Retroviral and Lentiviral Vectors for the Induction of Immunological Tolerance

Figure 3

Engineering of the lentivector gene transfer system. The HIV-1 genome organisation is shown on the top, from 5′ to 3′, long-terminal repeats (LTR), packaging signal (PS), GAG-PRO-POL-In genes, envelope gene (ENV), and the accessory genes Vif, Vpr, Rev, Tat, Nef, and the Rev-response element (RRE). This genome is separated into three different plasmid constructs. The transfer vector (vector), that contains at least, the LTR, PS, and the internal promoter controlling the transcription of the gene of interest. The packaging plasmid, which leads to the expression of the GAG-POL-PRO-IN, rev, and tat genes under the control of the cytomegalovirus (CMV) promoter. Lastly, the envelope plasmid, which expresses the required envelope glycoprotein which will confer the tropism to the vector particle. Cotransfection of these three plasmids will lead to the production of lentivirus-like particles with the capacity of transducing target cells independently of their cell cycle.