因素。HPV E6和E7病毒基因在大多数宫颈癌细胞中选择性保留和表达，激活DNA合成并干扰多种调控途径。我们发现，人宫颈上皮细胞中HPV-16 E6和E7基因的表达可激活转录因子NF-kB，并刺激多种已知对nf - kappab敏感的基因的表达。这一点很重要，因为NF-kB是炎症和先天免疫反应的关键介质。NF-kappaB通过激活促进细胞生长和存活的基因来刺激宿主对应激的反应，NF-kappaB的组成性激活有助于恶性发展。我们假设NF-kappaB的激活为宫颈上皮细胞提供了选择性生存优势，并代表了HPV永生化的重要一步。提出的工作将解决2个相关问题：1)特定的HPV基因如何激活人宫颈上皮细胞中的NF-kB ？2) HPV感染的宫颈细胞NF-kappaB活化是否能增强HPV的永活？上皮细胞将从大多数癌症起源的宫颈转化区培养，并转染高风险，中度风险或低风险的HPV基因组或特定的HPV- 16基因。NF-kappaB的激活将通过报告基因检测来确定。宫颈细胞也将与HPV-16 E6/E7加显性阴性NF-kB突变体或野生型p65共转染，以检查NF-kappaB激活的改变是否影响永生化。我们的结果将阐明NF-kB是否是治疗HPV感染或宫颈发育不良的潜在靶点。上皮细胞参与生殖道的先天免疫，NF-kappaB是炎症和先天免疫反应的中枢调节因子。因此，我们的结果也将为HPV如何改变宿主对感染的反应提供基本信息。

DESCRIPTION (provided by applicant): Infection with a subset of human papillomaviruses (HPV) is the major risk factor for cervical cancer. The HPV E6 and E7 viral genes are selectively retained and expressed in most cervical cancer cells where they activate DNA synthesis and interfere with multiple regulatory pathways. We have found that expression of HPV-16 E6 and E7 genes in epithelial cells cultured from human cervix activates the transcription factor NF-kB and stimulates expression of multiple genes known to be NF-kappaB-responsive. This is important because NF-kB is a key mediator of the inflammatory and innate immune responses. NF-kappaB stimulates the host response to stress by activating genes that promote cell growth and survival, and constitutive activation of NF-kappaB contributes to malignant development. We hypothesize that activation of NF-kappaB provides cervical epithelial cells with a selective survival advantage and represents an important step in immortalization by HPV. The proposed work will address 2 related questions: 1) How do specific HPV genes activate NF-kB in human cervical epithelial cells? 2) Does NF-kappaB activation in HPV-infected cervical cells enhance immortalization by HPV? Epithelial cells will be cultured from the cervical transformation zone, where most cancers originate, and transfected with high risk, moderate risk, or low risk HPV genomes, or specific HPV- 16 genes. NF-kappaB activation will be determined using a reporter gene assay. Cervical cells will also be co-transfected with HPV-16 E6/E7 plus dominant negative NF-kB mutants or wild type p65 to examine whether alterations in NF-kappaB activation influence immortalization. Our results will clarify whether NF-kB is a potential target for therapy of HPV infection or cervical dysplasia. Epithelial cells contribute to innate immunity in the reproductive tract, and NF-kappaB is a central regulator of the inflammatory and innate immune responses. Therefore, our results will also provide basic information on how HPV might alter host response to infection.