[The role of dopamine receptors in the modulation of mononuclear phagocytes in multiple sclerosis].

Objective: To investigate the role of dopamine receptor D ₁ DR and D ₂ DR in the production of cytokines interleukin-6 (IL-6) and IL-1β by monocytes and macrophages in patients with relapsing-remitting multiple sclerosis (MS).
Material and Methods: Ten patients with relapsing-remitting MS and 10 healthy subjects were examined. The level of IL-6 and IL-1β production was assessed in culture supernatants obtained from CD14 ⁺ monocytes or macrophages stimulated with interferon-γ (IFN-γ) and lipopolysaccharide (LPS). To study the role of dopamine receptors in the regulation of CD14 ⁺ monocytes or macrophages, samples of cells were incubated in the presence of specific D ₁ DR or D ₂ DR antagonists, after which IFN-γ/LPS were added to the cultures. Levels of cytokines in culture supernatants were measured by enzyme-linked immunosorbent assay.
Results: The production of IL-6 and IL-1β by CD14 ⁺ monocytes and macrophages was comparable between the groups. Blockade of D ₁ DR suppressed cytokine production by CD14 ⁺ monocytes and macrophages in both groups. In contrast, blockade of D ₂ DR increased the production of cytokines by CD14 ⁺ monocytes and did not affect cytokine production by macrophages in both groups.
Conclusions: Targeting of dopaminergic receptors could be considered as an additional mechanism of immunomodulation in MS with both pro- and anti-inflammatory effects on cells of the innate immune system.