The β 1 -adrenergic receptor links sympathetic nerves to T cell exhaustion.

CD8 + T cells are essential components of the immune response against viral infections and tumours, and are capable of eliminating infected and cancerous cells. However, when the antigen cannot be cleared, T cells enter a state known as exhaustion 1 . Although it is clear that chronic antigen contributes to CD8 + T cell exhaustion, less is known about how stress responses in tissues regulate T cell function. Here we show a new link between the stress-associated catecholamines and the progression of T cell exhaustion through the β 1 -adrenergic receptor ADRB1. We identify that exhausted CD8 + T cells increase ADRB1 expression and that exposure of ADRB1 + T cells to catecholamines suppresses their cytokine production and proliferation. Exhausted CD8 + T cells cluster around sympathetic nerves in an ADRB1-dependent manner. Ablation of β 1 -adrenergic signalling limits the progression of T cells towards the exhausted state in chronic infection and improves effector functions when combined with immune checkpoint blockade (ICB) in melanoma. In a pancreatic cancer model resistant to ICB, β-blockers and ICB synergize to boost CD8 + T cell responses and induce the development of tissue-resident memory-like T cells. Malignant disease is associated with increased catecholamine levels in patients 2,3 , and our results establish a connection between the sympathetic stress response, tissue innervation and T cell exhaustion. Here, we uncover a new mechanism by which blocking β-adrenergic signalling in CD8 + T cells rejuvenates anti-tumour functions.