Merck Center for Catalysis at Princeton University, Princeton, New Jersey 08544, United States.
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.
J Am Chem Soc. 2024 Nov 27;146(47):32255-32262. doi: 10.1021/jacs.4c11058. Epub 2024 Nov 12.
Phagocytosis is usually carried out by professional phagocytic cells in the context of pathogen response or wound healing. The transient surface proteins that regulate phagocytosis pose a challenging proteomics target; knowledge thereof could lead to new therapeutic insights. Herein, we describe a novel photocatalytic proximity labeling method: "μMap-Interface", allowing for spatiotemporal mapping of phagocytosis. Utilizing photocatalyst-conjugated IGG-opsonized beads and initiating phagocytosis in a synchronized manner, we capture phagocytic interactome "snapshots" at the interface of the phagocyte and its target. This allows profiling of the dynamic surface proteome of human macrophages during the engulfment process. We reveal previously known phagocytic mediators as well as potential novel interactors and validate their presence with super-resolution microscopy. This includes F11R, an important cancer target yet to be investigated in the context of phagocytosis. Further, we demonstrate that knocking down F11R leads to an increased degree of phagocytosis; this insight could contribute to explaining its oncogenic activity. Lastly, we show capture of orthogonal phagocytic surfaceomes across different cells, using a neutrophil-like model. We believe this method will enable new insights into phagocytic processes in a variety of contexts.
吞噬作用通常在病原体反应或伤口愈合的情况下由专业的吞噬细胞进行。调节吞噬作用的瞬态表面蛋白是一个具有挑战性的蛋白质组学靶标；对其的了解可能会带来新的治疗见解。在此，我们描述了一种新的光催化邻近标记方法：“μMap-Interface”，可实现吞噬作用的时空图谱。我们利用光催化剂偶联的 IgG 调理珠并同步启动吞噬作用，在吞噬细胞及其靶标界面处捕获吞噬作用相互作用组的“快照”。这允许在吞噬过程中对人巨噬细胞的动态表面蛋白质组进行分析。我们揭示了先前已知的吞噬介质以及潜在的新相互作用物，并通过超分辨率显微镜验证了它们的存在。其中包括 F11R，这是一个重要的癌症靶点，但尚未在吞噬作用的背景下进行研究。此外，我们证明敲低 F11R 会导致吞噬作用程度增加；这一见解有助于解释其致癌活性。最后，我们展示了使用类似于中性粒细胞的模型在不同细胞中捕获正交吞噬表面组。我们相信这种方法将能够在各种情况下深入了解吞噬作用过程。
