Lentivirus Vector Based on Simian Immunodeficiency Virus: Development and Use

Vector systems based on human immunodeficiency viruses (HIVs) (1 ) allow an efficient and stable gene transfer into nondividing cells (2 ,3 ). Because of the pathogenicity of the parental virus, the use of lentiviral vectors based on feline immunodeficiency virus (4 ,5 ), equine infectious anemia virus (6 ), or simian immunodeficiency virus (SIV) (7 ,8 ) has also been explored. SIV is closely related to HIV, and some strains of SIV can induce an AIDS-like disease in nonhuman primates. This animal model has been extensively used to study the pathogenesis of immunodeficiency virus infections and should also be valuable for a preclinical safety assessment of SIV-based vectors. Although SIV can replicate in human CD4+ cells, the course of laboratory-acquired infections suggests greatly reduced virulence in comparison with HIV (9 ).