Mapping tumor specific immunopeptidome for antibody-based targeted therapy

项目摘要 基于抗体的免疫疗法已经成为治疗癌症的既定范例。只有一小部分 然而，部分患者已经从这些药物中受益，而且许多患者只对一小部分有效。 肿瘤的症状。这在一定程度上是由于缺乏经过验证的细胞表面靶标。只有十几种表面蛋白具有 已被批准用于抗体干预，而且大多数并不是真正对恶性细胞独有的。已经有了 在细胞免疫多肽中寻找肿瘤专属靶点的兴趣日益浓厚。这个 免疫肽是由细胞内蛋白质的蛋白分解产生的多肽池，并展示在 细胞表面与人类白细胞抗原(人类白细胞抗原)形成复合体。据认为，这一多肽谱系 反映细胞内蛋白质组的状态，并可受癌基因的调节。包含多个表位 已经从肿瘤样本中检测到驱动突变，或新抗原，作为多肽-人类白细胞抗原复合体(Phlas)。 然而，癌基因信号如何塑造免疫表位的机制仍不清楚。 这项提议的目标是开发技术来绘制独一无二的免疫表位的变化。 特定的癌基因，以及对它们进行免疫反应的工具。这些发现最终将有助于 开发基于抗体的生物制品，具有更好的安全性和更适用于各种类型的癌症。 在这里，我们假设增殖性癌基因通过转录改变免疫表位。 重塑和选择性剪接，并诱导亲本突变片段以外的独特Phlas 癌蛋白。为了验证这一假设，我们将首先开发一种新的质谱学技术来绘制疾病地图 以一种等位基因特异的方式表达免疫多肽。接下来，我们将把这项技术与简化论细胞相结合 研究过表达特定癌基因的等基因细胞系的免疫表位的模型方法。这个 免疫药理学数据将得到蛋白质数据库和转录分析的补充，以揭示关键 癌基因特异性Phlas的贡献者。总的来说，拟议的工作将提供对如何单一的 基因改变可以影响抗原提呈机制，并在细胞表面产生新的抗原。 为了建立在这些发现的基础上，我们还将设计抗体，以高亲和力识别感兴趣的Phla 和多肽专一性。这些试剂将进一步精制成嵌合抗原受体，以增强细胞毒作用 T细胞，并对显示癌基因特异性Phlas的细胞产生抗肿瘤反应。这些试剂将是 在培养的细胞和人源化的小鼠模型中进行测试。从长远来看，基本的生物学见解和抗体 拟议的研究产生的工具将支持正在进行的了解癌症的努力 为将来针对新抗原的治疗奠定了基础。

Project Summary Antibody-based immunotherapies have become an established paradigm for treating cancers. Only a small portion of patients have benefited from these agents, though, and many are only effective for treating a small set of tumors. This is due, in part, to a lack of validated cell surface targets. Only a dozen of surface proteins has been approved for antibody intervention, and most are not truly exclusive to malignant cells. There has been growing interesting in searching the cellular immunopeptidome for tumor-exclusive targets. The immunopeptidome is a pool of peptides generated from proteolysis of intracellular proteins and displayed on the cell surface as a complex with the human leukocyte antigens (HLA). It is thought that this peptide repertoire reflects the status of the intracellular proteome and can be modulated by driver oncogenes. Epitopes harboring driver mutations, or neo-antigens, have been detected as peptide-HLA complexes (pHLAs) from tumor samples. However, the mechanism of how oncogene signaling shape the immunopeptidome remains uncharacterized. The goals of this proposal are to develop technologies to map changes in the immunopeptidome unique to specific ongene, and tools to mount an immune response against them. These findings will ultimately aid in developing antibody-based biologics with better safety profile and more applicable to diverse types of cancers. Here, we hypothesized that proliferative oncogenes globally alter the immunopeptidome via transcriptional remodeling and alternative splicing, and induce unique pHLAs beyond mutated fragments of parent oncoproteins. To test this hypothesis, we will first develop a new mass spectrometry technique to map diseased immunopeptidome in an allele-specific manner. Next, we will combine this technique with a reductionist cell model approach to study the immunopeptidome of isogenic cell lines overexpressing specific oncogene. The immunopeptidomics data will be complemented by protein databases and transcript analyses to reveal key contributors of oncogene-specific pHLAs. Collectively, the proposed work will provide insight to how a single genetic alteration can impact mechanisms of antigen presentation and produce neo-antigens on the cell surface. To build on these discoveries, we will also engineer antibodies to recognize pHLAs of interest with high affinity and peptide specificity. These reagents will be further elaborated into chimeric antigen receptors to arm cytotoxic T cells and mount antitumor response against cells displaying oncogene-specific pHLAs. These reagents will be tested in cultured cells, and humanized mice models. In the long term, the basic biological insights and antibody tools generated from the proposed studies will bolster ongoing efforts to understanding the cancerous immunopeptidome and lay the foundation for future therapeutics targeting neo-antigens.