CROI 2015 Program and Abstracts

Abstract Listing

Poster Abstracts

414 Impact of IFN α -2a on the Replication-Competent HIV-1 Reservoir in CD4+ T Cells Sara Morón-López 2 ; Maria Salgado 2 ; Dan Ouchi 2 ; Mari Carmen Puertas 2 ;Toni Jou 3 ; CristinaTural 3 ; Jordi Navarro 1 ; Mercedes Perez-Bernal 1 ; Manel Crespo 1 ; Javier Martínez-Picado 2 1 Hospital Universitari Vall d’Hebron, Barcelona, Spain; 2 AIDS Research Institute irsiCaixa, Barcelona, Spain; 3 Fundació Lluita contra la SIDA, Barcelona, Spain Background: Antiretroviral therapy (ART) suppresses HIV-1 progression, but does not eliminate residual viral production of the reservoirs that perpetuate the infection, and constitute the limiting factor for HIV-1 cure. Previous data suggest that IFN α controls HIV-1 replication in patients without ART and decreases proviral DNA in peripheral CD4+ T cells. However, we ignore whether IFN α affects the replication-competent HIV-1 reservoir in vivo . Methods: This open, prospective study included 21 HIV-1 infected ART-suppressed (HIV-RNA<25copies/ml) and HCV-coinfected patients (HCV-RNA>10,000IU/L). Ten patients (IFN group) were treated with pegilated IFN α -2a, pegIFN (180 μ g/sc/week), and RBV (800-1200mg/d); 11 subjects (control group) did not receive treatment. The replication-competent reservoir was determined by quantitative viral outgrowth assay, at days 0 and 28, and reported as infectious units per million of cells (IUPM). Proviral DNA and cell-associated HIV RNA were quantified by droplet digital PCR, ddPCR, between days 0 and 28 of the study. mRNA expression of APOBEC3G, TRIM5 α , TRIM22 and BST2 was measured by qPCR. All parameters were analyzed in peripheral CD4+ T cells. Results: Subjects’ characteristics are summarized in table 1. Although IUPM did not significantly change between d0 and d28 in any group, pegIFN/RBV administration caused a significant increase in IUPM data dispersion (Levene test, p=0.05), not observed in the control group. These data suggest that pegIFN/RBV perturbs the replication-competent reservoir in peripheral CD4+ T cells. Longitudinally, we did not observe significant differences in cell-associated HIV-1 DNA copies, neither at d9 nor d28. Median [IQR] cell-associated HIV RNA decreased significantly in the IFN group (d0: 0.92[0.26-3.29]; d28: 0.25[0.02-0.96]), whereas did not change in the control group (d0: 0.1287[0.07-1.45]; d28: 0.13[0.05-0.42]) (Wilcoxon signed rank test, p=0.0488 and p=0.1934, respectively), suggesting an inhibitory effect of IFN on HIV expression. APOBEC3G, TRIM5 α , TRIM22 and BST2 expression was significantly up-regulated at d9 and d28 in the IFN group, and remained stable in the control group.

Conclusions: PegIFN/RBV perturbs the replication-competent reservoir in peripheral CD4+ T cells and decreases cell-associated HIV-1 RNA, probably through the inhibition of HIV transcription by TRIM22. However, after 28 days of treatment no significant decrease was observed in replication-competent or in proviral DNA reservoir. 415 Immune ModulationWith Rapamycin as a Potential Strategy for HIV-1 Eradication Alyssa R. Martin ; Robert F. Siliciano Johns Hopkins University School of Medicine, Baltimore, MD, US Background: Despite effective combination antiretroviral therapy (cART), HIV-1 persists in a long-lived latent reservoir in resting memory CD4+ T cells. These latently infected cells represent a major barrier to eradication. A prominent paradigm for HIV-1 cure involves the reactivation of viral transcription in latently infected CD4+ T cells by small molecules. Agents that elicit global T cell activation have been shown to be effective in HIV-1 latency reversal, but cannot be used in a clinical setting due to severe adverse effects associated with this strategy. Due to this toxicity, agents eliciting any level of T cell activation have been avoided in the “shock and kill” approach to eradication, significantly limiting the repertoire of compounds that can be used. The adverse response associated with immune activation is commonly attributed to massive cytokine release by T cells. However, this toxicity may be avoided using concurrent immunosuppressant treatment. The goal of this study was to identify immunomodulatory compounds that inhibit cytokine release and proliferation during a T cell activation approach, without affecting HIV-1 gene expression. Methods: Resting CD4+ T cells were isolated from HIV-1 infected individuals on effective cART treatment. Cells were treated for 24 hours with α CD3/ α CD28 stimulation only, stimulation plus rapamycin or cyclosporin, or a no treatment control. To measure reactivation of latent HIV1, cellular RNA was isolated, reverse transcribed, and qPCR was performed to specifically identify polyadenylated HIV-1 transcripts. Supernatant cytokine release and cell proliferation were assayed by flow cytometry. Results: We found that rapamycin, an mTOR inhibitor, did not inhibit HIV-1 transcriptional response to α CD3/ α CD28 stimulation at concentrations up to 5ug/ml. At these same concentrations, rapamycin was effective at inhibiting pro-inflammatory cytokine release and cell proliferation in response to this stimulation. As expected, the calcineurin inhibitor cyclosporin abrogated both cytokine release and HIV-1 expression induced by α CD3/ α CD28 treatment. Conclusions: Rapamycin downregulates toxic effects of T cell activation without affecting expression of HIV-1. These findings indicate that latency reversing agents that induce some level of T cell activation may be safely and effectively used in the presence of immunomodulators such as rapamycin. 416 Latency Reversing Agents Activate Latent Reservoirs in the Brain of SIV-Infected Macaques Lucio Gama 1 ; Sarah Price 1 ; Erin Shirk 1 ; Suzanne E. Queen 1 ; Ming Li 1 ; Brandon Bullock 1 ; StephenWietgrefe 2 ; Luiz Pianowski 3 ; M. Christine Zink 1 ; Janice Clements 1 1 Johns Hopkins University School of Medicine, Baltimore, MD, US; 2 University of Minnesota, Minneapolis, MN, US; 3 Bioqual, Valinhos, Brazil Background: Our group has been testing the PKC activator ingenol-3-hexanoate (Ing-B) as a potential candidate for a “Kick and Kill” HIV eradication strategy. Preliminary data show that Ing-B treatment caused a temporary but significant increase in plasma viral load (VL) of two virally suppressed SIVmac251-infected cART-treated rhesus macaques.

Poster Abstracts

296

CROI 2015