Researchers made a version of thymosin‑alpha‑1 that’s attached to an antibody fragment, which makes it stay in the blood about 13 times longer (around 25 hours) than the regular peptide. In mouse studies this longer‑acting form boosted immune cell numbers and helped repair immune damage, and it also slowed the growth of melanoma and breast‑cancer tumors by ramping up immune signals like IFN‑γ and IL‑2. The work shows the concept works, but the modified protein isn’t available yet, so it’s more a proof‑of‑concept than a ready‑to‑use hack.

Thymosin alpha 1 (Tα1) is a biological response modifier that has been introduced into markets for treating several diseases. Given the short serum half-life of Tα1 and the rapid development of Fc fusion proteins, we used genetic engineering method to construct the recombinant plasmid to express Tα1-Fc (Fc domain of human IgG4) fusion protein. A single-factor experiment was performed with different inducers of varying concentrations for different times to get the optimal condition of induced expression. Pure proteins higher than 90.3% were obtained by using 5 mM lactose for 4 h with a final production about 160.4 mg/L. The in vivo serum half-life of Tα1-Fc is 25 h, almost 13 times longer than Tα1 in mice models. Also, the long-acting protein has a stronger activity in repairing immune injury through increasing number of lymphocytes. Tα1-Fc displayed a more effective antitumor activity in the 4T1 and B16F10 tumor xenograft models by upregulating CD86 expression, secreting IFN-γ and IL-2, and increasing the number of tumor-infiltrating CD4+ T and CD8+ T cells. Our study on the novel modified Tα1 with the Fc segment provides valuable information for the development of new immunotherapy in cancer.