[Screening and identification of stable transfectants of mouse soluble B lymphocyte stimulator]

Mouse colon cancer cells CT26 were transfected with constructed plasmid expressing mouse soluble B lymphocyte stimulator (msBlyS). Single cell clones were selected with 100 microg/ml Zeosin and subcloned by serial limiting dilution. Eight resistant transfectants were isolated and expanded, and five of them displayed the desirable msBlyS cDNA band amplified by semi-quantitative RT-PCR assay. Western blot analysis showed that only msBlyS molecules of the expected size were detected in the cell lysates from transfectants. The supernatant of transfectants could costimulate B cell proliferation in standard costimulation assay. Thus we have successfully screened the stable transfectants expressing high levels of msBlyS in CT26 cells, which could be used as cancer vaccines for further anti-tumor immunotherapy.