hG-CSF cDNA Cloning and the Construction and Applicaltion in Gene Therapy of Its Retroviral Vector / 中国肿瘤生物治疗杂志

ABSTRACT

The hG -CSF cDNA was cloned by RT-PCR and confirmed by sequencing, which contains the full length of hG-CSF encoding region and parts of 5 '、3' non - coding region. Then the hG - CSF retroviral vector pLGSN was constructed by orientationally inserting the hG-CSF cDNA into the EcoRI/XhoI cloning sites of pLXSN vector. Packaged with CRE and CRIP packaging cell lines which are considered to be unlikely to produce helper viruses, the final pLGSN retrovirion titer reached 1. 1 ?106 CFU/ml. During constitutive passaging, the CRIP - LGSN cell clone produced relatively stable tilers of pLGSN retrovirion, ranging from 6. 8?105CFU/ml to 1. 1?106CFU/ml. By infecting the murine fibroblast cell line NIH3T3 with pLGSN retrovirion, a cell clone designated as NIH3T3 -G -CSF was obstained, secreting 168U/ml G-CSF . The integration and expression of hG-CSF gene in this cell clone were confirmed by Southern and Northern blotting analyses. Western blotting has also detected specifically the hG-CSF protein in the condensed supernalants from NIH3T3-G-CSF cells . After packaging the hG-CSF-secreting fibroblasts with collagen and implanting them into synergenic mice peritoneally , we detected a certain levels of G-CSF in the sera of mice, which suggested the implanted NIH3T3-G-CSF fibroblast cells could constitutively express and release hG-CSF in vivo. Our data showed the constructed hG-CSF retroviral vector could be used to further investigate the fibroblasl-mediated hG-CSF gene therapy .