T memory stem cell characteristics in autoimmune diseases and their promising therapeutic values
Pooria Fazeli, Mehdi Kalani, Maryam Hosseini
Abstract
Memory T cells are conventionally subdivided into T central memory (T CM ) and T effector memory (T EM ) cells. However, a new subset of memory T cells named T memory stem cell (T SCM ) cells has been recognized that possesses capabilities of both T CM and T EM cells including lymphoid homing and performing effector roles through secretion of cytokines such as interleukin-2 (IL-2) and interferon-gamma (IFN-γ). The T SCM subset has some biological properties including stemness, antigen independency, high proliferative potential, signaling pathway and lipid metabolism. On the other hand, memory T cells are considered one of the principal culprits in the pathogenesis of autoimmune diseases. T SCM cells are responsible for developing long-term defensive immunity against different foreign antigens, alongside tumor-associated antigens, which mainly derive from self-antigens. Hence, antigen-specific T SCM cells can produce antitumor responses that are potentially able to trigger autoimmune activities. Therefore, we reviewed recent evidence on T SCM cell functions in autoimmune disorders including type 1 diabetes, systemic lupus erythematosus, rheumatoid arthritis, acquired aplastic anemia, immune thrombocytopenia, and autoimmune uveitis. We also introduced T SCM cell lineage as an innovative prognostic biomarker and a promising therapeutic target in autoimmune settings.