A Fully Synthetic Carbohydrate-based Cancer Vaccine

描述（由申请方提供）：低聚糖如Globo-H、LewisY、Tn和STn的过表达是致癌转化细胞的共同特征。利用这种异常糖基化用于癌症疫苗开发的努力由于难以引发针对肿瘤相关碳水化合物与载体蛋白的经典缀合物的高滴度IgG抗体而变得复杂。我们已经设计、化学合成和免疫学评估了许多全合成的候选疫苗，以建立克服肿瘤相关碳水化合物和糖肽的免疫原性差的策略。我们已经发现，由TLR 2激动剂、混杂肽T辅助表位和肿瘤相关糖肽组成的三组分疫苗可以在小鼠中引发异常高滴度的IgG抗体，所述IgG抗体可以识别表达肿瘤相关碳水化合物的癌细胞。候选疫苗的上级特性归因于细胞因子的局部产生、共刺激蛋白的上调、巨噬细胞和树突细胞的增强摄取以及避免表位抑制。竞争性更新的一个重要目的是通过检查各种内置佐剂，采用外源和MUC 1衍生的辅助T表位并使用复杂性增加的碳水化合物来进一步开发完全合成的多组分疫苗候选物。我们的中心假设是，这些参数关键地调节体液和细胞免疫应答，并且只能通过详细的结构-活性关系研究来优化。此外，通过研究糖基化对MHC-I和MHC-II的细胞内运输、加工和呈递（糖）肽的影响，我们希望建立基于多组分（糖）肽的疫苗的一般设计原则。在完成拟议的研究时，我们预计将为I/II期临床试验奠定坚实的基础。我们还将采用多组分免疫原技术来产生针对MUC 1的各种糖型的糖肽特异性单克隆抗体（MAbs），我们期望利用该抗体来确定肿瘤组织表达的糖型。在这方面，缺乏针对MUC 1重要表位的充分表征的糖肽特异性MAb。然而，未来的个性化免疫治疗需要此类试剂，其中多组分癌症疫苗的糖部分的结构根据癌组织的糖表达进行定制。此外，明确定义的MAb也是基础癌症研究所需的，例如，在用于疫苗评估的动物模型中评估碳水化合物表达所需的。最后，我们将开发一套无铜点击试剂，用于癌症标志物发现和研究合成抗原的处理。 公共卫生相关性：肿瘤进展与细胞表面出现异常碳水化合物密切相关。尽管已经认识到这种异常表达可以用于癌症疫苗设计，但基于碳水化合物的癌症疫苗开发由于难以在大多数患者中引发强烈的免疫应答而变得复杂。我们正在开发全合成的多组分候选疫苗，这些疫苗可以克服肿瘤相关碳水化合物的免疫原性差，并为用于癌症免疫治疗提供前景。

DESCRIPTION (provided by applicant): The over-expression of oligosaccharides such as Globo-H, LewisY, Tn and STn is a common feature of oncogenic transformed cells. Endeavors to exploit this aberrant glycosylation for cancer vaccine development has been complicated by difficulties of eliciting high titers of IgG antibodies against classical conjugates of tumor-associated carbohydrates to carrier proteins. We have designed, chemical synthesized and immunologically evaluated a number of fully synthetic vaccine candidates to establish strategies to overcome the poor immunogenicity of tumor-associated carbohydrates and glycopeptides. We have found that a three-component vaccine composed of a TLR2 agonist, a promiscuous peptide T-helper epitope and a tumor-associated glycopeptides, can elicit in mice exceptionally high titers of IgG antibodies that can recognize cancer cells expressing the tumor-associated carbohydrate. The superior properties of the vaccine candidate are attributed to the local production of cytokines, upregulation of co-stimulatory proteins, enhanced uptake by macrophages and dendritic cells, and avoidance of epitope suppression. An important aim of the competitive renewal is to further develop the fully synthetic multi-component vaccine candidates by examining various in-build adjuvants, employ foreign and MUC1-derived helper T- epitopes and use carbohydrates of increasing complexity. Our central hypothesis is that these parameters critically modulate humoral and cellular immune responses and can only be optimized by detailed structure- activity relationship studies. Furthermore, by examining the influence of glycosylation on intracellular trafficking, processing and presentation of (glyco)peptides by MHC-I and MHC-II we hope to establish general design principles for multi-component (glyco)peptide-based vaccines. At the completion of the proposed studies we expected to have laid a firm foundation for a phase I/II clinical trial. We will also employ the multi-component immunogen technology for generating glycopeptide-specific monoclonal antibodies (MAbs) for various glycoforms of MUC1, which we expect to utilize to determine glycoforms expressed by tumor tissue. In this respect, there is a lack of well-characterized glycopeptide- specific MAbs for important epitopes of MUC1. Such reagents are, however, required for future personalized immuno-therapy in which the structure of the saccharide moiety of a multi-component cancer vaccine is tailored to the saccharide expression by cancerous tissue. Furthermore, well-defined MAbs are also required for basic cancer research and, for example, are needed for evaluation of carbohydrate expression in an animal model for vaccine evaluation. Finally, we will develop a suite of Cu-free click reagents for cancer marker discovery and studying processing of synthetic antigens. PUBLIC HEALTH RELEVANCE: Tumor progression is intimately associated with the appearance of unusual carbohydrates on the surface of cells. Although it has been realized that this abnormal expression can be exploited for cancer vaccine design, carbohydrate-based cancer vaccine development has been complicated by the difficulty of eliciting robust immune responses in most patients. We are developing fully synthetic multi-component vaccine candidates that can overcome the poor immunogenicity of tumor-associated carbohydrates and offer a prospect for use in cancer immune therapy.