FIV Vectors

Lentiviral vectors combine two useful vector properties: permanent integration and transduction of nondividing cells. Replication-defective lentiviral vectors were originally derived entirely from the human lentivirus human immunodeficiency virus type 1 (HIV-1) (1 ,2 ). Application of pseudotyping with broadly tropic, physically stable envelope glycoproteins (3 ) permitted efficient transduction of nonlymphocytes by HIV-1 vectors in vitro and in vivo (4 ,5 ). The first nonprimate lentivirus-based vector was derived from feline immunodeficiency virus (FIV) (6 ). Subsequently, substantial improvements have been made in the design and capabilities of FIV vectors, and recently identified FIV elements (central polypurine tract, central termination sequence, and packaging signal) have been incorporated (7 ,8 ). This chapter will briefly present an overview of FIV vectors, describe recent improvements, and then explain practical methods for production and use.