Lentiviral

To circumvent this problem, vectors that are based on lentiviruses have been developed. In contrast to prototypic retroviruses, lentiviruses do not require cell division for integration. Gene-therapy vectors have been developed from a broad spectrum of lentiviruses including human immunodeficiency vims (HIV), simian and feline immunodeficiency vims as well as visna/maedi vims. The most widely used lentiviral vector system is based on HIV-1. These vectors can efficiently transduce a broad spectrum of dividing and nondividing cells including neurons, hepatocytes, muscle cells, and hematopoietic stem cells [1,2]. 

To address biosafety concerns, self-inactivating lentiviral vectors and stable packaging cell lines have been developed. 

Finally, lentiviral vectors have been shown to transduce human embryonic stem cells. Therefore, this type of gene-therapy vector might also be used in stem cell-based therapies. 

Levine BL, Humeau LM, Boyer J et al (2006) Gene transfer in humans using a conditionally replicating lentiviral vector. Proc Natl Acad Sci USA 103(46) 17372-17377... 

Li MJ, Kim J, Li S, Zaia J, Yee JK, Anderson J, Akkina R, Rossi JJ (2005b) Long-term inhibition of HlV-1 infection in primary hematopoietic cells by lentiviral vector delivery of a triple combination of anti-HIV shRNA, anti-CCR5 ribozyme, and a nucleolar-localizing TAR decoy. Mol Ther 12 900-909... 

Qin XF, An DS, Chen ISY, Baltimore D (2003) Inhibiting HlV-1 infection in human T cells by lentiviral-mediated delivery of small interfering RNA against CCR5, Proc Natl Acad Sci USA 100 183-188... 

For intracellular immunization strategies of hepatitis B and C, lentiviral vectors have been tested (Matskevich et al. 2003 Parouchev et al. 2006). However, as the turnover of hepatocytes is thought to be much slower than that of HPC or T cells, nonintegrating vectors that carry a reduced risk of insertional mutagenesis are favored (Nowak et al. 1996). 

Mautino MR, Morgan RA (2000) Potent inhibition of human immunodeficiency virus type 1 reph-cation by conditionally replicating human immunodeficiency virus-based lentiviral vectors expressing envelope antisense mRNA, Hum Gene Ther 11 2025-2037... 

Nash KL, Alexander GJ, Lever AM (2005) Inhibition of hepatitis B virus by lentiviral vector delivered antisense RNA and hammerhead libozymes. J Viral Hepat 12 346-356... 

Vassalli G, Simeoni E, Li JP, Fleury S. Lentiviral gene transfer of the chemokine antagonist RANTES 9-68 prolongs heart graft survival. Transplantation 2006 81 240-246. 

Unutmaz D, Xiang W, Sunshine Ml, Campbell J, Butcher E, Littman DR. The primate lentiviral receptor Bonzo/STRL33 is coordinate regulated with CCR5 and its expression pattern is conserved between human and mouse. J Immunol... 

Studies in knockout mice indicate that the p2 nAChRs are necessary for nicotine self-administration, DA-dependent locomotor activation, and nicotine-associated enhancement of NAc DA release.40-51 53 Combined with studies showing that antagonism of the high-affinity nAChRs block self-administration,44-54 it would appear that p2 nAChRs are particularly critical for nicotine reinforcement. Unlike wild-type mice that self-administer both cocaine and nicotine, p2 nAChR-null mutant mice learn to self-administer cocaine normally, but stop bar pressing as though receiving saline when cocaine is switched to nicotine.40 Self-administration of VTA nicotine and associated DA release is rescued, however, in p2 nAChR knockout mice with lentiviral-mediated expression of P2 subunit DNA in the VTA.55 Whereas several configurations of the p2 nAChRs exist at the... 

Fridell, R. a., et al.. Identification of a novel human zinc finger protein that specifically interacts with the activation domain of lentiviral Tat proteins. Virology, 1995, 209(2), 347-57. 

Although this study provided insight into the clonal composition of human HSC hierarchy, it was unknown if the ex vivo manipulations required for retroviral marking had quantitative or qualitative effects on SRC fates. The developments in lentivector transduction protocols enabled efficient transduction of SRC in the absence of cytokine and serum stimulation . Using minimal ex vivo manipulation to mark hematopoietic cells with lentiviral integration, the fates of SRC were evaluated . As reported previously using retroviral-marking, lentivector transduced short-term SRC contributed rapidly... 

Guenechea G, Gan Of, Inamitsu T, et al. Transduction of human CD34+ GD38 bone marrow and cord blood derived SCID-repopulating cells with third-generation lentiviral vectors. Mol Ther. 2000 1 566 573. 

Any alternative vector that allows a tetracycline-regulated expression of your shRNA can be used. Remember to consider the DNA delivery method (plasmid transfection or lentiviral transduction) to select the right vector. In the case of lentiviral infection, pLenti4/TO/V5-DEST (Invitrogen) could be another option. 

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