CROI 2017 Abstract e-Book

Abstract eBook

Oral Abstracts

69 CNS PARENCHYMA AND CHOROID PLEXUS, NOT CSF, ARE VIRAL RESERVOIRS IN MONKEYS WITH AIDS Jaclyn Mallard 1 , Brittany Rife 2 , Emily Papazian 1 , Arianna Noggle 1 , David J. Nolan 2 , Marco Salemi 2 , Kenneth C. Williams 1 1 Boston Coll, Chestnut Hill, MA, USA, 2 Univ of Florida, Gainesville, FL, USA

Background: HIV-associated neurocognitive disorders (HAND) are characterized by accumulation of monocyte/macrophages (Mo/MΦ) and virus in central nervous system (CNS). While T cells and Mo/MΦ can enter the CNS from the cerebrospinal fluid (CSF) via the choroid plexus (CP) or the blood-brain barrier at the meninges, it is thought that Mo/MΦ traffic seeds CNS reservoirs as they are the predominant cell type found in parenchymal tissues. In live humans, the CSF is the only compartment that can be sampled for CNS virus. Because T cells can traffic through the CSF, and T cells and macrophages are found in the choroid plexus that makes the CSF, we hypothesized that the CSF has a mixture virus found in CNS, plasma, Mo/MΦ, T cell derived sequences and the CP has compartmentalized virus that is found in the CNS parenchyma that is a viral reservoir. Methods: Brain, CP, CSF, plasma, and T cells and Mo/MΦ from blood from 19 SIVmac251-infected and 2 uninfected rhesus macaques (11 CD8-depleted and 10 non-depleted) were assessed. SIV+ animals included: 4 without AIDS, 6 with AIDS and SIVE and 9 with AIDS without SIVE (SIVnoE). Double label in situ hybridization and immunohistochemistry was used to count SIV-infected T cells and Mo/MΦ in CP. Maximum Likelihood phylogenetic trees were constructed with SIV gp120 cDNA sequences that were isolated from the CSF, CP, CNS parenchyma and CD3+ T cells and CD14+Mo/MΦ in blood. Phylogeographic analysis of SIV sequences was used to assess compartmentalization of virus to determine tissue and cellular sources of viral reservoirs. Results: There were increased numbers of Mo/MΦ, but not T cells in CP from SIVE compared to SIVnoE animals. Mo/MΦ and T cells in the CP were SIV-RNA+. CSF viral sequences were dispersed between CNS and peripheral (plasma, bone marrow, Mo/MΦ, T cells) sequences. In SIVE animals, CP and CNS parenchymal sequences clustered together and were highly compartmentalized, indicating that these tissues are sources of CNS viral reservoirs. Conclusion: The detection of SIV-RNA+ T cells and Mo/MΦ in CP underscores the CP as a source of CSF virus. The dispersed phylogeny of CSF viral sequences among peripheral and CNS sequences indicates that the CSF is not a viral reservoir. Mo/MΦ accumulation and compartmentalization of viral sequences in the CP and CNS suggests infected Mo/MΦ in these tissues are the source of CNS viral reservoir. 70 EARLY MACROPHAGE-INDEPENDENT INFLAMMATION AND SHIV-RNA IN CNS IN A RHESUS SHIV MODEL Denise C. Hsu 1 , Piyanate Sunyakumthorn 2 , MatthewWegner 2 , Jacob D. Estes 3 , Claire Deleage 3 , Robert J. O’Connell 2 , Victor Valcour 4 , Serena Spudich 5 , Nelson L. Michael 6 , Sandhya Vasan 1 1 US Military HIV Rsr Prog, Bangkok, Thailand, 2 Armed Forces Rsr Inst of Med Scis, Bangkok, Thailand, 3 Frederick Natl Lab for Cancer Rsr, Leidos Biomed Rsr Inc, Frederick, MD, USA, 4 Univ of

Oral Abstracts

California San Francisco, San Francisco, CA, USA, 5 Yale Univ, New Haven, CT, USA, 6 US Military HIV Rsr Prog, Silver Spring, MD, USA Background: Neurologic symptoms occur and HIV RNA is detectable in CSF during acute HIV infection. We developed a non-accelerated rhesus macaque model to characterize these earliest changes in an effort to inform reservoirs and cure trials. Methods: Macaques were infected with a single SHIV1157ipd3N4 challenge intrarectally (9 males) or intravaginally (3 females). Biomarkers of immune activation were measured by Luminex at week (W)2 and W12 post infection in plasma and W12 in CSF. At W12 necropsy, brain sections from 6 SHIV+ and 6 uninfected control animals were stained with anti-CD3, CD4, and CD68 antibodies by immunohistochemistry (IHC). SHIV-infected cells were detected using RNAscope in situ hybridization. Results: SHIV RNA was detectable in CSF (lower limit of detection of the assay is 10 copies/mL) at W12 in the 4 animals with the highest W12 plasma viral load, but not in those with plasma SHIV RNA <490 copies/mL. CSF MCP-1 and IP-10 were elevated versus control CSF (284 vs 126 pg/mL, p=0.030; 282 vs 117 pg/mL, p=0.004). The W12 CSF/serum albumin ratio was <5x10-3 in all animals, consistent with an intact blood brain barrier. IHC revealed no evidence of CD68+ or CD4+ cell inflammatory infiltrate in midbrain, frontal cortex, or basal ganglia. Some SHIV-infected animals had evidence of a mild CD3+ T cell infiltrate with qualitative pavementing along the vascular endothelium and clustering in the brain parenchyma (Fig 1). However, in the meninges, CD4+ T cells were increased in a subset of SHIV- infected animals vs controls, in the absence of CD68+ cells. Rare SHIV RNA positive cells were detectable in the cortex and/or meninges in 5 out of 6 SHIV-infected animals using RNAscope staining by both IHC and immunofluorescence. In the one animal where no SHIV RNA was detected, viral load was also undetectable in CSF and was low in plasma (18 copies/mL) at W12.

Conclusion: CSF SHIV RNA and IP-10 and MCP-1 elevations reflect a discrete neurovirologic process in early infection. This is accompanied by a mild CD3+, CD4- infiltrate in the brain parenchyma and CD4+ T cells in the meninges in the absence of macrophages, and rare but distinct SHIV-infected cells in the brain cortex. Thus the earliest stages of SHIV infection are characterized by a T-cell mediated process, which is distinct from the SIV model but closely mimics findings in early HIV infections in humans. The SHIV1157ipd3N4 non-accelerated challenge model can serve as a model for future interventional studies. 71 DEEP SEQUENCING REVEALS RARE CNS COMPARTMENTALIZATION IN ACUTE HIV-1 INFECTION Rujipas Sirijatuphat 1 , James L. Fletcher 2 , Eric Sanders-Buell 3 , Jintanat Ananworanich 3 , Nelson L. Michael 3 , Victor Valcour 4 , Sodsai Tovanabutra 3 , Gustavo Kijak 3 , Serena Spudic h 5 , for the RV254/SEARCH 010 Team and MHRP Viral Sequencing Core 1 Mahidol Univ, Bangkok, Thailand, 2 South East Asia Rsr Collab with Hawaii (SEARCH), Bangkok, Thailand, 3 US Military HIV Rsr Prog, Silver Spring, MD, USA, 4 Univ of California San Francisco, San Francisco, USA, 5 Yale Univ, New Haven, CT, USA Background: HIV-1 compartmentalization plays an important role in viral pathogenesis and is considered a potential obstacle for HIV-1 cure. Viral compartmentalization has been detected in the CNS during early (> 4 months of infection) and chronic HIV, but the timing of the onset of CNS compartmentalization remains unknown. Using single genome amplification (SGA), we have found no significant compartmentalization in acute HIV-1 infection (AHI) in the Thai RV254/SEARCH010 cohort. Here, we employed targeted deep sequencing (TDS) with increased power to detect minor viral variants to evaluate HIV-1 compartmentalization between CSF and plasma during AHI. Methods: Thirteen antiretroviral-naïve acutely infected RV254/SEARCH010 participants (Fiebig stages: II=3; III=6; IV=3; V=1) were selected (criteria: availability of paired plasma and CSF samples, with CSF HIV-1 RNA levels>10 4 log 10 copies/ml). We studied the Protease (PR) and Reverse Transcriptase (RT) regions in paired CSF and plasma (median sampling interval: 1 day; range: 0-9), using the IonTorrent PGM platform, with a lower limit of detection for minor variants of 0.5%. Frequencies of single nucleotide variants and haplotypes were determined with the Nautilus pipeline. Results: All of the participants (median: 22 days post estimated infection) were infected with HIV-1 CRF01_AE. A low-level of polymorphisms was detected in plasma and CSF (median 0.8%; range 0.5-10%). TDS analysis revealed that 5 participants were infected with multiple transmitted/founder (T/F) viruses; the remainder were infected with a single T/F virus. In one participant with multiple T/F infection (RV254_276; Fiebig II, sampling interval: 1 day) a minor T/F variant circulating in plasma at low frequencies (15-23%) was

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CROI 2017