Studies on the Expression of Recombinant Human MCAF/GM-CSF Fusion Protein and Its Biological Activities

With PCR technology and methods of DNA recombination in vitro, the fusion protein of GM-CSF with MCAF, the facto that has a directing effect on cells to a target, was generated by the construction of recombinant plasmids pMG 01, pMG 02 and pMG 03 with different nucleotide composition between its SD sequence and the initiation codon ATG under the control of lambdaP(R) P(L) promoter of vector pBV 220. Although no stable secondary structure exist in the translation initiation regions of all the recombinant plasmid constructed, the expression levels of the products with DH5 alpha (pMG 02) and DH5alpha (pMG 03) are much higher than that with DH5alpha (pMG01) which hardly expressed the product. The assay of Western blot indicated that the expressed product reacted with MCAF and GM-CSF antibodies, respectively. The assay of biological activities showed that the expressed product had apparent monocyte chemoattractant activity and supported the growth of the human GM-CSF-dependent cell line TF1, suggesting that the biological functions of MCAF and GM-CSF are compatible