Current thoughts on feline immunodeficiency virus infection.

The feline immunodeficiency virus (FIV) is a novel feline retrovirus of the lentivirus subfamily that is known to induce immunodeficiency disorders in experimentally and naturally infected cats. Recent studies have characterized the stages of infection and specific immune deficits associated with FIV infection. Host cell populations harboring the virus have been better elucidated. Molecular cloning and nucleotide sequence analysis of the genomes of several isolates of FIV indicate sequence variation in the env gene of FIV, as has been found with other lentiviruses. Sequence of the genome has allowed the development of molecular reagents, including FIV DNA probes, polymerase chain reaction primers, and recombinant viral proteins, which have been and will be useful for FIV diagnostics and for pathogenesis studies. Investigations characterizing FIV as an animal model for human AIDS has yielded significant information concerning FIV infection in naturally infected cats and also may yield FIV vaccines and antiviral therapeutics useful for the pet cat population.