Regulation of TREG/TH17 balance by NK cells pretreated with ESTRIOL and bacterial cells in multiple sclerosis
We studied the influence of the pregnancy hormone estriol (E3) and bacterial strains on the ability of NK cells to modulate levels of T regulatory (Treg) and IL-17-producing (Th17) lymphocytes from patients with multiple sclerosis (MS) and healthy donors. NK cell phenotype and cytokine production in co-cultures with CD4+ lymphocytes was also investigated after incubation with the hormone and bacterial cells. Treatment of NK cells with these factors stimulated Treg formation and inhibited Th17 development. Within 24 h, NK cell cytotoxicity and production of IL-2 and IFN-γ were inhibited, while IL-10 secretion increased. This was accompanied by a rise in IL-6 and TNF-α. After three days, NK cells showed increased IL-10 and decreased IL-17 expression. Notably, cells from MS patients were more sensitive to this regulatory influence than those from healthy donors.
