As one of the major cytokines implicated in the orchestration of immune responses, interleukin 6 (IL-6) can either act as a pro- or an anti-inflammatory factor, depending on the micro-environment. In micro-immunotherapy (MI) medicines, IL-6 is employed at low doses (LD) and ultra-low doses (ULD), expressed in centesimal Hahnemannian (CH), and used alone or in combination with other immune regulators to modulate patients' immune responses. The present study focused on assessing the in vitro immune-modulatory effects of two IL-6-containing MI products: (i) the unitary IL-6 (4 CH) and (ii) the complex MI-medicine (MIM) 2LALERG®, which includes IL-6 (17 CH) in association with other actives in its formulation. Our results showed that IL-6 (4 CH) activated granulocytes under basal conditions, and natural killer cells in the presence of an anti-CD3 signal, as assessed by their CD69 expression. In addition, IL-6 (4 CH) balanced the macrophages' differentiation toward a M2a profile. On the other hand, the tested 2LALERG® capsule inhibited the histamine degranulation of rats' peritoneal mast cells and reduced the release of IL-6 itself in inflamed human macrophages. Altogether, these data provide novel pieces of evidence on the double-edged potential of the LD and ULD of IL-6 in immune responses modulation, when employed in MI.
Keywords: allergy; immune cells models; immune responses modulation; interleukin-6; low doses; micro-immunotherapy; ultra-low doses.