Construction and expression of a new fusion protein, thymosin alpha1-cBLyS, E. coli.

A fusion thymosin alpha1-soluble B lymphocyte stimulator (TM alpha1-cBLyS) gene was generated to engineer a bifunctional lymphokine, which was then over-produced in Escherichia coli. The molecular weight of the expressed fusion protein was approximately 28 kDa. After being purified by Ni-NTA affinity column, the fusion protein had full activity of BLyS with a slightly higher immunological action than synthetic TMalpha1. Because TM alpha1 regulates the cellular immune response and cBLyS amplifies the humoral response, this bifunctional lymphokine could be useful in the treatment of various immunodeficiency syndromes and serve as an immunomodulator to enhance the host's response to vaccination.