Microfluidic platform for the quantitative analysis of leukocyte migration signatures

Abstract

Leukocyte migration into tissues is characteristic of inflammation. It is usually measured in vitro as the average displacement of populations of cells towards a chemokine gradient, not acknowledging other patterns of cell migration. Here, we designed and validated a microfluidic migration platform to simultaneously analyze four qualitative migration patterns: chemo-attraction, -repulsion, -kinesis and -inhibition, using single-cell quantitative metrics of direction, speed, persistence, and fraction of cells responding. We find that established chemokines C5a and IL-8 induce chemoattraction and repulsion in equal proportions, resulting in the dispersal of cells. These migration signatures are characterized by high persistence and speed and are independent of the chemokine dose or receptor expression. Furthermore, we find that twice as many T-lymphocytes migrate away than towards SDF-1 and their directional migration patterns are not persistent. Overall, our platform characterizes migratory signature responses and uncovers an avenue for precise characterization of leukocyte migration and therapeutic modulators.

Chronic allograft rejection

“…Contrary to expectations, using a single-cell visualization microfluidic model, we recently observed a process whereby these same chemokines may elicit a process of chemoinhibition [95*], and that select receptor-mediated signals and/or molecules dictate directionality of an individual leukocyte migration response [95*]. It is entirely possible that there are population-based leukocyte responses, but this study indicates that individual leukocytes may migrate in opposite directions in response to an identical chemokinetic gradient.…”

Increasing Tumor-Infiltrating T Cells through Inhibition of CXCL12 with NOX-A12 Synergizes with PD-1 Blockade

“…Of note, NOX-A12 did not alter the spheroid composition of cell types, as we have not observed any toxicity or viability decrease of tumor, stroma, or immune cells in the presence of high NOX-A12 concentrations in vitro. The eventual decrease of immune cell infiltration could thus be explained by the nonlinear effects of CXCL12, which attracts T cells at low to intermediate concentrations but repels them at high concentrations (22)(23)(24). We therefore hypothesize that by partially neutralizing CXCL12 in the outer areas, NOX-A12 generates a CXCL12 gradient within the spheroid which immune cells can follow, whereas at high NOX-A12 concentrations, all CXCL12 is blocked and therefore less migration occurs.…”

A dual-docking microfluidic cell migration assay (D2-Chip) for testing neutrophil chemotaxis and the memory effect

“…Confining cells to microchannels has the added advantage of allowing for more precise measurements of chemotaxis parameters. Similar strategies to control cell position or gradient generation for microfluidic cell migration experiments have been reported previously [47][48][49] . Our results support the biased random walk as one possible model for describing neutrophil chemotaxis and demonstrate the chemotactic memory effect.…”