The combination of hexagonal microfluidic devices and cell-based reporter cells allows detection of cytokine-producing cells at the single-cell level

• Published in: Sensors and actuators. B, Chemical Vol. 393; p. 134131
• Main Authors: Briones, Jonathan C., Okui, Yuga, Espulgar, Wilfred V., Park, JeongHoon, Itotagawa, Eri, Koyama, Shohei, Tamiya, Eiichi, Takamatsu, Hyota, Saito, Masato
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.10.2023
• Subjects: Cytokine; Functional assay; Microfluidics; Reporter cell; Secreted embryonic alkaline phosphatase; Reporter cell; Functional assay; Secreted embryonic alkaline phosphatase; Microfluidics; Cytokine
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2023.134131

Cytokine production analysis at the single-cell level, such as detection of type I interferon (IFN-I), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) producing cells, is beneficial in clinical diagnostics and drug discovery. In this work, we developed a microfluidic device with hexagonal microchambers capable of generating single-cell/multicellular systems, oil-droplet compartmentalization, and performing functional assays based on green fluorescent protein (GFP) expression or secreted embryonic alkaline phosphatase (SEAP) secretion for cytokine secretion detection at single-cell level. Since the droplets are stationary, cell/cell-pairs are identified, and real-time monitoring and end-point analysis can be performed. At optimized conditions, up to 60% single-cell chamber occupancy can be achieved. Cytokines such as IFN-I, TNF-α, and IL-6 secreted by human immune cells (THP1 cells, plasmacytoid dendritic cells (pDCs), T-cells, B-cells, and monocytes) can be detected at the single-cell level upon pairing with GFP and SEAP expressing Human Embryonic Kidney (HEK)− 293 reporter cells. This proof-of-concept device has the potential to evaluate single-cell behaviors and could benefit the field of single-cell cytokine secretion monitoring. •Microfluidic device with hexagonal chambers allows isolation of cell/cell-pairs.•Cell compartmentalization done via droplet formation with mineral oil injection.•Paired immune cell and HEK-293 reporter cell isolated to monitor secretion activity.•Single-cell cytokine secretion monitoring and evaluation in on-chip functional assay.•Assays based on either GFP expression or SEAP secretion for cytokine detection.