Effects of Boron compounds on treg and Th17 cell population in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE)

Aim: Boron components are known to have anti-inflammatory and immunomodulatory effects. Many animal and human studies indicate that Boric Acid (BA) and Calcium Fructoborate (CaF) have effects on helper T cells in autoimmunity. The aim of our study is to evaluate effects of BA and CaF on Treg (CD4+Foxp3+) and Th17 (CD4+Ror-γt+) cell populations and related cytokine levels in mononuclear cells isolated from peripheral blood samples of Rheumatoid Arthritis (RA) and Systemic Lupus Erythematosus (SLE) patients. Methods: Newly diagnosed SLE (n=5), RA (n=10) patients and healthy individuals (n=9) were included in our study. Volunteers were divided into three groups: SK (Healthy Control) Group, SLE Group, RA Group. Consent forms were obtained from all individuals participating in the study, and blood samples were taken and peripheral blood mononuclear cells (PBMC) were isolated. Isolated cells were exposed to low dose (100 µM BA and 250 µM CaF) and high dose (1000 µM BA and 2500 µM CaF) BA and CaF in cell culture. Treg and Th17 cell populations were analyzed by flow cytometry after 48 hours of exposure. IL-2, IL-6, IL-17, IL-23, TNF-α and TGF-β levels in the culture medium were tested by ELISA method. Results: At the end of the study, high-dose BA increased the Treg population. BA showed a reducing effect on Th17 (CD4+Ror-γt+) cell population in healthy individuals. However, both BA and CaF at different doses showed an increasing effect on the inflammatory helper T Cell Th17 population in PBMCs isolated. In healthy controls high dose BA improved the Treg/Th17 population but couldn't display similar effect on RA and SLE group. Different doses of BA and CaF treatment had a variable effect on cytokine network. Conclusion: BA and CaF can affect CD4+ T helper cell differentiation in autoimmune diseases by affecting both Foxp3 and Ror-γt levels. Our primary results showed that BA and CaF could be beneficial in treatment of autoimmune disease by reducing the TNF-α levels.