Generation of a dual RT Env SHIV that is infectious in rhesus macaques
Article first published online: 2 JUL 2010
Published 2010. This article is a US Government work and is in the public domain in the USA
Journal of Medical Primatology
Volume 39, Issue 4, pages 213–223, August 2010
How to Cite
Smith, J. M., Dauner, A., Li, B., Srinivasan, P., Mitchell, J., Hendry, M., Ellenberger, D., Butera, S. and Otten, R. A. (2010), Generation of a dual RT Env SHIV that is infectious in rhesus macaques. Journal of Medical Primatology, 39: 213–223. doi: 10.1111/j.1600-0684.2010.00434.x
- Issue published online: 2 JUL 2010
- Article first published online: 2 JUL 2010
- Accepted May 19, 2010.
- HIV interventions recombinant HIV;
- mucosal transmission
Background The best current animal model for HIV infection and evaluation of antiviral compounds is the Simian–human immunodeficiency virus (SHIV)/macaque system. There are multiple recombinant SHIVs available, but these viruses have limitations in evaluating combination drug strategies for prevention. Drug combinations that target reverse transcriptase (RT, either nRTI or nnRTI) and envelope (entry or fusion inhibitors) have to be tested separately, which does not permit the assessment of additive, synergistic, or antagonistic effects of ARV combinations. We describe construction of a dual SHIV containing both HIV RT and a CCR5-specific HIV envelope gene in a simian immunodeficiency virus backbone.
Methods The RT Env SHIV molecular clone was constructed using RT SHIV and SHIV162p3 sequences as templates to generate RT Env SHIV. RT Env SHIV was expanded in vitro in CD8-depleted macaque peripheral blood mononuclear cells (PBMC). Recombinant virus was used to infect a rhesus macaque (4.3 × 104 tissue culture infectious dose [TCID50], intravenously [IV]). A second passage in a macaque by IV transfer of 10 ml of blood obtained from the first infection was also done. The in vivo adapted virus stock from these macaques was used to produce high titer stocks in vitro and used to rectally infect an additional macaque.
Results Peak viral load reached 6 × 105 vRNA copies/ml in plasma in both IV-exposed macaques and remained detectable in the one animal for 16 weeks after infection. A viral stock (1.68 × 104 TCID50) derived from the second macaque passage has been produced in CD8-depleted rhesus PBMC and was successfully used to demonstrate mucosal transmission. The resulting RT Env SHIV retained the sensitivity to HIV RT and entry inhibitors of its parental viruses.
Conclusions The objective of this study was to develop and characterize a SHIV recombinant virus for evaluating the efficacy of ART and microbicide products that target both HIV RT and/or Env-mediated entry. RT Env SHIV can productively infect macaques by both the IV and mucosal route, making it a valuable tool for transmission studies.