Department of Biomedical Engineering, National University of Singapore, Singapore.
A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research (A*STAR), Singapore.
Lab Chip. 2022 Jun 28;22(13):2578-2589. doi: 10.1039/d2lc00018k.
As part of the body's immune response, antibodies (Abs) have the ability to neutralize pathogenic viruses to prevent infection. To screen for neutralizing Abs (nAbs) from the immune repertoire, multiple screening techniques have been developed. However, conventional methods have a trade-off between screening throughput and the ability to screen for nAbs their functional efficacy. Although droplet microfluidic platforms have the ability to bridge this disparity, the majority of such reported platforms still rely on Ab-binding assays as a proxy for function, which results in irrelevant hits. Herein, we report the multi-module Droplet-based Platform for Effective Antibody RetrievaL (DROP-PEARL) platform, which can achieve high-throughput enrichment of Ab-secreting cells (ASCs) based on the neutralizing activity of secreted nAbs against the a target virus. In this study, in-droplet Chikungunya virus (CHIKV) infection of host cells and neutralization was demonstrated sequential delivery of viruses and host cells picoinjection. In addition, we demonstrate the ability of the sorting system to accurately discriminate and isolate uninfected droplets from a mixed population of droplets at a rate of 150 000 cells per hour. As a proof of concept, a single-cell neutralization assay was performed on two populations of cells (nAb-producing and non-Ab producing cells), and up to 2.75-fold enrichment of ASCs was demonstrated. Finally, we demonstrated that DROP-PEARL is able to achieve similar enrichment for low frequency (∼2%) functional nAb-producing cells in a background of excess cells secreting irrelevant antibodies, highlighting its potential prospect as a first round enrichment platform for functional ASCs. We envision that the DROP-PEARL platform could potentially be used to accelerate the discovery of nAbs against other pathogenic viral targets, and we believe it will be a useful in the ongoing fight against biological threats.
作为人体免疫反应的一部分，抗体 (Abs) 具有中和致病性病毒以防止感染的能力。为了从免疫库中筛选中和抗体 (nAbs)，已经开发了多种筛选技术。然而，传统方法在筛选通量和筛选 nAbs 功能功效的能力之间存在权衡。尽管液滴微流控平台有能力弥合这种差距，但大多数此类报告的平台仍然依赖于 Ab 结合测定作为功能的替代物，这导致了不相关的命中。在此，我们报告了基于液滴的有效抗体回收多模块平台 (DROP-PEARL)，该平台可以基于针对目标病毒的分泌 nAbs 的中和活性，实现 Ab 分泌细胞 (ASC) 的高通量富集。在这项研究中，通过在液滴内感染宿主细胞和中和 Chikungunya 病毒 (CHIKV) 来证明，病毒和宿主细胞的连续传递是通过皮升级注射来实现的。此外，我们证明了该分选系统能够以 150,000 个细胞/小时的速度准确区分和分离混合群体中的未感染液滴。作为概念验证，对两种细胞群体（nAb 产生细胞和非 Ab 产生细胞）进行了单细胞中和测定，证明 ASC 的富集倍数高达 2.75 倍。最后，我们证明 DROP-PEARL 能够在过量分泌无关抗体的背景下对低频率（约 2%）功能 nAb 产生细胞进行类似的富集，突出了其作为功能 ASC 第一轮富集平台的潜在前景。我们设想 DROP-PEARL 平台有可能用于加速针对其他致病病毒靶标的 nAbs 的发现，并且我们相信它将在与生物威胁的持续斗争中发挥作用。
