title: [Expression of human IL-12 in mammalian cell and study on its biological activities].
abstract: OBJECTIVE
  To obtain recombinant human interleukin 12 by genetic engineering, and to explore possibility of its clinical application in treatment of tumor and chronic hepatitis.
  
  
  METHODS
  Bicistronic expression vector P35-IRES-P40 was constructed for the simultaneous translation of IL-12 p35 and p40 cDNA subunit through internal ribosomal entry sites (IRES). pCI-dhfr-P35-IRES-P40 vector was constructed for expression in CHO-DHFR- cells. Positively cloned cells were screened by means of ELISA. Pools of clones with increased expression of IL-12 could be generated by selection in methotrexate. To determine the biological activities of rhIL-12, PHA-activated lymphoblasts proliferation assay and IFN-gamma induction assay were used in this study.
  
  
  RESULTS
  Genetically engineered cells expressing hIl-12 were obtained and all the cell lines showed the stabile expression of rhIL-12 in high efficiency and good growth properties.
  
  
  CONCLUSIONS
  rhIL-12 have good biological activities, it can stimulate activation and proliferation of T cells and induce production of IFN-gamma.
authors.affiliation: Institute of Viral Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Hong-Yuan
authors.initials: HY
authors.lastname: Jiao
authors.forename: Mei-Yun
authors.initials: MY
authors.lastname: Zhan
authors.forename: Min-Zhuo
authors.initials: MZ
authors.lastname: Guo
authors.forename: Yao
authors.initials: Y
authors.lastname: Yi
authors.forename: Yu
authors.initials: Y
authors.lastname: Cong
authors.forename: Rui-Guang
authors.initials: RG
authors.lastname: Tian
authors.forename: Wen-Ying
authors.initials: WY
authors.lastname: Zhang
authors.forename: Sheng-Li
authors.initials: SL
authors.lastname: Bi
mesh_terms: D000818:Animals; D015153:Blotting, Western; D016466:CHO Cells; D049109:Cell Proliferation / Q000187:drug effects; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D018664:Interleukin-12 / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000378:metabolism / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects; D014162:Transfection
chemical_list: D011994:Recombinant Proteins; D018664:Interleukin-12