Expression Of Human Growth Hormone Gene And Effect On Immune Function In Mouse

Objective The study is to explore the expression of human growth hormone (hGH) gene in mouse and the effects of over-expression GH on the concentration of IL-2,IFN-γ and TNF-α in serum. Methods First, recombinant eukaryotic expression plasmid pcDNA3-hGH was constructed by molecular cloning technology and was identified by restriction enzyme analysis and sequencing. Second, after the recombinant plasmid pcDNA3-hGH was transfected into COS-1 cells by lipofection, the COS-1 cells were stained by immunohistochemistry and the concentrations of hGH in supernatants were measured by ELISA. The activity of hGH in supernatant was detected by Jurkat cell proliferation assay. Third, The pcDNA3-hGH plasmids were injected into mouse skeletal muscle. After 5d,15d,25d,40d and 60d of injection, the serum were separated, and then GH, IL-2,IFN-γand TNF-αwere assayed by ELISA. Meanwhile, immunohistochemical staining of skeletal muscles tissue was performed to identify the expression of hGH. Results Frist, restriction enzyme analysis of recombinant plasmid pcDNA3-hGH was correct and the sequence data of hGH was identical to that of document. Second,the COS-1 cells secrecting hGH could be seen and hGH added up to 440ng/ml in supernatant. Then, supernatant was added to the Jurkat cells and the proliferation of Jurkat cells could be promoted. Third, the expressions of hGH could been observed in injection and the concentrations of hGH in serum were obviously higher than those of controls. However, the concentrations of IL-2,IFN-γ and TNF-α in serum were not different from those of the controls. Conclusion The study indicated that the longer-time GH gene expression were obtained in muscle by direct injecting plasmid. On the other hand, the high concentration GH in circulation could not significantly affect the secretion of several important cytokine. This could provide some theoretical bases for the widely clinical application of recombinant human GH(rhGH) and new method for gene therapy of growth hormone deficiency(GHD).