Identification of IFN-beta therapy related biomarkers in CD4+ T cells of multiple sclerosis patients

Multiple sclerosis (MS) is neurodegenerative disease characterized by autoimmune demyelination of the central nervous system (CNS). Human interferon-β (IFN-β) treatment is generally used for relapsing-remitting form of MS (RRMS). Nevertheless, IFN-β does not show expected effects in some MS patients. This study aims to identify specific biomarkers related with IFN-β therapy. Forty-two RRMS patients (32 female, 10 male) were included in the study according to the McDonald 2017 criteria. These patients did not take any immunoregulatory drugs for at least three months and their EDSS score was below two point five. Patients were separated into two groups as female and male. After obtaining the blood samples from each patient, CD4+ T cells were isolated. CD4+ CD25+ regulatory T cells (Treg cells) were isolated from CD4+ T cells populations by fluorescence-activated cell sorting system (FACS). Cytotoxicity assays were performed to optimize drug concentrations which can affect viability of cell. Treg and CD4+ T cells treated with optimum drug concentration and control cells with no drug supplementation were used for investigation of IL-6, IL-10, IL-17, IL-23 and FOXP3 gene expressions by using Real-Time Polymerase Chain Reaction (RT-PCR). At the end of the study, it was observed that FOXP3 gene expression level was found to decrease approximately one point seven fold after 16 hours drug treatment in CD4+ T cells. In Treg cells, FOXP3 gene expression levels were observed to increase depending on time. The IL-10 gene expression levels were found lower in Treg cells in comparison to the control group as a response to drug administration in depending on time (p<0.0001). The results of our study show that FOXP3 and IL-10 genes could be used as biomarkers for CD25 + T cells. It is thought that the results obtained from this study may help to develop a personalized treatment method in the future.