CROI 2018 Abstract eBook

Abstract eBook

Poster Abstracts

Background: Infection of CD4 T cells with HIV-1 can lead to cell death through a variety of mechanisms, however, this is counterintuitive to the observation that certain HIV-1-infected cells possess a remarkable long-term stability and can persist for decades in infected individuals treated with suppressive antiretroviral therapy (ART). The mechanisms that maintain such long-term survival of HIV-1-infected CD4 T cells are unknown at present, but may represent important targets for clinical strategies to reduce the viral reservoir. Methods: CD4 T cells were ex-vivo infected with single or dual-reporter HIV-1, followed by protein expression profiling using comprehensive mass spectrometry and flow cytometry. Molecular profiles of viral reservoirs in sorted CD4 T cell subsets were analyzed using single-genome, near full-length next generation viral sequencing. Functional in vitro assays were performed to analyze effects of small molecule inhibitors of BIRC5 on HIV-1 reservoirs in in vitro and in vivo infected CD4 T cells. Results: Proteomic analyses of HIV-1-infected CD4 T cells identified distinct signatures of cell survival in HIV-1-infected CD4 T cells that were governed by BIRC5, a member of the inhibitor of apoptosis protein family. BIRC5 and its upstream regulator OX40, a member of the TNF receptor superfamily, were upregulated in productively and latently infected CD4 T cells, and were functionally involved in maintaining their viability, specifically during times of transitioning from productive infection to viral latency. Moreover, OX40- expressing memory CD4 T cells sorted from ART-treated patients were strongly enriched for sequence-intact HIV-1, including clonally-expanded intact proviral sequences. Pharmaceutical inhibition of BIRC5 significantly decreased the frequency of productively and latently in vitro HIV-1-infected CD4 T cells, and diminished the number of patient-derived, in vivo infected CD4 T cells encoding for intact HIV-1 during ex-vivo culture. Conclusion: Our data show that productive and latent HIV-1 infection of CD4 T cells can activate cellular survival programs directed by the BIRC5/OX40 pathway. In addition, BIRC5/OX40 seem to protect HIV-1-infected CD4 T cells during the vulnerable phase of clonal expansion, a process known to contribute to viral reservoir stabilization. Targeting BIRC5 may represent a promising strategy to reduce the pool of viral reservoir in clinical settings. 369 HIV-2 RESERVOIR DISTRIBUTION IN CD4 T CELLS RELATED TO CXCR6 AND TRIM-5 EXPRESSION Assia Samri 1 , Charlotte Charpentier 2 , Mélanie Bertine 2 , Mariama S. Diallo 1 , Sophie Even 1 , Veronique Morin 1 , Anne Oudin 1 , Gilles Collin 2 , Sophie Matheron 2 , Rodolphe Thiébaut 3 , Rima Zoorob 1 , Brigitte Autran 1 , Francoise Brun-Vezinet 2 1 INSERM, Paris, France, 2 University Paris Diderot, Paris, France, 3 INSERM, Bordeaux, France Background: HIV-2 infection is characterized by a low pathogenicity and a low virus production compared to HIV-1. We tested the hypothesis of a limited distribution of the HIV-2 reservoir among central-memory CD4 T cells, as in HLA-B*27/57 elite controllers or in models of non pathogenic SIV infection, and analyzed the mechanisms involved. Methods: 14 ARV-naïve patients with long term non-progressive infection from the ANRS-CO5 HIV-2 cohort were prospectively included. Plasma viral load was <40 c/mL in 12/14 and above 1 c/mL in 4/12 [IQR=1-12]. HIV-2 inducibility was tested by CD8neg T cells culture with anti-CD3+CD28+IL-2+IL-7 for 30 days. Subpopulations were sorted in CD3-CD4+monocytes, resting naïve (N), central (C), transitional (T) and effector-memory (EM) CD4+ T cells. Cell- associated HIV-2 total DNA was quantified using a real-time PCR assay (LOD=3 c/PCR, LOQ=6 c/PCR). We analyzed the surface markers and the microfluidic c/106 PBMC [IQR=1.53-2.13]. Virus was inducible in CD8neg T cells from 3 patients. In sorted CD4+ subsets, HIV-2 DNA was undetectable in monocytes but detectable in TN, TCM, TTM and TEM from 3, 12, 9 and 10 patients, respectively. HIV-2 DNA was above the quantification threshold in TTM from only 4 patients (median=2.25 [IQR: 1.99-2.94] log 10 c/106 cells) while in TCM from only 1 patient (1.75 log 10 c/106 cells). The HIV-2 DNA levels in TTM were positively correlated to those in PBMC (p=0.008; r=0.67). There was no decrease in CCR5 cell surface expression both ex vivo and in culture. Transcriptome analysis revealed an increased expression of CXCR6 and IL22 genes in TTM compared to TCM (p= 0.023 and p= 0.037) contrasting with increased Trim5 and TP53 transcripts in TCM compared to TTM (p= 0.012 and p= 0.024). transcriptomic profile of sorted subsets related to different pathways (restriction factors, co-receptors, inflammation, chemokine….). Results: Median total HIV-2 DNA was 1.94 log 10

Conclusion: Overall, these low circulating HIV-2 reservoirs were mainly distributed in TTM, confirming the hypothesis of a limited reservoir in TCM and supporting the concept of the relative protection of TCM cells as an attribute of low pathogenicity models of HIV/SIV infection. Furthermore, the increased expression of CXCR6, described as an HIV-2 alternative co-receptor, in TTM and the increased expression of Trim5, a restriction factor limiting SIV infection, in TCM could explain the preferential distribution of HIV-2 reservoirs in TTM from these non-progressors. 370 EFFECTOR MEMORY T CELLS CONTRIBUTE TO X4 MONOTYPIC RESIDUAL PLASMA VIRUS PRODUCTION Hadega Aamer 1 , Sherry McLaughlin 1 , Michael Dapp 2 , Sheila Styrchak 1 , Ana Gervassi 3 , Janine Maenza 2 , Ann Collier 2 , James Mullins 2 , Lisa Frenkel 1 1 Seattle Children’s Research Institute, Seattle, WA, USA, 2 University of Washington, Seattle, WA, USA, 3 Center for Infectious Disease Research, Seattle, WA, USA Background: Although antiretroviral therapy (ART) can limit HIV replication to below the limit of detection, individuals with suppressed replication experience residual viremia. Residual virus is comprised predominately of monotypic viruses, but the cellular origin of this residual plasma virus and whether specific viral variants persist over time on ART is unknown. We aimed to: 1) characterize the dynamics of residual plasma viremia variants over time in chronically infected, long-term suppressed individuals; and 2) decipher the cellular origin of the residual plasma virus by evaluating proviral integration sites (IS) in immune cell subsets. We hypothesized that infected proliferating cells that persist during prolonged ART will consist primarily of effector memory T (Tem) cells and that these cells contribute to the monotypic residual viremia. Methods: Plasma viral RNA from several time points of 1 chronically infected subject with an undetectable viral load was subjected to single genome amplification of the C2V5 env region. Sequences were assembled into a maximum likelihood phylogenetic tree. Leukapheresis specimens collected after 6yrs of suppressive ART were cell-sorted into naïve, central memory, and Tem cells. HIV IS were identified from sorted cells using multiple displacement amplification-integration site looping assay. The proviral C2V5 env sequence linked with IS were used to compare to plasma C2V5 sequences to identify the potential cellular origin of plasma virus during ART. Results: Preliminary findings reveal residual plasma viremia was dominated by a large cluster of monotypic, CXCR4-tropic virions that persisted for at least 3 years of ART. Upon IS analysis of sorted cells, a link was found between this monotypic cluster and a provirus in Tem cells integrated in MLLT3. This gene is responsible for transcriptional elongation in the absence of HIV Tat. HIV integration and dysregulation of MLLT3 may enable the low-level production of residual monotypic virions detected in plasma over time on ART. Conclusion: We found peripheral Temmay contribute to monotypic plasma virus during ART, with the provirus persisting for at least 3yrs. Ongoing studies will examine the genome integrity of this provirus. These findings reveal the potential contribution of peripheral Tem in contributing to HIV persistence during successful ART. Further characterization of integration sites in immune cells will elucidate the potential biological pathways manipulated by HIV to allow persistence during ART. Rosalie Ponte 1 , Franck P. Dupuy 1 , Zabrina Brumme 2 , Natalie Kinloch 2 , Art Poon 3 , Pierre Brassard 4 , Maud Bélanger 4 , VikramMehraj 1 , Reina Bendayan 5 , Mohammad-Ali Jenabian 6 , Jean-Pierre Routy 1 1 McGill University Health Centre Research Institute, Montreal, QC, Canada, 2 Simon Fraser University, Burnaby, BC, Canada, 3 Western University, London, ON, Canada, 4 GRS Montreal, Montreal, QC, Canada, 5 University of Toronto, Toronto, ON, Canada, 6 Université du Québec à Montréal, Montreal, QC, Canada Background: The identification of cellular and anatomic HIV-1 reservoirs constitutes a priority towards a cure. In testis, we demonstrated that the immune privilege is orchestrated by myeloid cells, in part through the production of IDO and induction of suppressive CD39+ Treg. Herein, we hypothesized that the suppressive testicular environment favors local HIV persistence and compartmentalization by promoting the exhaustion/anergy of effector T cells. Therefore, we assessed the expression of T cell exhaustion markers such as PD-1/TIGIT/LAG-3, which have been correlated with HIV reservoir size in the blood, along with their respective ligands PD-L1/CD155/ HLA-DR and activation/maturation markers in macrophages (M ɸ ) and dendritic cells (DC). 371 TESTICULAR IMMUNE PRIVILEGE AND HIV-1 PERSISTENCE

Poster Abstracts

CROI 2018 129