Durable Interactions of T Cells With T Cell Receptor Stimuli in the Absence of a Stable Immunological Synapse

T cells engage in two modes of adhesive interaction with antigen presenting cells (APC) and surfaces: stable synapses and motile kinapses. While it is surmised that durable interactions observed between T cells and spatially isolated APCs involve stable synapses, in situ 3D imaging cannot resolve the mode of interaction. We have established in vitro platforms and quantitative metrics to determine cell-intrinsic modes of interaction when T cells are faced with spatially continuous or restricted stimulation. Human naive CD8 and CD4, memory CD4, and murine naive and memory CD8 T cells formed kinapses, whereas only the human memory CD8 T cells formed synapses on spatially uniform stimulatory 2D surfaces. Surprisingly, we did not observe any concordant relationship between the mode and durability of interaction exhibited by the human T cell subsets on cell-sized stimulatory spots. The human naive CD8 T cells maintain kinapses for more than three hours while persisting on the stimulatory spots for longer than their memory counterparts that maintain synapses. Thus, our results demonstrate that durable interactions do not require stable synapses.