Interrupting Antiretroviral Treatment in HIV Cure Research: Scientific and Ethical Considerations

Over the past several years there has been intense activity directed at the possibility of achieving remission or eradication of HIV infection. Current assays for the measurement of latent HIV are insufficient to demonstrate complete clearance of replication-competent HIV. Therefore, the ultimate test for assessing whether investigational interventions have resulted in HIV remission or eradication is to interrupt standard antiretroviral therapy (ART) in a carefully controlled clinical trial setting. These procedures, known as analytic treatment interruptions (ATIs), raise important scientific and ethical questions. The lack of definitive assays for measuring viral reservoirs not only makes research on HIV remission or cure challenging, it also affects the ability to assess risks from ATIs themselves. In spite of these challenges, basic ethical criteria can be met with careful study design and close monitoring. In this brief report we outline ethical standards for HIV cure research involving ATIs. These criteria should be revisited as the science evolves

The Chicken Yolk Sac IgY Receptor, a Mammalian Mannose Receptor Family Member, Transcytoses IgY across Polarized Epithelial Cells

In mammals the transfer of passive immunity from mother to young is mediated by the MHC-related receptor FcRn, which transports maternal IgG across epithelial cell barriers. In birds, maternal IgY in egg yolk is transferred across the yolk sac to passively immunize chicks during gestation and early independent life. The chicken yolk sac IgY receptor (FcRY) is the ortholog of the mammalian phospholipase A2 receptor, a mannose receptor family member, rather than an FcRn or MHC homolog. FcRn and FcRY both exhibit ligand binding at the acidic pH of endosomes and ligand release at the slightly basic pH of blood. Here we show that FcRY expressed in polarized mammalian epithelial cells functioned in endocytosis, bidirectional transcytosis, and recycling of chicken FcY/IgY. Confocal immunofluorescence studies demonstrated that IgY binding and endocytosis occurred at acidic but not basic pH, mimicking pH-dependent uptake of IgG by FcRn. Colocalization studies showed FcRY-mediated internalization via clathrin-coated pits and transport involving early and recycling endosomes. Disruption of microtubules partially inhibited apical-to-basolateral and basolateral-to-apical transcytosis, but not recycling, suggesting the use of different trafficking machinery. Our results represent the first cell biological evidence of functional equivalence between FcRY and FcRn and provide an intriguing example of how evolution can give rise to systems in which similar biological requirements in different species are satisfied utilizing distinct protein folds

Telomerase Inhibition Targets Clonogenic Multiple Myeloma Cells through Telomere Length-Dependent and Independent Mechanisms

Plasma cells constitute the majority of tumor cells in multiple myeloma (MM) but lack the potential for sustained clonogenic growth. In contrast, clonotypic B cells can engraft and recapitulate disease in immunodeficient mice suggesting they serve as the MM cancer stem cell (CSC). These tumor initiating B cells also share functional features with normal stem cells such as drug resistance and self-renewal potential. Therefore, the cellular processes that regulate normal stem cells may serve as therapeutic targets in MM. Telomerase activity is required for the maintenance of normal adult stem cells, and we examined the activity of the telomerase inhibitor imetelstat against MM CSC. Moreover, we carried out both long and short-term inhibition studies to examine telomere length-dependent and independent activities.Human MM CSC were isolated from cell lines and primary clinical specimens and treated with imetelstat, a specific inhibitor of the reverse transcriptase activity of telomerase. Two weeks of exposure to imetelstat resulted in a significant reduction in telomere length and the inhibition of clonogenic MM growth both in vitro and in vivo. In addition to these relatively long-term effects, 72 hours of imetelstat treatment inhibited clonogenic growth that was associated with MM CSC differentiation based on expression of the plasma cell antigen CD138 and the stem cell marker aldehyde dehydrogenase. Short-term treatment of MM CSC also decreased the expression of genes typically expressed by stem cells (OCT3/4, SOX2, NANOG, and BMI1) as revealed by quantitative real-time PCR.Telomerase activity regulates the clonogenic growth of MM CSC. Moreover, reductions in MM growth following both long and short-term telomerase inhibition suggest that it impacts CSC through telomere length-dependent and independent mechanisms

Recommendations for analytical antiretroviral treatment interruptions in HIV research trials: report of a consensus meeting

Analytical antiretroviral treatment interruption (ATI) is an important feature of HIV research, seeking to achieve sustained viral suppression in the absence of antiretroviral therapy (ART) when the goal is to measure effects of novel therapeutic interventions on time to viral load rebound or altered viral setpoint. Trials with ATIs also intend to determine host, virological, and immunological markers that are predictive of sustained viral control off ART. Although ATI is increasingly incorporated into proof-of-concept trials, no consensus has been reached on strategies to maximise its utility and minimise its risks. In addition, differences in ATI trial designs hinder the ability to compare efficacy and safety of interventions across trials. Therefore, we held a meeting of stakeholders from many interest groups, including scientists, clinicians, ethicists, social scientists, regulators, people living with HIV, and advocacy groups, to discuss the main challenges concerning ATI studies and to formulate recommendations with an emphasis on strategies for risk mitigation and monitoring, ART resumption criteria, and ethical considerations. In this Review, we present the major points of discussion and consensus views achieved with the goal of informing the conduct of ATIs to maximise the knowledge gained and minimise the risk to participants in clinical HIV research

Polymorphisms in the Estrogen Receptor 1 and Vitamin C and Matrix Metalloproteinase Gene Families Are Associated with Susceptibility to Lymphoma

BACKGROUND: Non-Hodgkin lymphoma (NHL) is the fifth most common cancer in the U.S. and few causes have been identified. Genetic association studies may help identify environmental risk factors and enhance our understanding of disease mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: 768 coding and haplotype tagging SNPs in 146 genes were examined using Illumina GoldenGate technology in a large population-based case-control study of NHL in the San Francisco Bay Area (1,292 cases 1,375 controls are included here). Statistical analyses were restricted to HIV- participants of white non-Hispanic origin. Genes involved in steroidogenesis, immune function, cell signaling, sunlight exposure, xenobiotic metabolism/oxidative stress, energy balance, and uptake and metabolism of cholesterol, folate and vitamin C were investigated. Sixteen SNPs in eight pathways and nine haplotypes were associated with NHL after correction for multiple testing at the adjusted q<0.10 level. Eight SNPs were tested in an independent case-control study of lymphoma in Germany (494 NHL cases and 494 matched controls). Novel associations with common variants in estrogen receptor 1 (ESR1) and in the vitamin C receptor and matrix metalloproteinase gene families were observed. Four ESR1 SNPs were associated with follicular lymphoma (FL) in the U.S. study, with rs3020314 remaining associated with reduced risk of FL after multiple testing adjustments [odds ratio (OR) = 0.42, 95% confidence interval (CI) = 0.23-0.77) and replication in the German study (OR = 0.24, 95% CI = 0.06-0.94). Several SNPs and haplotypes in the matrix metalloproteinase-3 (MMP3) and MMP9 genes and in the vitamin C receptor genes, solute carrier family 23 member 1 (SLC23A1) and SLC23A2, showed associations with NHL risk. CONCLUSIONS/SIGNIFICANCE: Our findings suggest a role for estrogen, vitamin C and matrix metalloproteinases in the pathogenesis of NHL that will require further validation

Randomized clinical trial to assess the impact of the broadly neutralizing HIV-1 monoclonal antibody VRC01 on HIV-1 persistence in individuals on effective ART

Background. Broadly neutralizing monoclonal antibodies (bnMAbs) may promote clearance of HIV-1-expressing cells through antibody-dependent cell-mediated cytotoxicity. We evaluated the effect of the CD4-binding site bnMAb, VRC01, on measures of HIV-1 persistence in chronically infected individuals. Methods. A5342 was a phase 1, randomized, double-blind, placebo-controlled, parallel-arm study. Participants on effective antiretroviral therapy (ART) were randomized to receive 2 infusions of VRC01 (40 mg/kg) at entry and week 3, and 2 infusions of placebo (saline) at weeks 6 and 9; or 2 infusions of placebo at entry and week 3, and 2 infusions of VRC01 at weeks 6 and 9. Results. Infusion of VRC01 was safe and well tolerated. The median fold-change in the cell-associated HIV-1 RNA/DNA ratio from baseline to week 6 was 1.12 and 0.83 for the VRC01 and placebo arms, respectively, with no significant difference between arms (P = .16). There were no significant differences in the proportions with residual plasma viremia ≥1 copies/mL or in phorbol 12-myristate 13-acetate/ionomycin-induced virus production from CD4+ T cells between arms (both P &gt; .05). Conclusions. In individuals with chronic HIV-1 infection on ART, VRC01 infusions were safe and well tolerated but did not affect plasma viremia, cellular HIV-1 RNA/DNA levels, or stimulated virus production from CD4+ T cells