Dynamic live cell imaging of immune cell interactions using microfluidics cell trap

Abstract

Abstract While providing indispensable insight into immune processes, the live cell imaging of immune cells poses unique challenges due to their non-adherent nature. Suspension cells such as immune cells can easily move away from the FOV (field of view) during imaging by any physical perturbations such as introduction of agonist or even simple media change, often necessitating the use of surface coating to artificially immobilize cells. In addition, unlike adherent cells, interacting suspension cells form aggregates, making it very difficult to track and analyze individual cells during imaging. Previously, we have described the novel microfluidic-based dynamic live cell imaging platform CellASIC ONIX2, where microenvironmental parameters such as the perfusion of media/reagent, temperature, and gas compositions can be precisely controlled on demand via software during the entire imaging experiment. We now report further utility of the system with a new non-adherent cell trap culture plate comprising an array of walled ~100μm square pads with a 12μm height restriction and 3μm wall gap, allowing physical trapping of immune cells within FOV while enabling their natural movement, and preventing vertical cell stacking of aggregated cells while preserving cell-cell interactions. Using Jurkat T cells and super antigen loaded Raji B cells, we demonstrate dynamic live cell imaging of immune cell interactions. Unlike systems where cells are artificially immobilized, we show that these cells are extremely motile and behave in much more complex and dynamic fashion during their interactions. The technology should benefit live cell imaging of any suspension cells and is amendable for wider applications in addition to immune cell imaging.