Construction of human surfactant protein B promoter luciferase reporter gene vectors and detection of their activities

Objective To construct human surfactant protein B (SP-B) gene promoter luciferase reporter plasmids and detect their transcriptional activities in H441 cells.Methods (1)The fragment of SP-B promoter (-218/+ 435 bp) was acquired from human genome DNA by polymerase chain reaction (PCR) amplification and then was inserted into pGM-T vector by the T4 DNA ligase.The vector was transfected into TOP10 E.coli.The positive clone was identified by DNA sequencing.The identified target SP-B promoter sequence was cloned into pGL3-basic vector to construct the recombinant vector pGL3-basic-SP-B-promoter and was identified by enzyme digestion and sequencing; (2)The pGL3-basic-SP-B-promoter vector was converted into pGL4.17-SP-B-promoter vector through enzyme digestion.The identified recombinant vectors and control plasmid pRL-TK were transfected into H441 cells by lipofectamine 2000,and luciferase assays was performed using the dual-luciferase reporter assay system.Results The sequences of SP-B promoter in the recombinant luciferase reporter plasmids were consistent with the one published on Genebank.The firefly/renilla luciferase activity ratio of pGL3-basic/pGL4.17-SP-B-promoter vector (2.8 ± 1.1,66.5±3.8) was significantly higher than pGL3-Basic,pGL4.17 control vector (0.2 ±0.1,4.3 ±0.4) with statistical significance (t =4.182,27.419,P =0.000),respectively.The SP-B promoter activity of pGL4.17-SP-B-promoter vector was significantly higher than pGL3-basic-SP-B-promoter vector (t =27.712,P =0.000).Conclusions The pGL3-basic/pGL4.17-SP-B-promoter vectors are successfully constructed with SP-B promoter activity in H441 cells and pGL4.17-SP-B-promoter vector is the better choice for further study with higher luciferase activity. Key words: Pulmonary surfactants/genetics;  Promoter regions (Genetics) ;  Luciferases/genetics; Recombination, genetic;  Transcription, genetic;  Plasmids/genetics