CROI 2019 Abstract eBook

Abstract eBook

Poster Abstracts

pathogenesis was measured using multiparametric flowcytometry. Next some macaques were treated with ART starting fromweek 10 for 3 months to monitor post-treatment interruption and to evaluate viral variants. Tissues and organs including brain were evaluated using immunohistochemistry. Results: The newly generated SHIVs are replication competent and shown to be tier 2 neutralization sensitive phenotype. Animals inoculated under the depletion of JAK3 inhibitor showed persistently high viral loads in both plasma and CSF for more than 6 months. After necropsy tissues were investigated for viral loads in different tissues and organs. Next CNS tissues showed mild pathology and very few virus positive cells suggesting that mild infection to CNS. The reisolated virus was again inoculated IVAG to non-JAK treated animals and showed peak viral loads (108) and persistent viral loads up to 6 months. Next, Animals with ART treated showed virus rebounded after post treatment interruption and currently monitoring for viral set points and measuring viral variants. Conclusion: The newly generated SHIVs are replication competent in macaques, maintained viral set points for longer periods and neurotropic. These novel SHIVs will be useful tools for HIV cure studies as well as evaluating anti-HIV drugs, microbicides, and vaccine strategies. 429 EVOLVING SIV REGIONAL BRAIN INJURY AND RECOVERY ARE LINKED TO ANTIOXIDANT EXPRESSION Yoelvis Garcia-Mesa 1 , Brandon L. Bastien 1 , Rolando Garza 1 , Analise Gruenewald 1 , Michael R. Betts 1 , Guido Silvestri 2 , Dennis L. Kolson 1 1 University of Pennsylvania, Philadelphia, PA, USA, 2 Emory University, Atlanta, GA, USA Background: Brain dysfunction in HIV infection can evolve despite ART suppression. Brainstem regions, including those with dopaminergic functions, may be more vulnerable to injury, for unclear reasons. In the SIVmac251 model, we previously demonstrated regional brain differences in protective host anti- oxidant responses (heme oxygenase-1/HO-1) and we hypothesized that such differences would predict regional brain injury. To define evolving brain injury, we have now assessed neuronal markers of pre- and post-synaptic integrity and neurotransmitter phenotype in these animals, and correlated expression with oxidative response markers. Methods: Eighteen rhesus macaques (2-3 yo) infected with SIVmac251 were sacrificed 5, 10, 13, 20, 41, and 90 days post infection (dpi). Nine brain regions (midbrain, parietal, basal ganglia, medulla, pons, frontal, pre-frontal, deep frontal, and cerebellum) were analyzed by western blot for neuronal markers PSD95, SYN1, synaptophysin, and tyrosine hydroxylase (TH), and the anti- oxidant response markers, HO-1, GPX1. Statistical analyses were by two-way ANOVA, post-hoc tukey’s test, post-test for linear trend, and multivariate linear regression. Results: Acute SIV infection (13-20dpi) correlated with neuronal injury markers (decreased PSD95, synaptophysin, p<.01) and neuronal functional responses (increased SYN1, p<.05) in most brain regions (brainstem and cortical), and specific dopaminergic neuronal responses (decreased TH, p<.05) in basal ganglia. Chronic infection (40-90dpi), showed sustained, but not progressive, neuronal injury from day 20 to day 90 (no significant changes in PSD95, synaptophysin), and no changes in dopaminergic responses (TH). However, cortical regions, but not brainstem regions, did show significant increases in PSD95 from day 13 to day 90pi, which suggests possible spontaneous regional brain recovery from acute injury. In acute and chronic phases antioxidant HO-1 expression correlated with PSD95 and synaptophysin (p<.001). Conclusion: Neuronal injury in both brainstem and cortical regions occurs early in SIV infection and is sustained through chronic infection, with evidence for spontaneous recovery in cortical, but not brainstem regions. Because brainstem regions express lower antioxidant response enzymes (HO-1, GPX1) and because neuronal injury correlates negatively with HO-1 expression, our results support the hypotheses that lower brainstem antioxidant capacity accounts for brainstem vulnerability to, and less recovery from, SIV/HIV injury. 430 DOLUTEGRAVIR ACCUMULATES IN THE FETAL BRAIN FOLLOWING IN UTERO EXPOSURE Aditya N. Bade 1 , Benson Edagwa 1 , JoEllyn McMillan 1 , Gary E. Siuzdak 2 , Howard E. Gendelman 1

1 University of Nebraska Medical Center, Omaha, NE, USA, 2 The Scripps Research Institute, La Jolla, CA, USA Background: Dolutegravir (DTG)-based antiretroviral drug regimens will roll out worldwide with up to 15 million people receiving the drug within the next five years in resource-limited countries (RLCs), where most people infected with the human immunodeficiency virus (HIV) are women of child-bearing age. To this end, DTG has been shown to be highly effective due to its potent antiretroviral activities and high-barrier to viral resistance. Cautionary notes have surfaced, in recent months, regarding its safe use during pregnancy. Increased number of birth defects have emerged which warrants further investigation. Indeed, an observational study conducted in Botswana identified a potential risk of DTG in the development of neural tube defects. We recently reported that DTG crosses the blood brain barrier and can induce brain oxidative stress in adult mice. Herein, initial experiments were designed to determine whether administration of DTG to mothers could result in high levels of the drug in fetal brains. Methods: DTG was administered intramuscularly to C57BL/6 female mice every 72 hours at 45 mg/kg dose. Treatment was initiated 3 days prior to mating and continued throughout pregnancy. Treatment was stopped at the day of birth of pups. Plasma was collected from dams for DTG quantification before and during pregnancy. At post-natal day 0.5, neonatal whole brains were processed to quantitate DTG following in utero exposure by UPLC-MS/MS. Results: Plasma DTG concentrations were consistent among female mice with 13.5 µg/mL (Cmax) during pregnancy (Panel a). DTG concentrations in brains of all neonates from the same litter were similar (Panel b), averaging 114.2 ng/g. Conclusion: We conclude that placental transfer of DTG during pregnancy can result in high drug levels in fetal developing brain. With previous data in hand, we posit that such an exposure could lead to oxidative stress subsequently affecting fetal brain development. Future experiments are designed to determine such linkages.

Poster Abstracts

431 HIV BASAL-GANGLIA INJURY CORRELATES WITH ANTIOXIDANT & ENDOTHELIAL ADHESION MARKERS

Analise Gruenewald 1 , Rolando Garza 1 , Yoelvis Garcia-Mesa 1 , Patricia J. Vance 1 , Benjamin B. Gelman 2 , Dennis L. Kolson 1 1 University of Pennsylvania, Philadelphia, PA, USA, 2 University of Texas at Galveston, Galveston, TX, USA Background: Regional brain vulnerability to HIV is well-known but its determinants are not. Blood-brain barrier damage in the highly vulnerable basal ganglia correlates with cognitive impairment, suggesting vulnerability linked to endothelial dysfunction. We previously identified reduced pre-frontal cortex expression of the antioxidant heme oxygenase-1 (HO-1), as a risk for HIV encephalitis and cognitive dysfunction; in recent macaque studies we identified regional brain HO-1 variation that correlated with neuronal injury. We hypothesize that human brain HO-1 expression also varies regionally and correlates with endothelial cell adhesion molecule expression and neuronal injury in HIV. Methods: Thirteen brain regions grouped as: i) cortical: frontal, temporal, occipital, anterior and posterior cingulate, motor, and sensory cortices; ii) basal ganglia: caudate, globus pallidus; and iii) others: frontal white matter; amygdala; cerebellum; pons) were dissected from 10 autopsies (7 HIV+, 3 HIV-) provided by the National NeuroAIDS Tissue Consortium. Endothelial cell adhesion molecules (ICAM-1, VCAM-1, PECAM-1), neuronal integrity (PSD95, synaptophysin), and HO-1 were quantified (Western blot, RT-qPCR). Expression was compared by one-way ANOVA/Sidak’s correction, or two-way ANOVA/ Tukey’s correction, and Pearson’s correlation. Results: We found that brain HO-1 RNA, but not protein, varies regionally, and, in HIV+ subjects, it correlates with endothelial adhesion molecules (ICAM-1,

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