Abstract: Novel HIV-2 proviruses, molecular clones, nucleic acids, polypeptides, viruses and viral components are described. The use of these compositions as components of diagnostic assays, as immunological reagents, as vaccines, as components of packaging cells, cell transduction vectors, and as gene therapy vectors is also described.

Abstract: Molecular clones of the feline immunodeficiency virus isolate PPR (FIV.sub.PPR) were obtained from a genomic library prepared from infected feline peripheral blood lymphocytes (PBLs). FIV.sub.PPR infected and replicated efficiently in feline PBLs but not Crandall feline kidney (CRFK) or G355-5 cells. In contrast, a clone designated 34TF10 of the prototypical FIV Petaluma isolate (FIV.sub.Pet) replicated inefficiently on feline PBLs while readily infecting and replicating in CRFK and G355-5 cells. The 34TF10 and PPR clones have an overall nucleic acid sequence identity of 91% while the env genes display only 85% conservation at the amino acid level. The long terminal repeats (LTRs) were 7% divergent between the two clones, with a lack of conservation in putative NF-.kappa.B, LBP-1, and CCAAT enhancer promoter sites. Full-length proviral clones will provide important biochemic, immunologic, and diagnostic reagents.