Recombinant Feline Immunodeficiency Virus Vectors: Preparation and Use

Traditional onco-retroviral vector packaging systems, typified by those based on Moloney murine leukemia virus (MMLV), have many appealing features for gene transfer. MMLV vectors stably integrate their genome into their target cells, can package and carry up to 6.5 kb of foreign insert, can be produced free of helper virus, and, because of their low immunogenicity, can be administered in vivo multiple times to the same organism. The major disadvantage of these vectors; however, is their inability to transduce nondividing cells (1 ).