载体介绍：

pLAPSN contains elements derived from Moloney murine leukemia virus (MoMuLV) and Moloney murine sarcoma virus (MoMuSV), and is a control vector for establishing a retroviral gene delivery and expression system (1–3). This vector was created by cloning the gene for human placenta alkaline phosphatase (AP) into the Xho I site in the multiple cloning site of the pLXSN Retroviral Vector (Cat. No. 631509). Upon transfection into a packaging cell line, pLAPSN can transiently express, or integrate and stably express, a transcript containing Ψ+ (the extended viral packaging signal) the human placenta alkaline phosphatase gene, and a selectable marker. The 5’ viral LTR in this vector contains promoter/enhancer sequences that control expression of the alkaline phosphatase gene. The SV40 early promoter (PSV40e) con­trols expression of the neomycin resistance gene (Neor), which allows antibiotic selection in eukaryotic cells. pLAPSN also includes the Col E1 origin of replication and E. coli Ampr gene for propagation and antibiotic selection in bacteria.

 

使用方法：

 

pLAPSN can be used in control experiments to establish retroviral gene transduction proce­dures. After being transfected into a packaging cell line ,RNA frm the vector is packaged into infectious, replication-incompetent retroviral particles. pLAPSN does not contain the structural genes (gag, pol, and env) necessary for particle formation and replication; however, these genes are stably integrated into PT67 (4–7). Subsequent introduction of pLAPSN, containing Ψ+ (psi), transcription and processing elements, and the alkaline phosphatase gene, produces high-titer, replication-incompetent infectious virus. That is, these retroviral particles can infect target cells and transmit the al­kaline phosphatase gene, but cannot replicate within these cells since the cells lack the viral structural genes. The separate introduction and integration of the structural genes into the packaging cell line minimizes the chances of producing replication-competent virus due to recombination events during cell proliferation. The expression of alkaline phosphatase can be confirmed using a standard assay.