Department of Medicinal and Organic Chemistry, Excellence Research Unit of "Chemistry Applied to Biomedicine and the Environment", Faculty of Pharmacy, University of Granada, Campus Cartuja, 18071 Granada, Spain.
GENYO, Pfizer-University of Granada-Junta de Andalucia Centre for Genomics and Oncological Research, P.T. Ciencias de la Salud 114, 18016 Granada, Spain.
Anal Chem. 2021 Jan 19;93(2):657-664. doi: 10.1021/acs.analchem.0c03560. Epub 2020 Dec 15.
Mass cytometry is a highly multiparametric proteomic technology that allows the measurement and quantification of nearly 50 markers with single-cell resolution. Mass cytometry reagents are probes tagged with metal isotopes of defined mass and act as reporters. Metals are detected using inductively coupled plasma time-of-flight mass spectrometry (ICP-TOF-MS). Many different types of mass-tag reagents have been developed to afford myriad applications. We have classified these compounds into polymer-based mass-tag reagents, nonpolymer-based mass-tag reagents, and inorganic nanoparticles. Metal-chelating polymers (MCPs) are widely used to profile and quantify cellular biomarkers; however, both the range of metals that can be detected and the metal signals have to be improved. Several strategies such as the inclusion of chelating agents or highly branched polymers may overcome these issues. Biocompatible materials such as polystyrene and inorganic nanoparticles are also of profound interest in mass cytometry. While polystyrene allows the inclusion of a wide variety of metals, the high metal content of inorganic nanoparticles offers an excellent opportunity to increase the signal from the metals to detect low-abundance biomarkers. Nonpolymer-based mass-tag reagents offer multiple applications: cell detection, cell cycle property determination, biomarker detection, and mass-tag cellular barcoding (MCB). Recent developments have been achieved in live cell barcoding by targeting proteins (CD45, b2m, and CD298), by using small and nonpolar probes or by ratiometric barcoding. From this perspective, the principal applications, strengths, and shortcomings of mass-tag reagents are highlighted, summarized, and discussed, with special emphasis on mass-tag reagents for MCB. Thereafter, the future perspectives of mass-tag reagents are discussed considering the current state-of-the-art technologies.
质谱流式细胞术是一种高度多参数的蛋白质组学技术，可实现近 50 种标志物的单细胞分辨率测量和定量。质谱流式细胞术试剂是带有定义质量的金属同位素标记的探针，可作为报告分子。金属通过电感耦合等离子体质谱飞行时间（ICP-TOF-MS）检测。已经开发出许多不同类型的质量标记试剂，以实现各种应用。我们将这些化合物分为基于聚合物的质量标记试剂、非聚合物的质量标记试剂和无机纳米颗粒。金属螯合聚合物（MCP）广泛用于分析和定量细胞生物标志物；然而，可检测的金属种类和金属信号都需要改进。几种策略，如包含螯合剂或高度支化聚合物，可能会克服这些问题。生物相容性材料，如聚苯乙烯和无机纳米颗粒，在质谱流式细胞术中也具有深远的意义。虽然聚苯乙烯可以包含各种金属，但无机纳米颗粒的高金属含量为提高金属信号提供了极好的机会，以检测低丰度的生物标志物。非聚合物的质量标记试剂具有多种应用：细胞检测、细胞周期特性测定、生物标志物检测和质量标记细胞条码化（MCB）。通过靶向蛋白质（CD45、b2m 和 CD298）、使用小而非极性探针或比率条码化，在活细胞条码化方面取得了新的进展。从这个角度出发，重点介绍、总结和讨论了质量标记试剂的主要应用、优势和缺点，并特别强调了 MCB 的质量标记试剂。此后，考虑到当前的技术现状，讨论了质量标记试剂的未来展望。
