CROI 2016 Abstract eBook

Abstract Listing

Oral Abstracts

6 Deciphering Mucosal Barrier Functionality and HIV Immunity by Mass Spectrometry Adam Burgener , Univ of Manitoba, Winnipeg, MB, Canada

Advances in proteomic techniques, such as mass spectrometry, allow for an unprecedented ability to study immunological systems, by characterizing thousands of proteins simultaneously in biological samples with high sensitivity and dynamic range. Mass spectrometry can be utilized to study whole proteomes, their modifications, location, and even interactions, which has led to the growing adoption of this technology in biomedical research and furthered our understanding of human diseases and immunity. In HIV infection, mucosal immune systems are an intense area of research given the critical roles it plays in both HIV transmission and disease. Understanding mucosal immune systems has significant relevance for HIV prevention efforts and vaccine design, where their success rest upon their ability to elicit or maintain protective mucosal immunity while simultaneously avoid inflammation processes which enhance HIV susceptibility. However, mucosal immune correlates of HIV infection largely remain undefined, largely driven by comprehensive toolsets to study mucosal surfaces, of which mass spectrometry technology can afford. In this presentation, I will first introduce the mass spectrometry workflow and the opportunities this technology provides to understand complex biological samples and host immunity, with particular consideration for clinical studies. I will then provide examples relevant to the HIV field, by discussing howmass spectrometry has provided novel mechanistic insight into mucosal immune system changes associated with HIV risk factors, such as hormonal contraceptives, genital tract inflammation, and microbial dysbiosis. Finally, I will show how this can be integrated with large-scale clinical trials, by discussing our ongoing studies of proteome profiling of >800 women at high risk for HIV from South Africa (w/ CAPRISA), the generation of proteome libraries spanning thousands of host and microbial factors, and the potential this information has to understand host pathogen interactions, HIV transmission, and reproductive health. This presentation will provide a broad overview of how to incorporate mass spectrometry into clinical/lab studies, how it can be integrated with other immunological platforms (microbiome, cellular, cytokines, etc.), and how it can contribute to HIV prevention technology development and reproductive health studies for women. 7 Drop-Based Microfluidics for Single-Cell Studies David A. Weitz , Harvard Univ, Boston, MA, USA This talk will report on the use of drop-based microfluidics to investigate the behavior of single cells. The method entails the creation of small aqueous drops, each containing picoliters to nanoliters of fluid, immersed in a continuous, inert oil phase. The oil phase provides the fluidic control, enabling each drop to be manipulated and studied. The drops are the optimal size to control a single cell, or a single cell plus a second, target cell. In addition, each drop can contain an arbitrary number of viruses or other infectious agents; this number can be as small as a single virus. Interactions among the virus, the target cell and the probe cell can be probed, with all components trapped within the confines of the drop. Each drop represents an independent experiment, and up to hundreds of millions of drops can be probed in a single experiment. This enables very high throughput screening of either the probe cells or the behavior of the virus. The readout can be either optical or through bar-coded DNA, read through next generation sequencing. Alternatively, if specific cells can be identified, they can be selected and sorted from the rest of the sample for further use or analysis. This talk will explore applications of this method to probe up to millions of cells at single-cell resolution. The probes include full transcriptome measurement at single-cell resolution, viral neutralization through antibody secretion and cell-cell interactions. 8 Integration of Systems Biology with Tissue Engineering and Organs-On-Chips Linda Griffith , Massachusetts Inst of Tech, Boston, MA, USA Move over, mice! Systems biology – data-driven modeling of extracellular and intracellular communication networks linked to phenotypic outcomes at the cell, tissue, or systemic level in patients – is yielding new insights into mechanisms of HIV infection, variability in patient responses to infection, and responses to therapies. For example, CAPRISA investigators have shown a complex role for inflammation in the female reproductive tract on HIV susceptibility, with elevated levels of certain cytokines associated with barrier disruption and increased susceptibility. In vitro human tissue engineered models that recreate mucosal barrier tissues in long term culture, with the ability to probe local paracrine cytokine and growth factor networks operating between epithelia, stromal and immune cells longitudinally over time in culture, offer the potential to parse mechanisms and test efficacy of interventions. The first part of this presentation will describe approaches to recapitulate 3D barrier mucosal tissues using synthetic extracellular matrix that supports long term reconstitution of tissues and can be dissolved on demand to (a) measure communication networks via multiplex luminex-type assays and (b) release cells without alteration of cell surface proteins or disruption of cell-cell junctions; synthetic matrix approaches can be tailored to specific epithelial barriers. Such approaches work in parallel with explant cultures, allowing polarized tissues with defined compositions to be created. The second part of the presentation will address development of “organs-on-chips” approaches to analyze systemic interactions between epithelial barrier tissues (gut, reproductive tract) and the liver, with respect to how inflammation cross talk influences responses to therapeutics. Emphasis will be placed on the practical design of platforms that enable quantitative control of PK/PD of drugs and endogenous biological regulators, particularly lipophilic compounds such as sex steroids (e.g estradiol) and antiretroviral drugs, which commonly have log D values of 2-4 and thus strongly partition into the popular PDMS (silicone rubber) microfluidic systems, making alternate approaches to fluidic systems necessary for quantitative analysis. Further, challenges with designing platforms to measure inflammation crosstalk and potential applications of technologies arising from the DARPA/NIH Microphysiological Systems programwill be described. 9 Treatment for HCV Genotype 1-Infected Patients With HIV/HCV Coinfection Anne F. Luetkemeyer , Univ of California San Francisco, San Francisco, CA, USA Treatment of HCV is a priority in HIV/HCV co-infected patients due to the morbidity, mortality and potential for more rapid disease progression that HCV incurs in HIV infection. Choice of DAA treatment is complicated by drug-drug interactions with HIV antiretrovirals. This interactive session will review currently available DAA treatment options for HIV/ HCV individuals with HCV genotype 1 with attention to drug interactions and consideration of any impact that HIV infection may have on treatment duration and outcome. 10 HCV Genotype 3 Infection: Treatment for Patients With Cirrhosis and Treatment Failure Karine LaCombe , Sorbonne Univs, Paris, France Genotype 3 (GT3) HCV chronic infection has long been considered as difficult-to-treat. Mainly transmitted through intravenous drug use, GT3 HCV presents certain conformational peculiarities, rendering the activity of common direct antiviral agents less potent than other genotypes. It also negatively interacts with lipid metabolism, which increases the risk of developing steatosis and in turn has a synergistic and deleterious effect on the evolution of liver fibrosis. All these factors together explain why many GT3 HCV patients have failed previous antiviral treatments and have now reached advanced stages of liver fibrosis and cirrhosis, becoming increasingly difficult to treat. During this presentation, we will review the clinical and therapeutic history of a GT3 HCV mono-infected patient and highlight the issues that clinicians must face in care and management, including the assessment of drug-drug interactions and evaluation of liver cirrhosis before treatment and beyond cure. 11 HCV Infection Treatment Before and After Liver Transplant Elizabeth C. Verna , Columbia Univ, New York, NY, USA Hepatitis C (HCV) remains the most common indication for liver transplantation (LT) in the United States, and graft outcomes have traditionally been inferior to patients without HCV due to recurrent disease. The recent transformation in our ability to eradicate chronic HCV infection with well-tolerated, potent interferon-free regimens has dramatically changed our management of HCV before and after LT. The dramatic improvement in the efficacy and tolerability of the direct acting antiviral (DAA) agents now renders the goal of treatment for all patients with decompensated liver disease, either before or after LT, a potential reality. Treatment for cure on the LT waiting list to potentially avoid LT or to eliminate the risk of recurrent disease in the allograft would be the ideal approach if feasible and risk-free for all. In addition, data have emerged from post-LT trials revealing high

Oral Abstracts

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CROI 2016