A study of the immunological synapses and kinapses formed by CD4 T cell subsets

The immunological synapse (IS) is a structured interface between T cells and antigen‑presenting cells, but its organization varies with T cell differentiation state. This work tests the hypothesis that CD4 T cell subsets with distinct effector functions form structurally different IS. Using transfected fibroblasts, supported planar bilayers, and dendritic cells, I show that Th1 cells form classic centralized IS, while Th2 cells form multifocal synapses with dispersed TCR‑pMHC clusters and altered signaling organization. Induced regulatory T cells (iTregs) form either stable IS or motile kinapses depending on CD80 levels, and they downregulate CD80 on dendritic cells in an antigen‑specific manner. These findings demonstrate that IS architecture is subset‑specific and closely linked to effector function and regulatory activity.