Aim. To present the contemporary knowledge on interactions between the immune system and neuroendocrine system.
Review. On the cellular and molecular levels, mutual interactions of these homeostatic systems are based on the existence of shared receptors and their ligands: cytokines (including endogenous opioids), hormones, and neurotransmitters. The nature of functioning of both the innate immunity (with participation of phagocytes) and acquired adaptive immunity (with participation of lymphocytes) is outlined. The immune system response to antigenic stimulation is accompanied by activation of the hypothalamic-pituitary-adrenal stress axis, sympathetic nervous system, and of the endogenous opioid system. On the other hand, the immune reactions are modified by physical and psychological stressors, which results – depending on numerous additional factors –either in enhancement or inhibition of their components.