Mechanisms of Papillomavirus Neutralization

乳头瘤病毒中和机制

基本信息

批准号：
8998930
负责人：
Richard Bruce Roden
金额：
$ 29.16万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-07-19 至 2019-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8998930
关键词：
Accounting Adenoviruses Affinity Alzheimer&apos s Disease Amyloid beta-Protein Precursor Animal Model Anogenital cancer Anogenital venereal warts Antibodies Antigens Antiviral Agents Binding Biotechnology Cancer Etiology Cell Nucleus Cells Cervical Cessation of life Cleaved cell Collaborations Cytoplasm Developing Countries Disease Epidermodysplasia Verruciformis Epitopes Escherichia coli Exhibits Fc Receptor Funding Genome Goals HIV Head and Neck Cancer Health Health Care Costs Hour Human Papilloma Virus Vaccine Human Papillomavirus Human papilloma virus infection Immune Immunoglobulin G In Vitro India Infection L2 viral capsid protein Licensing Link Low Income Population Low risk HPV Malignant Neoplasms Malignant neoplasm of cervix uteri Mediating Membrane Membrane Proteins Minor Morbidity - disease rate Normal Cell Oncogenic Papillomavirus Patients Play Price Proteolysis Role Senile Plaques Side Signal Transduction Site Skin Skin Carcinoma Sum Testing Transmembrane Domain Ubiquitination Vaccination Vaccine Antigen Vaccines Viral Viral Genome Virus Virus-like particle Woman base cost extracellular gamma secretase high risk inhibitor/antagonist late endosome neurotoxic neutralizing antibody prevent prophylactic secretase trafficking uptake

项目摘要

DESCRIPTION (provided by applicant): Our overall goal is to understand how L2-specific antibodies effect broad protection against HPV infection. Here, we dissect why L2 and intra-membranous cleavage by gamma-secretase are required for infection, and how antibodies to L2 potently protect by neutralization at multiple steps during infection. In the initial funding perio we made the surprising observation that gamma-secretase is absolutely required for infection by HPV (Karanam et al., 2010), but only once HPV has begun to disassemble in the late endosome and gamma-secretase's proteolytic activity is required for escape from late endosomes of L2 in association with the viral genome. Recent findings suggest that L2 has a transmembrane-like domain between residues 45-67 that is essential for infection. We propose that the putative transmembrane region pierces the endosomal membrane, and gamma-secretase cleavage releases L2's carboxy terminus to bring the viral genome to the nucleus. Two key neutralizing epitopes in L2 reside either side of L2's putative transmembrane domain. Addition of L2 antibodies even several hours after the binding of virus to cells is neutralizing, suggesting blockade occurs late in infection. Therefore, we propose: Hypothesis 1: cleavage of L2 within its putative transmembrane region by gamma-secretase is critical for endosomal escape and is inhibited by L2-specific neutralizing antibodies. Specific Aim 1A: To determine the residues of L2 required for membrane insertion and whether they contribute to infectivity by facilitating endosomal escape. Specific Aim 1B: To determine the functional role and site of gamma secretase cleavage during HPV infection and the impact of L2-specific neutralizing antibodies and gamma secretase inhibitors on endosomal escape. Antibodies have generally been assumed to effect protection in a purely extracellular manner, as they are not generally found in the cytoplasm. Recently however, a TRIM21-dependent mechanism of antibody- dependent intracellular neutralization (ADIN) has been described. TRIM21 is a cytoplasmic high affinity Fc- receptor for the Fc of virally-associated antibody in the cytoplasm, triggering degradation of the antibody-bound virus. Our new findings suggest that ADIN may be important last line of defense in protection mediated by L2 antibodies. Hypothesis 2: the Fc-region of L2-specific neutralizing antibodies is important for mediating antibody- dependent intracellular neutralization (ADIN) and protection against papillomavirus challenge. Specific Aim 2A: To determine whether binding of the Fc of L2-specific antibodies to TRIM21 contributes to antibody-dependent intracellular neutralization and if this is restricted to particular epitopes. Specific Aim 2B: To determine the contribution of TRIM21 to protection by HPV vaccination.

描述（由申请人提供）：我们的总体目标是了解 L2 特异性抗体如何对 HPV 感染发挥广泛的保护作用。在这里，我们剖析了为什么感染需要 L2 和γ-分泌酶的膜内裂解，以及 L2 抗体如何通过感染过程中多个步骤的中和来有效提供保护。在最初的资助期间，我们做出了令人惊讶的观察，即 HPV 感染绝对需要 γ 分泌酶（Karanam 等，2010），但只有当 HPV 开始在晚期内体中分解时，才需要 γ 分泌酶的蛋白水解活性。用于逃离与病毒基因组相关的 L2 晚期内体。最近的研究结果表明，L2 在残基 45-67 之间具有一个对于感染至关重要的跨膜结构域。我们认为假定的跨膜区域刺穿内体膜，γ-分泌酶裂解释放L2的羧基末端，将病毒基因组带到细胞核。 L2 中的两个关键中和表位位于 L2 推定跨膜结构域的两侧。即使在病毒与细胞结合数小时后仍添加 L2 抗体，这表明阻断发生在感染后期。因此，我们提出：假设 1：γ-分泌酶在其假定的跨膜区域内对 L2 进行裂解对于内体逃逸至关重要，并被 L2 特异性中和抗体抑制。具体目标 1A：确定膜插入所需的 L2 残基以及它们是否通过促进内体逃逸来促进感染性。具体目标 1B：确定 HPV 感染期间 γ 分泌酶裂解的功能作用和位点，以及 L2 特异性中和抗体和 γ 分泌酶抑制剂对内体逃逸的影响。通常认为抗体以纯粹的细胞外方式发挥保护作用，因为它们通常不存在于细胞质中。然而，最近描述了抗体依赖性细胞内中和(ADIN)的TRIM21依赖性机制。 TRIM21 是细胞质中病毒相关抗体 Fc 的高亲和力 Fc 受体，触发抗体结合病毒的降解。我们的新发现表明，ADIN 可能是 L2 抗体介导的保护中重要的最后一道防线。假设 2：L2 特异性中和抗体的 Fc 区对于介导抗体依赖性细胞内中和 (ADIN) 和防止乳头瘤病毒攻击很重要。具体目标 2A：确定 L2 特异性抗体的 Fc 与 TRIM21 的结合是否有助于抗体依赖性细胞内中和，以及这是否仅限于特定表位。具体目标 2B：确定 TRIM21 对 HPV 疫苗接种保护的贡献。