TCR-like antibodies for HPV-induced cancer basic research and theranostics

项目概要/摘要 靶向抗癌疗法的时代是由特异性治疗抗体的发展而迎来的。 主要在肿瘤上表达的抗原，改善了无数癌症患者的生活。电流 然而，抗体仅限于完整的细胞表面配体，如CD 20，其通常也表达于细胞表面。 在正常细胞上。然而，方法学的改进使得生产特异性抗体成为可能。 对于在主要组织相容性背景下呈递的来自肿瘤抗原或病毒癌蛋白的肽 复合物（MHC）I类蛋白（在人类中：HLA-A、-B、-C），其通常更好地限于肿瘤细胞。 这些抗体模拟T细胞受体（TCR）如何识别肽/MHC复合物（pMHC）。这些“TCR “模拟物”或mTCR抗体联合收割机将TCR的特异性与抗体的亲和力结合，允许TCR的特异性与抗体的亲和力结合。 靶向癌细胞表达的抗原，同时保留正常细胞。 然而，由于pMHC上靶表面的精确性质，mTCR Ab难以引发。的 目前最好的方法需要专门的高通量筛选以分离真正的mTCR抗体。我们 将通过提高mTCR抗体在体内产生的效率来改进这项正在开发的技术。 常规单克隆抗体设施。我们将通过设计免疫原来实现这一目标， 利用我们以前对HIV疫苗的经验，我们可以对所需的靶表位表面产生反应。 为了充分发展和展示我们的平台，我们将专注于人类引起的癌症， 乳头瘤病毒（HPV）作为模型系统。我们将产生的针对HPV的mTCR抗体将是有用的 立即用于HPV pMHC表达的基础研究，并最终作为离体和体内诊断， 用于治疗难治性疾病。虽然该项目的近期目标是开发我们的mTCR Ab平台， 使用HPV作为模型系统，我们的mTCR技术完全可推广到任何应用。 HPV感染导致约5%的人类癌症，几乎所有的宫颈癌，但也提供了良好的- 可以被mTCR抗体靶向的确定的抗原。我们计划针对HPV E6/E7癌蛋白 负责恶性肿瘤的诱导和维持。我们将验证这些mTCR抗体， 已知HPV毒株和HLA等位基因使用的HPV诱导的宫颈癌患者的大队列， FHCRC中国倡议。中国对改善晚期宫颈癌治疗的需求是 特别是，由于预防性筛查和HPV疫苗的获得有限。 该项目将提供（1）一种新的技术，用于产生针对任何所需pMHC靶标的mTCR抗体;（2） HLA-restricted HPV E6/E7抗原表位的呈递和表达模式的基础科学;（3）晶体 新的MHC/HPV肽复合物的结构;和（4）一组生物化学验证的HPV mTCR Ab 用于直接的基础科学应用和临床治疗诊断学的未来发展。

Project Summary/Abstract The era of targeted anti-cancer therapies was ushered in by the development of therapeutic antibodies specific for antigens expressed primarily on tumors, improving the lives of countless cancer patients. Current antibodies, however, are limited to intact cell surface ligands, such as CD20, which are often also expressed on normal cells. However, methodological improvements have made it possible to produce antibodies specific for peptides from tumor antigens or viral oncoproteins presented in the context of major histocompatibility complex (MHC) class I proteins (in humans: HLA-A, -B, -C), which are often better restricted to tumor cells. These antibodies mimic how T cell receptors (TCR) recognize peptide/MHC complexes (pMHCs). These “TCR mimic” or mTCR antibodies combine the specificity of a TCR with the affinity of an antibody, allowing the targeting of antigens expressed by cancerous cells, while sparing normal cells. However, mTCR Abs are difficult to elicit, because of the precise nature of the target surface on a pMHC. The best current approaches require specialized high-throughput screening to isolate true mTCR antibodies. We will improve this developing technology by increasing the efficiency that mTCR antibodies can be generated in conventional monoclonal antibody facilities. We will accomplish this by engineering immunogens to focus responses to the desired target epitope surface, drawing on our previous experience with HIV vaccines. In order to fully develop and demonstrate our platform, we will focus on cancers caused by human papillomavirus (HPV) as a model system. The mTCR antibodies against HPV we will generate will be useful immediately for basic studies of HPV pMHC expression, and eventually as ex vivo and in vivo diagnostics, and for treatment of refractory disease. While the proximate goal of this project is to develop our mTCR Ab platform using HPV as a model system, our mTCR technology is completely generalizable to any application. HPV infection causes about 5% of all human cancers, and virtually all cervical cancers, but also provides well- defined antigens that can be targeted by mTCR antibodies. We plan to target the HPV E6/E7 oncoproteins responsible for the induction and maintenance of malignancy. We will validate these mTCR antibodies in a large cohort of patients with HPV-induced cervical cancers of known HPV strain and HLA allele usage through the FHCRC China initiative. The need for improved treatments for advanced cervical cancer in China is particularly great, because of limited access to preventative screening and HPV vaccines. This project will deliver (1) a novel technology for generating mTCR Abs against any desired pMHC target; (2) basic science on the presentation and expression patterns of HLA-restricted HPV E6/E7 epitopes; (3) crystal structures of novel MHC/HPV peptide complexes; and (4) a panel of biochemically-validated HPV mTCR Abs for immediate basic science applications and future development as clinical theranostics.