Objective:hIL 2/mGM CSF fusion gene was constructed and expressed in E.coli.recombinant hIL 2/mGM CSF fusion protein had both biological activity of hIL 2 and mGM CSF.Methods:The hIL 2 and mGM CSF genes were amplified by PCR (splicing by overlap extension,SOE) and ligated with two prolines linkers.Then the fusion gene was cloned into vector pLY4 and PBV220.The recombinant plasmid were transfected into E.coli and expressed.Results:The sequence of hIL 2/mGM CSF fusion gene was correct the hIL 2/mGM CSF fusion protein was highly expressed in E.coli and that comprises 20% of total bacterial protein.The results of biological activity assay showed that the expressed product possessed both of the activities of hIL 2(4.5?10 5 U/mg) and mGM CSF(3.85?10 6 U/mg).Conclusion:Have successful constructed the recombinant hIL 2/mGM CSF fusion protein which possessed bioactivities similar to that of the natural hIL 2 and mGM CSF.

Objective: To prepare and identify recombinant human IL 2/GM CSF(rhIL 2/GM CSF) fusion protein antibodies and to study its specificity and its effect on fusion protein biological activity. Methods: rhIL 2 /GM CSF fusion protein was purified by DEAE Sepharose FF ion exchange chromatography. The purified protein was used to immunize rabbits for the preparation of antisera. The titer and specificity of the antisera were detected by ELISA and Dot ELISA and the biological activity by cell proliferation. Results: The antisera not only reacted with the rhIL 2/GM CSF, IL 2 and GM CSF, but also inhibited the biological activity of the rhIL 2/GM CSF, IL 2 and GM CSF. Conclusion: The obtained antisera can be used to study the structure and function of the rhIL 2/GM CSF.