The in vivo immunomodulatory and synergistic anti-tumor activity of thymosin α1-thymopentin fusion peptide and its binding to TLR2.

In the present study, the immunomodulatory and synergistic anti-tumor activity of thymosin α1-thymopentin fusion peptide (Tα1-TP5) was investigated in vivo. In addition, the potential receptor of Tα1-TP5 was investigated by surface plasmon resonance (SPR) binding studies. It was found that Tα1-TP5 (305 μg/kg) alleviated immunosuppression induced by hydrocortisone (HC). Tα1-TP5 (305 μg/kg) combined with cyclophosphamide (CY) had a better tumor growth inhibitory effect than CY alone. Furthermore, Tα1-TP5 had a higher affinity (KD=6.84 μmol/L) to toll-like receptor 2 (TLR2) than Tα1 (K(D)=35.4 μmol/L), but its affinity was not significantly different from that of TP5. The results of our present work indicate that Tα1-TP5 can possibly be developed as a new immunomodulatory agent.