🛡️Thymosin Alpha-1 (Tα1)
Thymic peptide and potent immune system modulator. FDA-approved (Zadaxin) in 37 countries for hepatitis B, hepatitis C, and immunodeficiency. Activates dendritic cells, NK cells and Th1 response.
Ac-Ser-Asp-Ala-Ala-Val-Asp-Thr-Ser-Ser-Glu-Ile-Thr-Thr-Lys-Asp-Leu-Lys-Glu-Lys-Lys-Glu-Val-Val-Glu-Glu-Ala-Glu-AsnWhat Is Thymosin Alpha-1?
Thymosin Alpha-1 (Tα1) is a naturally occurring 28-amino-acid peptide derived from prothymosin alpha in thymic tissue. It is approved in 37 countries (as Zadaxin, SciClone) for treatment of hepatitis B, hepatitis C, and immunodeficiency states. It is also under investigation for sepsis and cancer immunotherapy enhancement.
Key Mechanisms
- Dendritic cell activation — matures immature DCs and enhances antigen presentation
- Th1 polarisation — shifts immune response toward cellular immunity via IL-12 and IFN-γ production
- NK cell enhancement — increases natural killer cell cytotoxicity
- TLR-9 signalling — activates innate immune recognition pathways
- T-cell maturation — stimulates differentiation of T-cell precursors in thymus and periphery
Key References
- Garaci E et al. "Thymosin alpha1 in the treatment of cancer." Ann N Y Acad Sci, 2012;1270:26–31.
- Romani L et al. "Thymosin alpha 1 activates dendritic cell tryptophan catabolism." J Clin Invest, 2004;114:1579–1588.
Frequently Asked Questions
Marketed as Zadaxin (SciClone Pharmaceuticals) in roughly 37 countries for hepatitis B, hepatitis C, and certain immunodeficiency states — it does not currently hold FDA approval in the United States.
Despite the similar naming, they're structurally and functionally distinct — Alpha-1 is an immune-modulating peptide (dendritic cell activation, Th1 polarisation) while Beta-4/TB-500 is an actin-regulating tissue-repair peptide. They belong to different thymosin peptide families entirely.
Research has extended into sepsis, cancer-immunotherapy adjuvant use, and vaccine-response enhancement, based on its dendritic-cell and Th1-skewing mechanisms.