Establishment of a Pigtailed Macaque Model to Test the Effects of Chemoradiation and Ccr5 Gene Therapy on the Shiv Latent Viral Reservoir

Publication Type:

Journal Article

Source:

Journal of medical primatology, Volume 42, Number 5, p.267-267 (2013)

ISBN:

0047-2565

Keywords:

2013, Clinical Research Division, December 2013, Vaccine and Infectious Disease Division, Veterinary Sciences, Zoology

Abstract:

To date, HIV+ patients receiving hematopoietic cell therapy (HCT) have exhibited the most promise for control of viral replication in the absence of antiretroviral therapy. We are developing an NHP model of latent HIV infection in pigtailed macaques (M. nemestrina). Using this model, we will test the effects of chemoradiotherapy and CCR5 gene therapy on reducing the latent viral reservoir. In collaboration with Sangamo Biosciences, we are using targeted zinc finger nucleases (ZFNs) to disrupt the genetic locus of the CCR5 coreceptor in CD34+ hematopoietic stem cells. Concurrently, we are developing a model of HIV infection in M. nemestrina using SHIV1157ipd3N4, a highly CCR5-tropic clade C env-SHIV. Our goals are to characterize the latent viral reservoir in infected macaques on antiretroviral therapy (Tenofovir/Emtricitabine/Raltegravir) and assess the effect of HCT with CCR5-deleted stem cells with and without chemoradiation. Using SHIV-C, we have observed peak viremia of 107 viral copies/mL plasma, and acute depletion of CD4+ cells in the gut mucosa, but not in peripheral blood, consistent with past results. In ex vivo experiments, we have identified pseudotyped lentivirus and mRNA electroporation as effective methods for delivery of CCR5-specific ZFNs to M. nemestrina CD34+ cells. Further, we have demonstrated the efficacy of our macaque CCR5-specific ZFNs in maca- que cell lines, as well as primary CD34+ and CD4+ cells. In sum, our early data demonstrate that CCR5 disruption in M.Nemestrina hematopoietic cells is feasible, and that SHIV1157ipd3N4 infection of these animals results in depletion of CD4+ cells at anatomical reservoir sites. Currently, we are initiating TFV/FTC/ RAL therapy in our two pilot study animals, and will longitudinally measure drug pK/pD as a function of viral load in reservoir sites, including gut, bone marrow, and brain (CSF). Future experiments will characterize the latent reservoir in ART-suppressed M. nemestrina, and challenge CCR5-deficient animals with CCR5-tropic env-SHIVs.

Notes:

PT: J; NR: 0; TC: 0; J9: J MED PRIMATOL; PG: 1; GA: 217BR