Microfluidic single-cell technologies for assaying lymphocyte interactions

Many critical immunological responses are mediated by direct cell-cell interactions, and develop over multiple timescales. A mechanistic understanding of how diverse outcomes arise during these interactions entails identifying the relationships between various responses occurring at different stages by correlated measurements. Typical approaches that rely on population-wide correlations, however, reveal these connections broadly and mask the fine details of these relationships that might be discernible only at the single-cell level. This presentation describes the development and implementation of a novel microfluidic technology that allows defined generation, real-time imaging and longitudinal assay of lymphocyte interactions in controlled environments, thereby permitting direct correlative studies within each single immune cell. Using this technology, we were able to uncover qualitatively and quantitatively distinct calcium signaling patterns in single CD8 T cells and natural killer cells that underlie their differential functional outcomes. Our findings demonstrate that this new technology is well-suited for resolving the time-evolution of complex immune responses within each individual cell.