The roles of vif and ORF-A genes and AP-1 binding site in in vivo replication of feline immunodeficiency virus.

To examine the in vivo roles of auxiliary genes and regulatory elements of feline immunodeficiency virus (FIV), the provirus load in various tissues of cats infected with each of the mutant viruses (delta vif, delta ORF-A and delta AP-1) was studied. Although all mutant viruses could infect various tissues, provirus loads in various tissues especially those in cats infected with delta vif virus were lower than those with the wild-type virus. Our results indicate the significance of vif and ORF-A genes and AP-1 binding site of FIV for efficient viral replication and full pathogenicity in cats.