CROI 2019 Abstract eBook

Abstract eBook

Poster Abstracts

Conclusion: We found a dose-dependent relationship between death during follow up and HAND at baseline. This is the first study of mortality and HAND in a resource-limited setting in the ART era. Our results suggest that early initiation of ART, prior to progression in HAND stage with advanced immunosuppression, may reduce mortality.

and compare infected cell frequency and cellular activation status to that observed in peripheral blood and lymph nodes. Methods: Rhesus macaques (n=18) were infected intrarectally with a subtype C, HIV-1 env SHIV (1157ipd3N4). CSF, peripheral blood, and lymph node mononuclear cells (PBMC and LNMC) were analyzed at weeks 2-12 post-infection (PI). CD4 and CD8 T cells and macrophages were sorted, using flow cytometry, from each specimen directly ex vivo. SHIV RNA+ cells were identified by RT-qPCR assays specific for unspliced (gag) and spliced (env) viral RNA. Infected cell frequency was estimated by Poisson distribution statistics for PBMC and LNMC or assigning one infected cell to positive CSF replicates. Markers of cellular activation were measured by flow cytometry (surface staining) and gene expression (RT-qPCR). Results: CSF specimens yielded an average 620 (120-2,840) CD4 T cells and 130 (2-400) macrophages after sorting. Infected, transcriptionally active (env+gag+) CD4 T cells were detected within the CSF in 25% of animals 4 weeks PI and 12% 12 weeks PI. In animals with SHIV RNA+ CSF CD4 T cells, infected (gag or env RNA+, respectively) CD4 T cell frequency was similar across CSF (0.05-2%, 0.3-1%), PBMC (0.02-7%, 0.02-2%), and LNMC (0.03-2%, 0.06-0.09%), indicating comparable T cell infection rates in these compartments in early infection (Figure 1). CSF blood contamination was minimal by ELISA and distinct cell composition. While macrophage infection was less frequently observed in CSF, the limited number of these cells constrained sampling depth. Surface expression of CD38 was elevated on CD4 and CD8 T cells in both PBMC and CSF during acute SHIV compared to uninfected controls (p<0.05). In contrast, the monocyte activation marker CD169, as well as CD38, was elevated on monocytes in PBMC (p<0.05) but not CSF, indicating T cell but not monocyte activation in CSF during acute infection. CSF CD4 T cells and macrophages both upregulated CXCL10 compared to uninfected controls and therefore might contribute to early CSF inflammation. Conclusion: Our data supports a model of productive CD4 T cell infection within the CNS during acute HIV/SHIV infection, distinct from the role of macrophages in end-stage neuroencephalitis.

426 ANEMIA AND NEUROCOGNITIVE IMPAIRMENT: A LONGITUDINAL MULTICOHORT STUDY Oluwakemi Okwuegbuna 1 , Asha R. Kallianpur 2 , Jennifer Iudicello 3 , Ajay Bharti 1 , Ronald J. Ellis 1 , Allen McCutchan 1 , Scott L. Letendre 1 1 University of California San Diego, San Diego, CA, USA, 2 Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA, 3 University of California San Diego, La Jolla, CA, USA Background: Anemia in persons living with HIV (PLWH) may occur from multiple causes and has been identified as a predictor of morbidity and mortality. Prior studies identified associations between anemia and worse neurocognitive (NC) performance in PLWH, but most studies have been cross- sectional and were not limited to those taking antiretroviral therapy (ART). This study compared erythrocyte and anemia biomarkers to NC performance over time in a large cohort of PLWH taking ART. Methods: We evaluated 1,338 participants frommultiple neuroHIV cohorts in San Diego, all on ART and followed for a mean of 29.5 months. Demographic and medical characteristics, including hemoglobin and erythrocyte indices, were collected. Anemia was defined as hemoglobin concentration of <14.0 g/dl in men and <12.0 g/dl in women, macrocytosis as mean corpuscular volume> 99fL. NC performance was assessed using demographically adjusted domain and global T scores. Statistical methods included linear regression and mixed effects modeling. Results: At baseline, participants were mostly middle aged (mean 43 years), men (77.8%), of European (54.9%), Hispanic (23.9%) or African (16.7%) ancestry. Most (69.8%) had undetectable viral load; the median nadir CD4+ cell count was 206 cells/µL; and 18.8%were currently on zidovudine. 297 (22.3%) were anemic. Anemia (p<0.0001) and macrocytosis (p=0.07) were associated with worse NC performance at baseline (model p<0.0001). Anemia remained significant (p= 0.02) on multivariate analysis. Anemia was specifically associated with worse NC performance in speed of information processing (p<0.01), recall (p=0.04), working memory (p<0.01) and motor speed (p<0.01) with trends in executive function (p=0.06) and learning (p=0.08). Over time, lower hemoglobin concentration (p<0.0001) was associated with worse global T scores (model p <0.0001). Adjusting models for covariates, including age, sex, CD4+ count and HIV RNA did not weaken this association. mitochondrial dysfunction which is implicated in pathogenesis of neurological decline. Diagnosis of anemia is relatively easy; prompt and adequate treatment may prevent or improve the severity of NC deficit. 427 SHIV GENE EXPRESSION IN CSF CD4 T CELLS DURING ACUTE INFECTION OF RHESUS MACAQUES Vishakha Sharma , Matthew Creegan, Sandhya Vasan, Michael A. Eller, Diane Bolton Henry M Jackson Foundation, Silver Spring, MD, USA Background: The origin and extent of viral replication within the CNS during early HIV-1 infection remains unclear. We aimed to assess cerebral spinal fluid (CSF) for host cells actively transcribing virus in acutely SHIV infected macaques Conclusion: Anemia and macrocytosis are associated with worse NC performance over time in PLWH on ART. Macrocytosis is an indicator of

Poster Abstracts

428 IN VIVO REPLICATION AND NEUROPATHOGENESIS OF T/F CLADE C SHIVs Debashis Dutta 1 , Srijayaprakash Uppada 1 , Olwenyi A. Omalla 1 , Lindsey A. Knight 1 , Kabita A. Pandey 1 , Samuel A. Johnson 1 , Celia C. Lebranche 2 , David C. Montefiori 2 , Siddappa N. Byrareddy 1 1 University of Nebraska Medical Center, Omaha, NE, USA, 2 Duke University, Durham, NC, USA Background: Several substantial vaccine efforts against HIV-1 have so far failed primarily because to date we have failed to identify the correlates of protective immunity and the optimal vaccine formulation that can induce such protective immune responses in vivo. The knowledge that only select single or limited virus species are transmitted via the mucosal route has advanced the concept of transmitter/founder (T/F) viruses that are preferentially transmitted should be the target of HIV vaccine. Therefore, we developed T/F SHIVs using env of HIV molecular clones from Zambian transmission pairs. Methods: Env gene of HIV3618MTF was cloned in to SHIVAD8-EO using In-Fusion cloning, named SHIV-4MTF.tS. To enhance macaque CD4 binding, we introduced N375 mutation. New SHIVs were transfected to 293T cells and supernatant was used to infect macaque PBMCs to generate virus stock. Viruses were inoculated via intra-vaginally (IVAG) route under the temporarily ablation of NK cells using JAK3 inhibitor. Sample collection was carried out (blood, CSF, RB, CVL, LN and feces) on various time points. Immune dynamics and degree of

CROI 2019 155