title: High natural permissivity of primary rabbit cells for HIV-1, with a virion infectivity defect in macrophages as the final replication barrier.
abstract: An immunocompetent, permissive, small-animal model would be valuable for the study of human immunodeficiency virus type 1 (HIV-1) pathogenesis and for the testing of drug and vaccine candidates. However, the development of such a model has been hampered by the inability of primary rodent cells to efficiently support several steps of the HIV-1 replication cycle. Although transgenesis of the HIV receptor complex and human cyclin T1 have been beneficial, additional late-phase blocks prevent robust replication of HIV-1 in rodents and limit the range of in vivo applications. In this study, we explored the HIV-1 susceptibility of rabbit primary T cells and macrophages. Envelope-specific and coreceptor-dependent entry of HIV-1 was achieved by expressing human CD4 and CCR5. A block of HIV-1 DNA synthesis, likely mediated by TRIM5, was overcome by limited changes to the HIV-1 gag gene. Unlike with mice and rats, primary cells from rabbits supported the functions of the regulatory viral proteins Tat and Rev, Gag processing, and the release of HIV-1 particles at levels comparable to those in human cells. While HIV-1 produced by rabbit T cells was highly infectious, a macrophage-specific infectivity defect became manifest by a complex pattern of mutations in the viral genome, only part of which were deamination dependent. These results demonstrate a considerable natural HIV-1 permissivity of the rabbit species and suggest that receptor complex transgenesis combined with modifications in gag and possibly vif of HIV-1 to evade species-specific restriction factors might render lagomorphs fully permissive to infection by this pathogenic human lentivirus.
authors.affiliation: Department of Infectious Diseases, Virology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Hanna-Mari
authors.initials: HM
authors.lastname: Tervo
authors.forename: Oliver T
authors.initials: OT
authors.lastname: Keppler
mesh_terms: D000818:Animals; D004252:DNA Mutational Analysis; D018076:DNA, Complementary / Q000235:genetics; D004195:Disease Models, Animal; D015658:HIV Infections / Q000635:transmission*; D016325:HIV Long Terminal Repeat / Q000235:genetics; D015497:HIV-1 / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D008264:Macrophages / Q000821:virology*; D051379:Mice; D041681:NIH 3T3 Cells; D011817:Rabbits; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000821:virology*; D053586:Virus Internalization; D014779:Virus Replication / Q000502:physiology*
chemical_list: D018076:DNA, Complementary