The Evaluation of Foxp3 Gene Expression in Control of T Cells Functions in MS Disease: Systematic Review

Multiple Sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system (CNS), which is more common in young adults. Disorder in tolerance mechanisms such as CD4+ CD25+ T regulatory cells (Treg) may lead to MS disease. In addition, CD8+ T cells may play a supporting role in MS, as they mediate between immunity and tolerance by the acquisition of suppressive activity. Forkhead box p3 (Foxp3) is known to confer suppressive activities in both CD4+ CD25+T cells and CD8+ T cells. We searched PubMed, Google Scholar and Cochrane library from January 2000 until January 2019. 1052 articles were found, which 962 articles were excluded by investigating topics and 81 articles by reading abstract. Finally, 9 articles included in our study. Results demonstrate that not only the Foxp3 mRNA and protein levels in CD4+CD25+ T cells are reduced in MS patients than health controls but also are lower in single-cell level, which result in reducing the suppressive function of CD4+CD25+ T cells. Moreover, there is a correlation between Foxp3 expression and CBLB mRNA , ITCH mRNA and T helper type 2 cytokine mRNA on the CD4+CD25+ T cells surface. Conversely, the Foxp3 gene is highly expressed in CD8+T cells, involved in tolerance maintenance in MS. Conclusions: The assessment of the Foxp3 gene expression could be one of the options for identification of MS disease since expression variations of this gene are obvious. In addition, The Foxp3 gene expression in CD4+CD25+ T cells can be increased bynew methods such as using MicroRNA in order to reduce the complications of this disease. The variations of Foxp3 gene expression in CD8+ T cells in MS need to be studied more, as these cells play an important role in tolerance maintenance in MS.