In vitro immunomodulatory effect of Opisthorchis felineus hemozoin on dendritic cells of children with bronchial asthma

Predominance of the Th2 pathway was noted for adaptive immune response in atopic diseases. The Th2-type response is characterized by increased levels of IL-4, IL-5, IL-13, triggering humoral and cell-mediated immune responses associated with production of IgE, basophils, eosinophils and mast cells. Current research focuses on immunoregulatory potential of helminths and their excretory products, which have potential for the pharmaceutical industry. It is known that the parasite in host organism is able to evade the immune response and it may inhibit, alter and modify the current immune responses in the host by producing immunomodulatory substances. The excretory/secretory products resulting from the co-evolution of the host and parasite, may suppress the type 2 immune response, while activating type 1 and type 17 responses. The immunosuppressive microenvironment created by helminths may not only help them to evade the host immune response, but also prevent serious damage to the body caused by excessive inflammation. The role of liver fluke in reducing inflammation has been shown in allergic diseases. The excretory/secretory molecule of the liver fluke (hemozoin) is a promising product of parasitic origin which has a pronounced immunomodulatory properties: it is a dark brown insoluble biocrystal substance synthesized during the life of hematophagous parasites Rhodnius prolixus, Schistosoma mansoni, Plasmodium falciparum, Echinostoma trivolvis, Haemoproteus columbae, Clonorchis sinensisi and Plasmodium falciparum, Opisthorchis felineus. In this regard, the search for helminth-associated molecules exhibiting immunomodulatory effects with low toxicity and immunogenicity, seems to be an urgent task. The aim of the present study was to establish the effect of O. felineus hemozoin on the cytokine profile of dendritic cells (DCs) in patients with bronchial asthma. It was shown that a combined stimulation of DCs from examined patients with the D. pteronyssinus antigen and O. felineus hemozoin is associated with high levels of Th1 profile cytokines (IL-1β, IFNγ), as well as high activity of Treg cells (IL-10). Hence, the liver fluke hemozoin is able to change the cytokine profile of DCs in patients with bronchial asthma. This property of native hemozoin isolated from O. felineus may be further studied for correction of disorders associated with Th2 polarization of immune response which is a common feature of atopic diseases.