Vectors murine leukemia viruses

Miller, A. and Chen, F. (1996) Retrovirus packaging cells based on lOAl murine leukemia virus for production of vectors that use multiple receptors for cell entry. J VlrollO, 5564-5571. 

The most common retroviral vector is based on the amphotropic Moloney murine leukemia virus (MLV) (31). This system is particularly suitable for efficient in vitro cell transduction the amphotropic MLV has a broad cell tropism, it can be produced at relatively high titers (106—107 iu/mL), and allows for long-term transgene expression because of the viral integration in the host chromosomal DNA. 

There are severable methodologies for expressing siRNAs. One method for stable and controlled expression of siRNAs from the context of the cell is via the use of len-tiviral vectors. Lentiviruses, unlike retroviruses such as Moloney murine leukemia virus (MoMLV), tend to preferentially integrate downstream of active promoters within the active transcriptional unit, potentially limiting their overall oncogenicity... 

Maloney murine leukemia virus (MMLV) a vector commonly used in gene therapy (14.2) malon)l-CoAa three-carbon intermediate important in the biosynthesis of fatty acids (21.6) matrix (mitochondrial) the part of a mitochondrion enclosed within the inner mitochondrial membrane (1.6, 19.2)... 

Retroviral vector Derived from murine leukemia virus (MLV) Yes... 

The retroviral vectors in clinical use have mainly been derived from murine leukemia virus (MLV) [14]. MLV causes leukemia in mice and replication-competent retrovirus (RCR) in a contaminated vector preparation was shown to cause leukemia in severely immunosuppressed monkeys. RCR absence therefore has to be verified before human use of retroviraUy modified cells MLV vector use in vivo has been very rare. The genome of the retroviral vectors consists of two copies of single-stranded RNA, which contains one or more coding regions flanked by the viral control elements, the so-called long terminal repeat (LTR)... 

Barsov EV, Hughes SH (1996) Gene transfer into mammalian cells by a Rous sarcoma virus-based retroviral vector with the host range of the amphotropic murine leukemia virus. J Virol 70 3922-3929. 

Figure 2 Maps of murine leukemia virus (MLV)-derived retroviral and human lentiviral (HIV-derived) vectors, (a) Provimses of wild-type MLV and HIV. Note the more complex genome of HIV, which contains a number of accessory genes not present in MLV including vif, vpr, vpu, nef, rev, and tat. (b) MLV- and HIV-based derived vectors. Vectors are produced by providing the envelope and viral genes deleted from the vector in trans with stably transfected producer cell lines or by transient transfection. Abbreviations LTR, long terminal repeat viral packaging signal pro, promoter Ga, gag RRE, rev response element.

Johnson LG, Mewshaw JP, Ni H, Friedman T, Boucher RC, Olsen JC. Effect of host modification and age on airway epithelial gene transfer mediated by a murine leukemia virus-derived vector. J Virol 1998 72 8861-8872. 

---