The role of non-neuronal acetylcholine production in immune cells

Abstract

The cholinergic system deals with the production, function, transport, and degradation of acetylcholine (ACh), a molecule commonly known as a neurotransmitter. This system has been shown to regulate inflammation via its resolution. Although increasing evidence suggests the importance of ACh in immune regulation, its role within specific immune cells remains inconclusive. Assessing the presence of cholinergic markers in immune cells in conjunction with their pharmacological inhibition will thus help to clarify the functional roles of the cholinergic system in the immune response. The aim of this study was to evaluate the role of non-neuronal ACh production in immune regulation. Expression studies using qPCR, western blots, mass spectrometry, and immunocytochemistry revealed the presence of ACh and choline acetyltransferase in immune tissues and within immune cells of such tissues. In addition, the effect of cholinergic inhibitors on immune function was examined on M1/M2 murine bone marrow derived macrophages (BMDMs) by examining their cytokine profile. Overall, inhibiting the synthesis of ACh seemed to significantly cause cell death in M1 BMDMs and non-significantly cause cell death in M2 BMDMs; yet other treatment conditions did not seem to cause cell death. However, due to pharmacological and statistical limitations, cytokine secretion profiles were generally inconclusive. These data further shed light on the role cholinergic system within immune cells, but further research would be necessary to validate these findings.