Presenting Author:

Katarina Kotnik Halavaty, Ph.D.

Principal Investigator:

Thomas Hope, Ph.D.

Department:

Cell and Molecular Biology

Keywords:

SIV infection, female reproductive tract, Pigtail Macaque, TDF IVR, drug distribution

Location:

Third Floor, Feinberg Pavilion, Northwestern Memorial Hospital

B17 - Basic Science Women's Health Research

Drug distribution and infection sites in macaque female reproductive tract

Prevention of HIV transmission using a tenofovir disoproxil fumarate (TDF)-eluting intravaginal ring (IVR) requires the right drug at the right place at the right time. We demonstrate the ability to locate the initial site of infection, to identify additional sites of infection, and to measure the drug distribution within an IVR-protected macaque female reproductive tract (FRT). Six pigtail macaques were treated with TDF-IVRs for 28 days, and vaginally challenged with a high dose of a single round non-replicative SIV-based vector expressing Luciferase and mCherry reporter genes (JRFL pseudotyped LICh vector). The isolated FRT was treated with luciferin to detect Luciferase activity using In Vivo Imaging System (IVIS), allowing us to identify the initial site of the infection. The tissue was sectioned and imaged further under IVIS. Tissue samples were further sectioned and analyzed with fluorescent microscopy and nested PCR to determine additional sites of infection. Tissue samples were processed and TFV concentrations were quantified using LC-MS/MS, with 13C-labeled TFV as an internal standard. Infection events were detected in the ovaries in two animals using IVIS. Transduced cells were identified in ovaries of five out of six IVR treated animals. Nested PCR data demonstrated frequent viral infections in vagina and cervix of four out of six IVR treated animals. TFV levels were found to be variable throughout the FRT, with the highest concentrations found in the upper vagina/lower cervical area, near the site of the ring. The concentration of TFV in the FRT of the macaques was in the range of 70- 35,000 fmol/mg of tissue. In the uterus and ovaries, the TFV concentration is near the IC50 of TFV in PBMC’s. Utilizing reporter viruses allows us to perform complete pharmacokinetic and pharmacodynamic studies at both the anatomical and cellular levels. Our results demonstrate the gradient of tissue drug levels emanating from the site of the ring and both the initial and additional sites of viral infection. Future Directions: Two antiretroviral drug delivery systems, the TDF IVR and oral TDF will be analyzed in FRT of nonhuman primates. We will compare the two TDF delivery methods in terms of drug distribution patterns and viral protection within the FRT tissue. Significance: This important and novel piece of research helps us to understand the complex interplay between viral infection events and protective drug levels. This study will also provide researchers with the necessary framework to develop a variety of topical ARV systems, thereby empowering women to directly control the risk of HIV infection to themselves and their families.