The Opioidergic System of Immune Cells: A New Pharmacological Target in the Therapy of “Cytokine Storm”

Abstract

This article proposes a new pharmacological approach to suppressing “cytokine storm” syndromes based on the use of opioid peptides. Immune cells possess a complete opioid signaling system consisting of all three types of opioid receptors: mu (μ), delta (δ) and kappa (κ). These cells also express proopiomelanocortin, proenkephalin and prodinorphin, which serve as precursors for such receptor agonists as β-endorphin, methenkephalin and dynorphins, respectively. A distinct feature of the opioid system of immunocytes consists in an increased expression of all its components in response to the action of cytokines and inflammation, which indicates participation of this system in regulating the immune response. It has been recently shown that dynorphins are likely to play an important role in inhibiting the expression of proinflammatory cytokines by immune cells through impeding the translocation of the active nuclear factor kappa B (NF-κB) dimer. Given the key role of the canonical pathway of NF-κB activation in cytokine expression realized when activating a variety of receptors, suppression of this pathway using opioid peptides provides a new pharmacological approach to solving the “cytokine storm” problem. The relevance of this approach is associated with the COVID-19 coronavirus infection pandemic, the role of the “cytokine storm” in which has been established by numerous studies.