Core Insights - The article discusses the groundbreaking research on regulatory T cells (Treg cells) and their role in controlling autoimmune responses, leading to potential new therapies for autoimmune diseases and cancer [2][3]. Group 1: Discovery and Significance - In 1995, Shimon Sakaguchi discovered a previously unknown T cell type that protects against autoimmune diseases, which was later linked to the Foxp3 gene mutations causing such diseases [3]. - The findings by Mary Brunkow, Fred Ramsdell, and Shimon Sakaguchi opened new avenues for treating autoimmune diseases and cancer by targeting specific Treg cells to suppress pathogenic autoimmune responses [3]. Group 2: Recent Research Developments - On October 22, 2025, Shimon Sakaguchi's team published two papers demonstrating the successful conversion of conventional effector T cells into stable regulatory T cells (S/F-iTreg cells) for treating inflammatory and autoimmune diseases [4]. - The first paper focuses on generating functionally stable and antigen-specific Treg cells from effector T cells for cell therapy in inflammatory diseases [4]. Group 3: Mechanism of Action - The research team utilized CDK8/19 kinase inhibitors to enhance Foxp3 expression in Tconv cells under specific stimulation conditions, establishing epigenetic changes that promote Treg characteristics [6]. - By reprogramming effector/memory CD4+ Tconv cells, including TH1, TH2, and TH17 subsets, into Foxp3+ Treg cells, the study achieved a stable and functional Treg cell population [7]. Group 4: Clinical Implications - The induced Treg cells effectively suppressed inflammatory bowel disease (IBD) and graft-versus-host disease (GvHD) in mouse models, suggesting a new strategy for antigen-specific immunotherapy [8]. - The second paper demonstrated the conversion of pathogenic T cells into stable Treg cells for treating pemphigus vulgaris, a skin autoimmune disease, providing proof of concept for clinical applications [9].