CROI 2016 Abstract eBook

Abstract Listing

Poster Abstracts

270 CD169 Is a Marker of Immune Activation in SIV Infection but Not Rectal Susceptibility

Magnus Hallor 1 ; Meropi Aravantinou 2 ; Rachel Singer 2 ; Agegnehu Gettie 3 ; James Blanchard 4 ; Jeffrey Lifson 5 ; Michael Piatak 5 ; Andres Salazar 6 ; Melissa Robbiani 2 ; Nina Derby 2 1 Linkoping Univ, Linkoping, Sweden; 2 Pop Council, New York, NY, USA; 3 Aaron Diamond AIDS Rsr Cntr, New York, NY, USA; 4 Tulane Natl Primate Rsr Cntr, Covington, LA, USA; 5 Frederick Natl Lab, Frederick, MD, USA; 6 Oncovir, Inc, Washington, DC, USA Background: CD169 is an activation marker expressed by monocytes, macrophages, and dendritic cells (DCs) under inflammatory conditions. Expression is upregulated upon HIV infection and correlates with pathogenesis. Macaque monocytes and DCs also express CD169, and blood monocyte expression correlates with viral load during SIV infection. On monocyte-derived DCs (moDCs) matured with LPS or polyIC (PIC), CD169 captures infectious HIV particles and delivers them to CD4 + T cells at the infectious synapse. Clinical grade PIC, polyICLC (PICLC), is being pursued as a vaccine adjuvant, but the implications of in vivo CD169 upregulation for HIV acquisition are not defined. Methods: We identified CD169 on rhesus macaque PBMCs by flow cytometry (anti-human CD169 mAb clones 7D2 and 7-239) and quantitative RT-PCR and within rectal tissue samples by qRT-PCR. Freshly isolated PBMCs were stained after overnight culture (2x10 6 /ml) in 10-25ug/ml PIC or PICLC vs. media. To gauge the in vivo impact of PICLC stimulation, we quantified CD169 mRNA in rectal tissues of macaques biopsied 4-24h after PICLC vs. PBS application. We also monitored rectal CD169 mRNA expression over time following wild type (WT) and attenuated (Delta Nef) SIV rectal challenge. Differences between groups were evaluated with the Mann Whitney or Wilcoxon signed rank tests. Results: Overnight culture of rhesus macaque PBMCs with PIC or PICLC increased CD169 mRNA in the PBMCs and surface protein expression on Lin-HLA-DR+CD11c+myeloid DCs. CD169 mRNA was similarly elevated in rectal tissue of PICLC-treated macaques and also in macaques infected with SIV. Comparison of WT and Delta Nef SIVmac239 infections revealed greater rectal CD169 expression in WT-infected animals in both acute and chronic infection. Baseline expression correlated with peak viremia, and expression over time correlated with plasma viral load. However, rectal CD169 level at baseline did not predict infection outcome in these animals. Conclusions: We show that CD169, an inducible receptor for infectious HIV on human DCs and a marker of viral load in HIV infection, is induced in rhesus macaques rectally by PICLC as well as SIV and correlates with SIV replication. While we confirm CD169 is a biomarker of pathogenesis, we show it is not likely to direct virus transmission across the rectal mucosa. 271 Adipose Tissue and HIV Infection Abderaouf Damouche 1 ;Thierry Lazure 2 ;Veronique Avettand-Fenoel 3 ; Nicolas Huot 4 ; Christine Rouzioux 5 ; Jacqueline Capeau 6 ; Michaela Müller-Trutwin 4 ; Nathalie Dereuddre- Bosquet 7 ; Roger Le Grand 7 ; Olivier Lambotte 8 ; Christine Bourgeois 7 1 Univ Paris Sud, UMR 1184, Ivry sur seine, France; 2 Hôpitaux de Paris, Hôpitaux Universitaires Paris-Sud, Le Kremlin-Bicêtre, France; 3 EA7327, Univ Paris Descartes, Paris, France; 4 Inst Pasteur, Paris, France; 5 Necker Hosp, AP-HP, Paris, France; 6 INSERM UMR-S 938, CDR Saint-Antoine, Paris, France; 7 Univ Paris Sud, UMR 1184, Le Kremlin-Bicêtre, Fontenay aux Roses, France; 8 Univ Paris Sud, UMR 1184, Le Kremlin-Bicêtre, France Background: Chronic immune activation/inflammation and viral persistence in reservoirs are important features of chronic HIV infection even in patients receiving ART. The aim of our work was to identify site that may combine viral persistence and inflammatory potential. We believed that adipose tissue was a very promising candidate because it included the major targets of HIV infection (CD4 T cells, and macrophages) and exhibited a highly pro-inflammatory potential. Although adipose tissue has been extensively studied as a target of antiretroviral toxicity, we readdress the role of adipose tissue as a reservoir and a site of inflammation. Methods: Adult cynomolgus macaques ( Macaca fascicularis ) were infected with simian immunodeficiency virus (SIV) SIVmac251 for 15 months. Non-SIV-infected animals were used as controls. At sacrifice, blood samples, abdominal subcutaneous adipose tissue (SCAT) and visceral adipose tissue (VAT) were collected. Phenotypic characterization of macrophages and T lymphocytes from the stromal vascular fraction (SVF) of adipose tissue were performed. SIV DNA and RNA was measured in sorted adipose CD4+ T cells and macrophages. In the second part of this work, we analyzed adipose tissue from 13 anti-retroviral therapy-treated HIV-1-infected with undetectable viral load for over four years. SVF samples fractions were screened for HIV DNA. HIV RNA detection following in vitro reactivation assay was also performed. Results: We analyzed the impact of SIV infection on abdominal SCAT and VAT in SIVmac251 infected macaques and found that both adipocytes and adipose tissue immune cells were affected. The adipocyte density was elevated and adipose tissue immune cells presented enhanced immune activation and/or pro-inflammatory profiles. We detected cell-associated SIV DNA and RNA in the SVF and in sorted CD4+ T cells and macrophages from adipose tissue. We demonstrated that SVF cells and more specifically CD4+ T cells are infected in ART-controlled HIV-infected patients. Importantly, the production of HIV RNA was detected after the in vitro reactivation of sorted CD4+ T cells from adipose tissue. Conclusions: We identified adipose tissue as a crucial cofactor in both viral persistence and chronic immune activation/inflammation during HIV infection. These observations open up new therapeutic strategies for limiting the size of the viral reservoir and decreasing low-grade chronic inflammation via the modulation of adipose tissue-related pathways. 272 a4-Integrin Antibody Blocks Monocyte Traffic and Decreases SIV Pathology in DRGs Jessica R. Lakritz 1 ; DerekThibault 1 ; Jake A. Robinson 1 ; Jennifer Campbell 1 ; Andrew D. Miller 2 ;Tricia H. Burdo 1 1 Boston Coll, Chestnut Hill, MA, USA; 2 Cornell Univ, Ithaca, NY, USA Background: Infiltration of activated immune cells into dorsal root ganglia (DRG) is a critical mechanism of pathology in HIV peripheral neuropathy. Our recent work has shown that accumulation of recruited (BrdU + MAC387 + ) monocyte/macrophages is associated with severe DRG pathology and loss of intraepidermal nerve fiber density in SIV-infected macaques. Here, we sought to block leukocyte traffic by treating animals with natalizumab, which binds to α4-integrins, a subunit of VLA-4 expressed on leukocytes. Methods: Sixteen rhesus macaques were SIV-infected and CD8-depleted. Eight animals were sacrificed early at 21 days post-infection (dpi) and eight animals were sacrificed late (49-77 dpi). 5/8 animals in the early group received natalizumab at the day of infection and 4/8 animals in the late group received natalizumab at 28 dpi. All animals received serial BrdU inoculations to label cells emigrating from the bone marrow to the tissue. Results: Histopathology showed diminished DRG pathology including decreased inflammation, neuronophagia, and Nagoette nodules in natalizumab treated groups compared to control animals. Natalizumab treatment decreased the amount of BrdU + cell traffic in early treated animals and MAC387 + monocyte influx in late-treated animals. The number of CD68 + macrophages was decreased in both early and late treated groups. The number of SIVp28 + cells in DRG tissues was also decreased in late treated animals compared to untreated controls. The number of CD3 + T cells in DRGs was not altered by early or late natalizumab treatment. VCAM-1 was detected on blood vessels in DRGs of early and late untreated animals, but was significantly diminished in DRGs of all natalizumab-treated animals. Conclusions: These data show that blocking monocyte, but not T cell traffic to the DRGs results in decreased pathology, further supporting a role for monocyte traffic and activation in HIV peripheral neuropathy. Additionally, natalizumab treatment significantly diminished the amount of SIVp28 + cells in the DRG in late treated animals suggesting that targeting monocyte traffic may prevent formation of viral reservoirs. Additionally, we have demonstrated using natalizumab in a SIV-infection model reduces VCAM- expression in the DRGs. 273 SIV-Associated Pathogenesis ModulationWith Macrophage Targeted MGBG Tricia H. Burdo 1 ; JoshuaWalker 1 ; Hua Xu 2 ; Andrew D. Miller 3 ; Michael S. McGrath 4 ; Kenneth C.Williams 1 1 Boston Coll, Chestnut Hill, MA, USA; 2 Pathologica LLC, San Francisco, CA, USA; 3 Cornell Univ, Ithaca, NY, USA; 4 Univ of California San Francisco, San Francisco, CA, USA Background: The role macrophages play as a target for HIV infection and in AIDS pathogenesis is controversial. This study used a novel oral form of a polyamine biosynthesis inhibitor MGBG (PA300), that exclusively targets activated and infected macrophages and not T cells, in a SIV infection associated pathogenesis study. Methods: Two studies were performed using SIVmac251-infected CD8-depleted rhesus macaques. The first was a 30 day pK study (0, 3, 10 and 30mg/kg/day PA300 n=2/group), and the second was a blinded longitudinal study with daily dosing of 30mg/kg for 9 weeks (untreated, n=6 and PA300 n=9). Both studies began PA300 at 21 days post-infection

Poster Abstracts

105

CROI 2016