Cloning and expression of soluble B lymphocyte stimulator

AIM: To clone and express soluble B lymphocyte stimulator (sBLyS). METHODS: Total RNA was isolated from peripheral blood mononuclear cells, and used to synthesize cDNA by reverse transcription. sBLyS cDNA was amplified by PCR with specific primers and inserted into a prokaryotic expression vector pET-30a. Recombinant plasmid was transformed into E.coli strain BL21(DE3). sBLyS was expressed in E.coli, purified in vitro, and analyzed with peptide mass fingerprinting and Daudi cell proliferation assay. RESULTS: sBLyS cDNA was cloned. Peptide mass fingerprinting of purified BLyS matched with that of BLyS proteins. Purified sBLyS could stimulate Daudi cell proliferation in vitro. CONCLUSION: sBLyS with biological activity was successfully expressed and purified.