Thymosin Alpha 1 (Tα1) is a 28-amino acid peptide derived from prothymosin alpha, naturally produced by the thymus gland, and plays a central role in modulating immune function by promoting T-cell activation and enhancing the body’s ability to identify and eliminate infected or abnormal cells.
 It functions as an agonist for toll-like receptors 2 and 9 (TLR-2 and TLR-9) on myeloid and dendritic cells, stimulating both innate and adaptive immune responses through the activation of downstream signaling pathways such as NF-κB and IRF3, leading to increased production of cytokines like IL-2, IL-12, IFN-α, and IFN-γ.
 Tα1 enhances cell-mediated immunity, supports the maturation and differentiation of T-cell progenitor cells, activates natural killer cells and dendritic cells, and helps regulate inflammation by reducing levels of pro-inflammatory cytokines such as IL-1β and tumor necrosis factor-α.
 It has been clinically used to treat viral infections like hepatitis B and C, immune deficiencies, and certain cancers, and is also being explored as an adjuvant to improve vaccine responses and as a supportive therapy in severe infections including sepsis and critically ill patients.