Adrenergic receptors on T and B lymphocytes: Evidence, function, and clinical implications

Role of adrenergic receptor signalling in neuroimmune communication

Neuroimmune communication plays a crucial role in maintaining homeostasis and promptly responding to any foreign insults. Sympathetic nerve fibres are innervated into all the lymphoid organs (bone marrow, thymus, spleen, and lymph nodes) and provide a communication link between the central nervous system (CNS) and ongoing immune response in the tissue microenvironment. Neurotransmitters such as catecholamines (epinephrine and norepinephrine) bind to adrenergic receptors present on most immune and non-immune cells, establish a local neuroimmune-communication system, and help regulate the ongoing immune response. The activation of these receptors varies with the type of receptor-activated, target cell, the activation status of the cells, and timing of activation. Activating adrenergic receptors, specifically β-adrenergic signalling in immune cells leads to activation of the cAMP-PKA pathway or other non-canonical pathways. It predominantly leads to immune suppression such as inhibition of IL-2 secretion and a decrease in macrophages phagocytosis. This review discusses the expression of different adrenergic receptors in various immune cells, signalling, and how it modulates immune cell function and contributes to health and diseases. Understanding the neuroimmune communication through adrenergic receptor signalling in immune cells could help to design better strategies to control inflammation and autoimmunity.

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Primary and secondary lymphoid organs are innervated with sympathetic nerve fibres.

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Adrenergic receptor expression on immune and non-immune cells establishes a local neuroimmune communication system.

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Adrenergic receptor signalling in immune cells controls the differentiation and function of various immune cells.

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Modulating adrenergic receptor signalling with a specific agonist or antagonist also affect the immune response.

Elements toward novel therapeutic targeting of the adrenergic system

Adrenergic receptors belong to the family of the G protein coupled receptors that represent important targets in the modern pharmacotherapies. Studies on different physiological and pathophysiological properties of the adrenergic system have led to novel evidences and theories that suggest novel possible targeting of such system in a variety of pathologies and disorders, even beyond the classical known therapeutic possibilities. Herein, those advances have been illustrated with selected concepts and different examples. Furthermore, we illustrated the applications and the therapeutic implications that such findings and advances might have in the contexts of experimental pharmacology, therapeutics and clinic. We hope that the content of this work will guide researches devoted to the adrenergic aspects that combine neurosciences with pharmacology.

Taguchi approach for anti-heat stress prescription compatibility in mice spleen lymphocytes in vitro

Heat stress (HS) may induce immunosuppression as well as inhibit the proliferation of lymphocytes. This study evaluated the effects on immune function of our prescription on splenic lymphocytes under HS as well as its compatibility. The effects of four herbal extracts from Agastache rugosa, Atractylodes lancea, Cortex Phellodendri, and Gypsum Fibrosum on heat treated splenic lymphocytes were investigated and the compatibility of the prescription was also explored by using the Taguchi method. This study revealed changes in proliferation by traditional Chinese medicines of splenic lymphocytes after HS. Proliferation in the HS group was significantly lower than the control group. Under HS, the effects of higher concentrations of Agastache rugosa (100 and 200 μg/mL), Atractylodes lancea (100 and 200 μg/mL), Cortex Phellodendri (50 and 100 μg/mL) and Gypsum Fibrosum (100 and 200 μg/mL) caused a significant increase on ConA/LPS-induced proliferation of lymphocytes than lower concentrations. We, therefore, conclude that the prescription of traditional Chinese medicines may recover splenic lymphocytes from the immunosuppression induced by HS. The Taguchi design, which allows rapid and high efficiency for the selection of the best conditions for our prescription on HS-treated splenic lymphocytes, demonstrated that Agastache rugosa (200 μg/mL), Atractylodes lancea (200 μg/mL), Cortex Phellodendri (100 μg/mL) and Gypsum Fibrosum (100 μg/mL) were the optimal conditions for the prescription. The validation experiment confirmed that our composition in optimum extraction conditions enhanced effects on ConA or LPS-stimulated lymphocytes under HS. The results showed that the Taguchi optimization approach is a suitable method for optimization of the composition of prescription.