In-vitro exposure to mercury chloride, with and without n-3 long chain polyunsaturated fatty acids, on the Th17-associated immune response in peripheral blood mononuclear cells from systemic lupus erythematosus patients.

Abstract

T_H17 cytokines are implicated in systemic lupus erythematosus (SLE) pathogenesis. Mercury is an environmental factor associated with the exacerbation of SLE pathology, potentially by regulating the Th_H17 pathway. Humans are primarily exposed to mercury from dental amalgams and fish consumption. Fish are also a rich source of the n-3 long chain polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and have been shown to reduce SLE disease symptoms. This pilot in-vitro investigation isolated peripheral blood mononuclear cells (PBMC) from SLE patients (N = 15) and healthy controls (HC, N = 15). The cells were stimulated with lipopolysaccharide (LPS) and exposed to 200 nM of mercury (II) chloride (HgCl) for 24 hr, with or without pre-exposure (24 hr) to either EPA or DHA at 100 μM each. The T_H17-associated cytokines were quantified in the PBMC supernatants. Pre-exposure to EPA resulted in significantly lower concentrations of IL-27 in supernatants of LPS-HgCl treated PBMC from SLE patients (29.58 [± 22.62] pg/mL) compared to HCs (51.63 [± 42.96] pg/mL) (p = 0.04). While DHA-LPS-HgCl had significantly lower IL-27 concentrations compared in LPS-HgCl in PBMC from SLE patients and HCs, there was no significant difference between groups. IL-27 exhibits pro/anti-inflammatory effects on the immune system. We suggest that the observed reductions in IL-27 concentrations following EPA-LPS-HgCl treatment support the protective role of n-3 PUFA in autoimmune responses.