Evaluation of PD-L1 and CTLA-4 gene expression in peripheral blood mononuclear cells of patients with multiple sclerosis treated with interferon beta1-alpha, Fingolimod, DMF and Glatiramer acetate in comparison with untreated patients in Tabriz

Abstract

Multiple sclerosis (MS) is considered as an autoimmune disease that is associated with demyelination, axonal damage and neurological disorders in the central nervous system (CNS). This disease is characterized by inflammation and usually leads to significant disorders in most patients. With the ever-increasing advances in genetic technologies, significant genetic mutations in the immune system have recently been identified. For example, immune checkpoints play an important role in maintaining the balance of the immune system. CTLA-4 and PD-L1 are inhibitory immune checkpoints involved in many autoimmune diseases, including MS. Methods: CTLA-4 and PD-L1 gene expression levels in peripheral blood mononuclear cells of MS patients were evaluated using single-cell RNA-seq data. In addition, through laboratory evaluation and using qRT-PCR, it was shown how the expression of CTLA-4 and PD-L1 changed in PBMC samples of relapsing-remitting multiple sclerosis (RRMS) patients compared to the healthy group. Finally, the effect of various MS-related treatments on CTLA-4 and PD-L1 expression was investigated. Findings: Bioinformatics results showed that 12 different cell types were identified based on specific markers between MS patients and controls. Also, CTLA-4 and PD-L1 were mainly expressed on undifferentiated T cells, regulatory T cells, and activated CD8+ T cells. Laboratory investigations showed that the expression level of PD-L1 and CTLA-4 in the control group was significantly higher compared to untreated patients. The relative expression of these two genes in patients treated with fingolimod was much higher than in patients without treatment. In addition, the group that received DMF and IFNβ-1α showed an increased expression level compared to the untreated groups. It was not statistically significant.