Abstract: With the help of X-ray structural analyses of drug-resistant HIV proteases and molecular modeling, a new type of inhibitor with a small P3 residue has been developed. These inhibitors are effective against HIV and its drug-resistant mutants, as well as FIV. Modification of existing HIV protease inhibitors effective against the wild type and drug-resistant mutants and further supports that FIV protease is a useful model for drug-resistant HIV proteases, which often are developed through reduction in size of the binging region for the P3 group or the combined P3 and P1 groups.

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.

Abstract: The present invention relates to a leukemia-associated virus immunogens, vaccines, antibody combining sites and assays. The immunogens are relatively short polypeptides with peptide sequences corresponding to the antigenic determinant domains of a leukemia-associated virus envelope protein. The immunogens when introduced into a host stimulate the production of antibodies which immunoreact with the polypeptides and the leukemia-associated virus.

Abstract: The present invention relates to a leukemia-associated virus immunogens, vaccines, and assays. The immunogens are relatively short polypeptides with peptide sequences corresponding to the antigenic determinant domains of a leukemia-associated virus envelope protein. The immunogens when introduced into a host stimulate the production of antibodies which immunoreact with the polypeptides and the leukemia-associated virus.The immunogens may be used together with other components such as adjuvants to form immunizing compositions such as vaccines. The antibodies may be used together with other components in an assay system to detect the presence of a leukemia-associated virus antigen in a body fluid sample. The antibodies can also be used in the treatment of leukemia-associated virus infections.