Gene Construction, Expression And Biologic Activities Of RhuGM-CSF/IL-6 Fusion Protein

HuGM-CSF and huIL-6 have both synergistic action and complementary action.The fusion protein of this two cytokine maybe have more effective biological function.So,we want to construct the gene of GM-CSF/IL-6 fusion protein and obtain corresponding protein.Studies on structure and function of GM-CSF have shown that residues 1 to 13 at the N terminus are not important for rhGM-CSF activity,furthermore,they interfere GM-CSF binding to it's receptor.The ninth amino acid of GM-CSF is proline,it can resist degradation of bacterium protease if use it as the first amino acid of GM-CSF/IL-6 fusion protein. In addition,the first 28 amino acids of IL-6 could be removed without significantly affecting biologic activity. Studies have shown that removal of the first 23 amino acids resulted in an increase on activity.To obtain effective expression and fusion protein with high purity and both huGM-CSF and huIL-6 biologic activities, six novel gene sequence of GM-CSF/IL-6 fusion protein was designed.They were GM-CSF(9-127)-IL-6(29-184)( To abbreviate GI1), GM-CSF(9-127)-IL-6(1-184)( To abbreviate GI2), GM-CSF(1-127)-IL-6(1-184)( To abbreviate GI3), GM-CSF(9-127)-IL-6(24-184)( To abbreviate GI4), IL-6(1-184)-GM-CSF(9-127)( To abbreviate IG1), IL-6(24-184)-GM-CSF(9-127)( To abbreviate IG2).The novel gene coding for the six GM-CSF/IL-6 fusion protein was constructed by strategy of step by step cloning in pBV220 expression vector.