Distinct actin cytoskeleton behaviour in primary and immortalised T-cells.

Cytoskeletal actin dynamics are crucial for the activation of T-cells. Immortalised Jurkat T-cell lines have been the model system of choice to examine and correlate the dynamics of the actin cytoskeleton and the immunological synapse leading to T-cell activation. However, it has remained unclear whether the immortalised cellular systems such as Jurka T-cells can recapitulate the primary T-cells' cytoskeletal behaviour. Studies delineating the cytoskeletal behaviour of Jurkat T-cells in comparison to primary T-cells are lacking. Here, we employ live-cell super-resolution microscopy to investigate the cytoskeletal actin organisation and dynamics of living primary and immortalised Jurkat T-cells at the right spatiotemporal resolution. At comparable activation conditions, we found differences in the architectural organisation and dynamics of Jurkat and primary Mouse and Human T-cells. While the three major actin network architectures in Jurkat T-cells were reminiscent of primary T-cells, there was a difference in the organisation as well as molecular mechanisms of these networks. Our results highlight mechanistic distinctions in the most-utilised T-cell model system to study cytoskeletal actin dynamics.