Nervous regulation: beta-2-adrenergic signaling in immune homeostasis, cancer immunotherapy, and autoimmune diseases.

Beta-2-adrenergic receptor (β-AR) mediates neural signaling from the sympathetic nervous system (SNS) to the immune system to modulate immunogenic and immunosuppressive responses for maintaining immune homeostasis. β-AR regulates various cellular activities on the innate and adaptive immune cells through differential signaling to modulate activation, proliferation, differentiation, and cytokine production. This signaling pathway has been found to be critical for regulating anti-tumor immune responses and autoimmune responses. Recently, β-AR has also been implicated in the mobilization of immune cells in peripheral blood and ex-vivo expansion of cytotoxic T cells from donor blood that has clinical implications for improving cancer immunotherapy. This review attempts to provide a comprehensive overview of the established and emerging roles of β-AR signaling in immune homeostasis, cancer immunotherapy, and autoimmune diseases.