Engineer Immune Cells via Chemoenzymatic Glycan Editing

项目总结/摘要 细胞-细胞相互作用涉及许多生物过程，包括免疫反应， 胚胎发育、神经元信号传导和癌症转移。我们在理解上的一些主要差距 细胞间的相互作用包括：什么是一个特定的细胞类型在不同阶段的相互作用伙伴， 生物过程？如何改变这些相互作用的伙伴的细胞表面景观来调节功能 一种特定的细胞类型，其内源性功能的干扰最小？ 本项目的目标是开发基于糖基转移酶的化学酶促方法， 将生物聚合物，包括酶和单克隆抗体，结合到细胞表面，以研究这些 谜题 在本项目的目标1中，我们将鉴定或设计一种混杂糖基转移酶， 将生物聚合物官能化的非天然糖从相应的核苷酸糖供体转移到细胞表面 目的细胞的糖萼。当生物聚合物是酶时，它将使得邻近依赖性聚合物能够被聚合。 标记与含有酶的感兴趣的细胞（诱饵细胞）相互作用的猎物细胞，条件是 被捕食细胞的细胞表面表达被酶修饰的底物。随后，信号 可以通过流式细胞术离体检测和分析通过标记产生的细胞。在目标1d和目标2中，我们 将使用小鼠模型将这种方法应用于体内探测细胞-细胞相互作用。重点将是 在免疫活化和T细胞免疫应答过程中识别特定免疫细胞类型的相互作用伴侣 衰竭（T细胞衰竭是T细胞逐渐失去功能的过程）。最后我们 将在目标3中开发一种方法，将单克隆抗体结合到免疫细胞上， 具体的瞄准能力。修饰细胞的迁移和抗肿瘤功效将在 小鼠肿瘤模型。

PROJECT SUMMARY/ABSTRACT Cell-cell interactions are involved in numerous biological processes, including immune responses, embryonic development, neuronal signaling and cancer metastasis. Some major gaps in our understanding of cell-cell interactions include: what are the interacting partners of a specific cell type at different stages of a biological process? How to modify the cell-surface landscape of these interacting partners to tune the functions of a specific cell type with minimum perturbation of its endogenous functions? The objective of this project is to develop glycosyltransferase-based chemoenzymatic methods to incorporate biopolymers, including enzymes and monoclonal antibodies, onto the cell surface to study these puzzles. In Aim 1 of this project, we will identify or engineer a promiscuous glycosyltransferase that can transfer biopolymer-functionalized unnatural sugars from the corresponding nucleotide sugar donors to the cell-surface glycocalyx of the cells of interest. When the bioploymer is an enzyme, it will enable the proximity-dependent labeling of prey cells that interact with the cells of interest (bait cells) that harbor the enzyme, providing that the cell surface of prey cells expresses the substrates to be modified by the enzyme. Subsequently, the signal generated by the labeling can be detected and analyzed ex vivo by flow cytometry. In Aim 1d and Aim 2, we will apply this method to probe cell-cell interactions in vivo using mouse models. The focus will be the identification of interacting partners of specific immune cell types during immune activation and T-cell exhaustion (T-cell exhaustion is the process during which T cells progressively lose their functions). Finally, we will develop a method in Aim 3 to conjugate monoclonal antibodies onto immune cells to endow them with specific targeting capabilities. The migration and anti-tumor efficacy of the modified cells will be evaluated in mouse tumor models.