Single-Cell Resolution of T Cell Immune Responses.

Single antigen-specific B or T lymphocytes are the smallest functional units, into which an adaptive immune response can be dissected. Today, novel high-throughput technologies are providing researches with increasingly complex information on the diverse phenotypic signatures of individual lymphocytes. With a focus on T cells, we summarize here, how computational approaches are becoming increasingly important to identify the relevant developmental boundaries and connections between these high-dimensional lymphocyte states. We then describe how these insights may be further expanded by novel experimental approaches that allow to map the fate of individual T cells and their progeny in vivo and in vitro. Finally, we highlight how these experiments have uncovered a probabilistic regulatory structure of T cell immune responses and briefly discuss, how two distinct theoretical frameworks used to describe this structure may be merged to best capture single T cell behavior in computational terms.