CROI 2015 Program and Abstracts

Abstract Listing

Poster Abstracts

seen predominantly in meninges and perivascular spaces. Few HIV-1p24+ human cells were observed. Altered MEMRI signal enhancement was readily observed in affected brain regions of infected animals. These included, but were not limited to, the hippocampus, amygdala, thalamus and cerebellum. MEMRI findings paralleled levels of infection, neuroinflammation and neuronal injury. These proved to be an accurate measure of virus-induced neuropathology. Conclusions: These MEMRI signal enhancements demonstrates the complexities of HIV-1 associated neuropathology in rodents that reflect, in measure, the clinical manifestations of neuroAIDS as it is seen in a human host. 505 Detectable CSF Tat Despite Dual Compartment HIV Viral SuppressionWith cART Bruce Brew 1 ; Lucette A. Cysique 2 ; Simon Jones 4 ;Tory Johnson 3 ; Avindra Nath 3 1 St Vincent’s Hospital, Sydney, Sydney, Australia; 2 Neuroscience Research Australia, Sydney, Australia; 3 National Institute of Neurological Disorders and Stroke, Bethesda, MD, US; 4 St Vincent’s Centre for Applied Medical Research, Sydney, Australia Background: HIV associated neurocognitive disorders (HAND) persist despite HIV suppression in both the blood and cerebrospinal fluid (CSF). Antiretroviral drugs do not prevent post integration transcription of viral components such as tat. Further, tat is known to be neurotoxic and able to exit the infected cell. We therefore hypothesized that the presence of HAND in the context of HIV suppression in both blood and CSF would be related to the presence of tat in the CSF. We further hypothesized that the putative HIV latency biomarker BCL11b would be elevated in those samples where tat was not detectable. Methods: Thirty seven CSF samples from 37 HIV+ adults (1 female) with viral suppression in both blood and CSF (<20 cpml) were assessed for the presence and amount of tat by an ELISA assay. All the patients had been assessed medically and neuropsychologically (NP) as part of an HIV and aging prospective study whose inclusion criteria were: aged 45+, CD4 nadir ≤ 350; HIV duration ≥ 5 years, ≥ 6 months cART, and exclusion were lifetime neurological and psychiatric disorders including alcohol/substance use disorder within 12 months of study entry. Using standard criteria, NP-HAND was present in 65% (Asymptomatic Neurocognitive Impairment (ANI) in 14; Mild Neurocognitive Disorder (MND) in 7; and HIV-associated dementia (HAD) in 3). CSF BCL11B was detected by immunoblot assay using anti-BCL11b antibody while levels were quantified by measuring the integrated intensity of fluorescence from the secondary conjugated antibody. Results: CSF tat was found in five of the 37 samples (range: 27-375pg/ml). There was no correlation with HAND: 3 of the 5 were NP-normal, 1 had ANI and the other had HAD. BCL11b integrated intensity levels were 0.24 ± 0.04 (mean ± sem). There was no correlation between CSF tat and BCL11b. Conclusions: CSF tat is detectable in 13.5% of dual compartment virally suppressed patients. The lack of correlation with HAND may be related to intermittent tat production, tat polymerization rendering the current assay insensitive, or other causal factors for HAND (other transcripts such as vpr,nef or drug toxicity, inactive HAND). Nonetheless, the presence of tat despite viral suppression has implications for eradication strategies especially those that involve cART. 506 DNA Methylation Changes in HIV-Positive MenWith Cognitive Decline Jeremy Martinson ; Gregory Joseph; Lawrence Kingsley; JamesT. Becker Pitt Mens Study University of Pittsburgh, Pittsburgh, PA, US Background: A subset of aging individuals with chronic, treated, HIV infection develop neurocognitive decline. Epigenetic factors, such as DNA methylation, have been implicated in the aging process and the development of chronic diseases. We hypothesize that long-term treated HIV infection has had a detectable impact on DNA methylation in these individuals, and this epigenetic change is associated with their cognitive impairment. Methods: Within the Pitt Mens Study, we identified 8 men with cognitive decline (3 seropositive and 5 seronegative), and matched themwith 8 seropositive controls (matched on age and length of time seropositive) and 8 seronegative controls (matched on age). For each of these 24 men we obtained a PBMC pellet from a recent clinic visit and an archival PBMC collected on average ten years earlier. The DNA methylation profile was then determined for each time point using the Illumina HumanMethylation450K microarray, and the change in methylation status at each of the 480,000 CpG sites present on the microarray was calculated. Results: Over the ten-year time period, DNA methylation levels changed little in any of the seropositive and seronegative control samples. In stark contrast, DNA methylation was drastically perturbed in every seropositive and seronegative sample with cognitive decline. The CpG sites affected are different in each individual: no consistent Methylation Variable Positions (MVPs) or Differentially Methylated Regions (DMRs) were found by bioinformatic analysis, and pairwise comparisons showed that the magnitude and direction of the methylation change at each site varied greatly between individuals. The perturbations were similar in both seropositive and seronegative samples, but the average age of onset of cognitive decline was 10.5 years younger in the seropositive samples. Conclusions: We determined that the development of cognitive decline in our samples is accompanied by a chaotic change in DNA methylation. This may be due to changes in the populations of cells that make up the PBMC samples obtained for each person, but it is more likely that this “methylation entropy” reflects random changes in DNA methylation in the genome of affected individuals. It is not clear what initial events trigger this chaotic change, nor is it clear how this increase in entropy affects cognition, but we suggest that DNA methylation may be a biomarker of risk for cognitive decline, and should also be investigated in other diseases of aging in HIV-positive individuals. 507 HIV Induces Astrocyte Senescence and Is Reversed by Beta-Catenin Induction Background: Neuroinflammation and neurodegeneration are hallmarks of HIV-Associated Neurocognitive Disorders (HAND). Astrocyte senescence induces neuropathologies due to increased oxidative stress and altered cytokine secretion leading to neuroinflammation. These processes reduce the neuroprotective capacity of astrocytes leading to long-term inflammation and neurodegeneration. We evaluated the impact of HIV on astrocyte senescence and explored the role of Wnt/b-catenin, a pro-survival pathway, in astrocyte senescence in the context of HIV. Methods: Human Fetal Astrocytes (HFAs) were infected with VSVG pseudotyped-HIV BAL or transfected with a full length HIV BAL plasmid (pHIV BAL ) or corresponding controls. HFAs were transfected with β -catenin siRNA, scrambled siRNA, constitutively active β -catenin plasmid (pABC), or background. Dickkopf-related protein 1 (DKK1) was used as an antagonist of the Wnt/ β -catenin pathway. Six days post treatment, HFAs were fixed and stained for senescence-associated β -galactosidase (SA- β -gal); percent positive SA- β -gal ChunjiangYu; Victoria Lutgen ; Lena Al-Harthi Rush University Medical Center, Chicago, IL, US and pHIV BAL significantly induced SA- β -gal staining in HFAs by 5- and 2-folds, respectively. β -catenin knockdown or antagonizing Wnt/b-catenin signaling through DKK-1 treatment induced SA-b-gal expression in HFA by ≥ 3.5 folds. Conversely, pABC inhibited HFA senescence by ≈ 60%. Conclusions: HIV induces astrocyte senescence. Given that we previously demonstrated that HIV diminishes b-catenin signaling in astrocytes and we show here that reduction in b-catenin expression promotes while induction of b-catenin protects against astrocyte senescence suggests that HIV induces astrocyte senescence through inhibition of b-catenin cells were recorded. Results: VSVG-HIV BAL

Poster Abstracts

334

CROI 2015