Chemoenzymatic glycan editing for deciphering biological functions of glycans

化学酶聚糖编辑破译聚糖的生物学功能

基本信息

批准号：
10329937
负责人：
Peng Wu
金额：
$ 76.42万
依托单位：
SCRIPPS RESEARCH INSTITUTE, THE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-02-01 至 2026-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10329937
关键词：
Affinity Autoimmune Diseases Binding Binding Proteins Biological Process Cell Communication Cell physiology Cell surface Cells Development Disease Progression Engineering Environment FDA approved Fucose Genome Glycoconjugates Glycoproteins Goals Immune Immune System Diseases Immune checkpoint inhibitor Immune signaling Immunoglobulins Immunotherapy In Situ Label Lectin Ligands Malignant Neoplasms Mediating Metabolic Methods Modality Modification Molecular Molecular Biology Techniques Monosaccharides N-acetyllactosamine Natural Killer Cells Oligosaccharides Organism Patients Polysaccharides Production Property Recombinants Role Sialic Acids Signal Transduction Specificity Structure T-Lymphocyte Therapeutic Agents Tumor Immunity Vaccination Visualization anti-CTLA4 anti-PD-1 base checkpoint inhibition cytokine cytotoxic exhaustion glycosylation glycosyltransferase human disease immune activation immunoregulation interest novel novel therapeutics receptor receptor binding response sialic acid binding Ig-like lectin sugar nucleotide tool

项目摘要

PROJECT SUMMARY/ABSTRACT Cell-surface glycans participate in numerous biological processes, including signal transduction, cell-cell communication and development. Aberrant glycosylation is a hallmark of human disease. At a molecular level, glycans represent the first points of contact between cells. However, not directly encoded in the genome, these biomolecules are challenging to study using molecular biology techniques alone. Metabolic oligosaccharide engineering (MOE) developed in late 1990’s has revolutionized the way for the labeling and visualization of glycans in living organisms. In this method, cells’ own glycan biosynthetic machinery is hijacked to incorporate unnatural monosaccharides with linkage promiscuity. Complementary to MOE, chemoenzymatic glycan editing has emerged as a valuable tool to probe and modify glycan structures within a cellular environment. Unlike MOE, chemoenzymatic glycan modification utilizes recombinant glycosyltransferases to transfer natural or unnatural monosaccharides with novel functions from activated nucleotide sugars to glycoconjugates on the cell surface with linkage specificity. For these reasons, chemoenzymatic glycan modification provides a facile and more precise way for probing the function of glycans in their native environments. Building upon our successful application of chemoenzymatic glycan editing, in the next five years we will expand our chemoenzymatic tool kits to study glycans’ cellular functions with a focus on the special roles of N- acetyllactosamine (LacNAc), fucose and sialic acid in immune regulation. Cell-surface LacNAc mediates ligand-receptor binding and sets a threshold for initiating the downstream signaling for immune cell activation. LacNAc residues are dynamically modified by sialic acid and/or fucose. However, the specific roles of these modifications in immune regulation and disease progression remain obscure. We are particularly interested in finding out: (1) if changes in LacNAc and fucosylation status can serve as glycan signatures of T cell exhaustion during which T cells gradually lose their cytokine production, proliferation and cytotoxic capacity; (2) Can cell-surface in situ LacNAc fucosylation be used to boost the efficacy of antitumor immunity of T cells and NK cells? In parallel, we will develop chemoenzymatic tools for profiling sialylated glycoprotein ligands of Siglecs (sialic acid-binding immunoglobulin-type lectins) and for the identification of unnatural, high-affinity and specific ligands to interrogate Siglec functions. Through these studies, we will gain a deeper understanding of how LacNAc, fucose and sialic acid are involved in the regulation of the immune cell activation, effector function and exhaustion. Tools developed in this project can also be used to study other types of glycans and their interactions with glycan binding proteins.

项目概要/摘要细胞表面聚糖参与许多生物过程，包括信号转导、细胞间在分子水平上，异常的糖基化是人类疾病的标志。聚糖代表细胞之间的第一个接触点，但是它们并不是直接在基因组中编码的。仅使用分子生物学技术来研究生物分子具有挑战性。 1990 年代末开发的工程 (MOE) 彻底改变了标签和可视化的方式在这种方法中，细胞自身的聚糖生物合成机制被劫持以整合。连接杂乱的非天然单糖。作为 MOE 的补充，化学酶聚糖编辑已成为探索和与 MOE 不同的是，化学酶促聚糖修饰在细胞环境中进行。利用重组糖基转移酶转移具有新功能的天然或非天然单糖从活化的核苷酸糖到细胞表面上的糖缀合物，具有连接特异性。由于化学酶聚糖修饰为探测功能提供了一种简便且更精确的方法聚糖在其天然环境中的分布。在我们成功应用化学酶聚糖编辑的基础上，未来五年我们将扩展我们的化学酶工具包来研究聚糖的细胞功能，重点关注 N- 的特殊作用乙酰乳糖胺 (LacNAc)、岩藻糖和唾液酸在细胞表面 LacNAc 介导中的作用。配体-受体结合并设置启动免疫细胞激活下游信号传导的阈值。 LacNAc 残基被唾液酸和/或岩藻糖动态修饰，然而，这些的具体作用。免疫调节和疾病进展的改变仍然不清楚。我们特别有兴趣了解：(1) LacNAc 和岩藻糖基化状态的变化是否可以起到作用作为 T 细胞衰竭的聚糖特征，在此期间 T 细胞逐渐失去细胞因子的产生，增殖和细胞毒性能力；（2）细胞表面原位 LacNAc 岩藻糖基化可用于增强细胞增殖和细胞毒性能力； T细胞和NK细胞的抗肿瘤免疫功效如何？同时，我们将开发化学酶工具分析 Siglecs（唾液酸结合免疫球蛋白型凝集素）的唾液酸化糖蛋白配体，并用于鉴定非天然、高亲和力和特异性配体以探究 Siglec 功能。通过这些研究，我们将更深入地了解LacNAc、岩藻糖和唾液酸是如何作用的。参与免疫细胞激活、效应器功能和耗竭调节的工具。该项目还可用于研究其他类型的聚糖及其与聚糖结合蛋白的相互作用。