Figure 3. Naïve CD4 T cells of MS patients have dysregulated miRNA expression which target the TGF-β signaling pathway and suppress Treg development and function.
Numerous miRNAs were found to be over-expressed in naïve CD4 T cells of MS patients that target TGF-βRI, TGF-βRII, SMAD2 and SMAD4. In contrast, 3 miRNA were down-regulated that were predicted to target SMAD7, a negative regulator of the TGF-β signaling pathway. Severin et al [78] found that these miRNAs reduced the ability of naïve CD4 T cells to differentiate into Tregs which may partially explain the Treg defect observed in MS patients.