CROI 2015 Program and Abstracts

Abstract Listing

Poster Abstracts

Results: In testicular tissues, we found that MRP2 and OATP2B1 were highly expressed at the mRNA level, BCRP showed moderate expression, while expression of P-gp, MRP1, OATP1A2, OATP1B1, OAT1, OCT1, CNT1, ENT2, CYP2D6 and CYP3A4 were low. However, we were able to detect robust protein expression for all transporters and metabolic enzymes analysed with the exception of OATP1A2 and OCT1. Overall, gene and protein expression did not differ significantly between the uninfected and ART-treated HIV-1-infected men. Our fluorescence microscopy results also indicate that transporters and metabolic enzymes are not limited to BTB localization but can be found throughout the testicular tissue. Conclusions: It has been well documented that drug transporters and metabolic enzymes are capable of interacting with many commonly used ARVs, and could significantly affect drug disposition into tissues, especially at key blood-tissue barriers such as the blood-brain barrier. Our data are the first to demonstrate protein expression and localization of key drug transporters and metabolic enzymes in the testes of ART-treated HIV-1 infected men. Their presence suggests the testes are a complex pharmacological compartment Elias P. Rosen 1 ; Corbin G.Thompson 2 ; MarkT. Bokhart 1 ; Craig Sykes 2 ;Yuri Fedoriw 2 ; Paul Luciw 3 ; David C. Muddiman 1 ; Angela D.M. Kashuba 2 1 North Carolina State University, Raleigh, NC, US; 2 University of North Carolina, Chapel Hill, NC, US; 3 University of California Davis, Davis, CA, US Background: Methods to accurately evaluate ARV biodistribution within tissues are needed to design effective HIV therapy and eradication strategies. Here, we characterize the spatial distribution of efavirenz (EFV) within suspected reservoir tissues of a primate model using a novel approach to mass spectrometry imaging (MSI). Methods: Reservoir tissues (GALT, lymph nodes, brain, testes) were removed at necropsy from an uninfected rhesus macaque dosed orally to steady-state with EFV. 10 μ m cryosections of snap frozen tissue were discretized into 10 -4 mm 3 voxels, resolving 100 μ m features, and analyzed using an infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) source coupled to a Thermo Q-Exactive mass spectrometer. Response was calibrated by EFV standards on blank tissue, with a limit of detection of 180 attomole/voxel (57 fg/mm 3 tissue). The results were visualized using custom analysis software. Serial sections of tissue were utilized to validate MSI results by LC-MS, and stained to correlate observed EFV response with tissue morphology (H&E) and immunohistochemistry (CD3 staining). Results: The presence of EFV was confirmed in all reservoir tissues by MSI, with varying total EFV penetration observed between tissue types. Mapping of EFV response indicated heterogeneous drug exposure. EFV concentration was substantially increased within the mucosa and lamina propria of the colorectal epithelium, specifically corresponding to high density of CD3+ T cells. No such mucosal enhancement was observed in the ileum. Lymph nodes showed focally increased signal in association with some, but not all, primary follicles. Within the brain, grey matter had enhanced EFV exposure relative to white matter. EFV concentration was lowest (167 pg/g tissue) in the basal ganglia, increasing to approximately two-fold in most other tissues (cerebrum, lymph nodes, spleen, testes, and most GALT), and highest in rectal tissue (3.6 fold). that could limit the penetration of several ARVs in this tissue. ( Supported by CIHR and OGS) 535 Imaging the Spatial Distribution of Efavirenz in Intact HIV Tissue Reservoirs

Poster Abstracts

Conclusions: This study is the first to map the biodistribution of an ARV in viral reservoir tissues. Differences in mucosal enhancement in the gut suggest potential differences in biologic transporter activity. Heterogeneous lymph node distribution may indicate insufficient exposure at important sites of viral replication. By differentiating and quantifying drug exposure between cell types within tissue, IR-MALDESI MSI offers a new capability to evaluate drug efficacy and will help inform the selection of optimal interventions to target active viral reservoirs.

WEDNESDAY, FEBRUARY 25, 2015 Session P-I1 Poster Session

Poster Hall

2:30 pm– 4:00 pm Drug Development 536 Inhibition of HIV-1 Replication by a Novel Acylguanidine-Based Molecule Philip Mwimanzi 1 ; IanTietjen 2 ; Aniqa Shahid 1 ; Scott C. Miller 2 ; David Fedida 2 ; Zabrina L. Brumme 1 ; Mark Brockman 1 1 Simon Fraser University, Burnaby, Canada; 2 University of British Columbia, Vancouver, Canada

Background: Despite major successes in antiretroviral therapies against HIV-1, discovery of new drugs is necessary to enhance treatment options and counter resistance. BIT225 is an acylguanidine based compound that is reported to inhibit HIV-1 replication in myeloid cells by blocking the viroporin function of Vpu. Here, we test the anti-HIV-1 activity of a novel acylguanidine compound SM111. Methods: We used a GFP-reporter T cell assay to test the ability of SM111 to inhibit replication of WT NL4.3, NL4.3 Δ Vpu (lacking vpu ), and recombinant NL4.3 strains encoding major resistance mutations in pol for inhibitors of Reverse Transcriptase (RTI), Protease (PI) and Integrase (INI). Viral spread was monitored by flow cytometry over a 7-day period.

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CROI 2015