HIV-2 Vectors

Lentivirus vectors are expected to become excellent tools for gene transfer in gene therapy and functional genomics and for engineering transgenic animals. When fully developed, their use will cover a whole gamut of endeavors, from discovery to therapeutics. Because they integrate into the host cell genome and become a permanent member of the genetic makeup of the recipient cell, retroviruses are well suited for stable expression of the transgenes. This property is shared by all retroviruses, including lentiviruses (1 ). Apart from the poor suitability of the conventional retroviral vectors for human gene therapy, what brought the prospects of lentiviral vectors to the forefront was their ability to cause gene transfer into nondividing, quiescent cells as well as dividing cells (2 ). This attribute will become increasingly important as more knowledge is gained about the biology of stem cells and a more optimized technology is developed for transplantation of genetically modified cells.