Related Experiment Video
Updated: Aug 2, 2025

Author Spotlight: Achieving High-Purity In Vitro Differentiation of Th17 Cells Using Cytokine Concentration Modulation
Published on: October 25, 2024
STA-21, a small molecule STAT3 inhibitor, ameliorates experimental autoimmune encephalomyelitis by altering
Tohid Gharibi1, Nesa Barpour1, Arezoo Hosseini2
1Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Immunology, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Neurosciences and Cognition, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
Background:
Numerous studies have demonstrated the role of T helper (Th) 17 and T regulatory (reg) cells and pro-inflammatory and anti-inflammatory cytokines related to these cells in the pathogenesis of MS and its animal model, experimental autoimmune encephalomyelitis (EAE). STAT3 is one of the downstream signaling proteins of IL-23, IL-6, and IL-21 that are required for Th17 cells differentiation. STA-21 is a STAT3 inhibitor that functions by inhibiting STAT3 dimerization and binding to DNA impairing the expression of STAT3 target genes including, RORγt, IL-21 and IL-23R that are also required for Th17 cell differentiation.
Aim:
In this study, we evaluated the effect of STA-21 on EAE Model and investigated how this small molecule can change Th17/Treg balance leading to amelioration of disease.
Methods:
After EAE induction and treatment with STA-21, its effects were assessed. Major assays were H&E and LFB staining, Flow cytometric analysis, Reverse transcription-PCR (RT-PCR), and ELISA.
Results:
STA-21 ameliorated the EAE severity and decreased the EAE inflammation and demyelination. It also decreased STAT3 phosphorylation, the proportion of Th17 cells and the protein level of IL-17. In contrast, the balance of Tregs and the level of anti-inflammatory cytokine, IL-10 increased in STA-21-treated mice. Moreover, STA-21 significantly decreased the expression of Th17 related transcription factors, RORɣt and IL-23R while FOXP3 expression associated with Treg differentiation was increased.
Conclusion:
This study showed that STA-21 has therapeutic effects in EAE by reducing inflammation and shifting inflammatory immune responses to anti-inflammatory and can be used as a suitable treatment strategy for the treatment of EAE. The effectiveness of inhibiting or strengthening the functional cells of the immune system by these small molecules in terms of easy to access, simple construction and inexpensive expansion make them as a suitable tool for the treatment of inflammatory and autoimmune diseases.

