The Role of T Cells in Post-stroke Regeneration

The interaction of the immune system with the brain is necessary for development and surveillance of the healthy brain. The influence of the adaptive immune system on several brain diseases has been described in great detail. In ischemic stroke, a growing body of evidence has demonstrated a key role for T cells in the acute phase after stroke. Pro- and anti-inflammatory T cell subpopulations impact in this early phase the inflammatory milieu and directly affect secondary lesion progression and neuronal injury. Recently, a functional role for T cells has also become more evident also in delayed neuronal (dys-)function and late-phase recovery after stroke. Here, T cells may also affect various non-immunological pathways involved in tissue repair, neuronal plasticity and functional recovery. These pleiotropic effects of T cells on mechanisms such as neurogenesis and angiogenesis suggest T cells as potential therapeutic target to modulate post-stroke regeneration. This chapter will provide a comprehensive overview of the current knowledge about the role of T cells in stroke with a particular focus on regenerative processes in the chronic phase.