T lymphocytes can be divided into CD4+ and CD8+ T cells, of which CD8+ T cells predominate in multiple sclerosis lesions.
However, the precise role of CD8+ T cells in the disease aetiology and pathogenesis is still not understood. Especially it is
unknown which antigens CD8+ T cells infiltrating the brain recognise with their diverse T cell receptors (TCR). Furthermore,
mechanisms leading to their dysregulation and brain infiltration remain to be defined. Besides conventional CD8+ T cells
carrying diverse TCRs, we and others recently discovered the presence of T cells with an invariant, very restricted TCR
repertoire in multiple sclerosis lesions. These cells are evolutionarily conserved, abundant in humans and are named due to their first discovery at sites of mucosal tissue, mucosa-associated invariant T (MAIT)
cells. We aim to define the role of conventional CD8+ T cells and MAIT cells in multiple sclerosis and to unravel, how
they are regulated and what they recognise. reAnother T cell subset likely involved in MS pathogenesis are regulatory CD4+ T cells. Their dysfunction
in multiple sclerosis leads to an insufficient inhibition of auto-aggressive T cell responses. Therefore, we aim to understand the mechanisms of their dysfunctional state. We ask, which functional pathways of suppression can be exploited as therapeutic strategy to regain tolerance in multiple sclerosis.