Background: The integration of HIV-1 DNA into cellular chromatin is required for high levels of viral gene expression and for the production of new virions. However, the majority of HIV-1 DNA remains unintegrated and is generally considered a replicative dead-end. A limited amount of early gene expression from unintegrated DNA has been reported, but viral replication does not proceed further in cells which contain only unintegrated DNA. Multiple infection of cells is common, and cells that are productively infected with an integrated provirus frequently also contain unintegrated HIV-1 DNA. Here we examine the influence of an integrated provirus on unintegrated HIV-1 DNA (uDNA).

Marine and freshwater mussels are notorious foulers of natural and manmade surfaces, secreting specialized protein adhesives for rapid and durable attachment to wet substrates. Given the strong and water-resistant nature of mussel adhesive proteins, significant potential exists for mimicking their adhesive characteristics in bioinspired synthetic polymer materials. An important component of these proteins is L-3,4-dihydroxylphenylalanine (DOPA), an amino acid believed to contribute to mussel glue solidification through oxidation and crosslinking reactions. Synthetic polymers containing DOPA residues have previously been shown to crosslink into hydrogels upon the introduction of oxidizing reagents. Here we introduce a strategy for stimuli responsive gel formation of mussel adhesive protein mimetic polymers. Lipid vesicles with a bilayer melting transition of 37°Cwere designed from a mixture of dipalmitoyl and dimyristoyl phosphatidylcholines and exploited for the release of a sequestered oxidizing reagent upon heating from ambient to physiologic temperature. Colorimetric studies indicated that sodium-periodate-loaded liposomes released their cargo at the phase transition temperature, and when used in conjunction with a DOPA-functionalized poly(ethylene glycol) polymer gave rise to rapid solidification of a crosslinked polymer hydrogel. The tissue adhesive properties of this biomimetic system were determined by in situ thermal gelation of liposome/polymer hydrogel between two porcine dermal tissue surfaces. Bond strength measurements showed that the bond formed by the adhesive hydrogel (mean = 35.1 kPa, SD = 12.5 kPa, n = 11) was several times stronger than a fibrin glue control tested under the same conditions. The results suggest a possible use of this biomimetic strategy for repair of soft tissues.

cells. We found that infection of cytokine-treated resting CD4؉ T cells in the presence of raltegravir or with integrase active-site mutant HIV-1 yielded de novo virus production following subsequent T cell activation. Infection with integration-competent HIV-1 naturally generated a population of cells generating virus from unintegrated DNA. Latent infection persisted for several weeks and could be activated to virus production by a combination of a histone deacetylase inhibitor and a protein kinase C activator or by T cell activation. HIV-1 Vpr was essential for unintegrated HIV-1 gene expression and de novo virus production in this system. Bypassing integration by this mechanism may allow the preservation of genetic information that otherwise would be lost.

BackgroundGaps in the HIV care continuum contribute to poor health outcomes and increase HIV transmission. A combination of interventions targeting multiple steps in the continuum is needed to achieve the full beneficial impact of HIV treatment.Methods and findingsLink4Health, a cluster-randomized controlled trial, evaluated the effectiveness of a combination intervention strategy (CIS) versus the standard of care (SOC) on the primary outcome of linkage to care within 1 month plus retention in care at 12 months after HIV-positive testing. Ten clusters of HIV clinics in Swaziland were randomized 1:1 to CIS versus SOC. The CIS included point-of-care CD4+ testing at the time of an HIV-positive test, accelerated antiretroviral therapy (ART) initiation for treatment-eligible participants, mobile phone appointment reminders, health educational packages, and noncash financial incentives. Secondary outcomes included each component of the primary outcome, mean time to linkage, assessment for ART eligibility, ART initiation and time to ART initiation, viral suppression defined as HIV-1 RNA < 1,000 copies/mL at 12 months after HIV testing among patients on ART ≥6 months, and loss to follow-up and death at 12 months after HIV testing. A total of 2,197 adults aged ≥18 years, newly tested HIV positive, were enrolled from 19 August 2013 to 21 November 2014 (1,096 CIS arm; 1,101 SOC arm) and followed for 12 months. The median participant age was 31 years (IQR 26–39), and 59% were women. In an intention-to-treat analysis, 64% (705/1,096) of participants at the CIS sites achieved the primary outcome versus 43% (477/1,101) at the SOC sites (adjusted relative risk [RR] 1.52, 95% CI 1.19–1.96, p = 0.002). Participants in the CIS arm versus the SOC arm had the following secondary outcomes: linkage to care regardless of retention at 12 months (RR 1.08, 95% CI 0.97–1.21, p = 0.13), mean time to linkage (2.5 days versus 7.5 days, p = 0.189), retention in care at 12 months regardless of time to linkage (RR 1.48, 95% CI 1.18–1.86, p = 0.002), assessment for ART eligibility (RR 1.20, 95% CI 1.07–1.34, p = 0.004), ART initiation (RR 1.16, 95% CI 0.96–1.40, p = 0.12), mean time to ART initiation from time of HIV testing (7 days versus 14 days, p < 0.001), viral suppression among those on ART for ≥6 months (RR 0.97, 95% CI 0.88–1.07, p = 0.55), loss to follow-up at 12 months after HIV testing (RR 0.56, 95% CI 0.40–0.79, p = 0.002), and death (N = 78) within 12 months of HIV testing (RR 0.80, 95% CI 0.46–1.35, p = 0.41). Limitations of this study include a small number of clusters and the inability to evaluate the incremental effectiveness of individual components of the combination strategy.ConclusionsA combination strategy inclusive of 5 evidence-based interventions aimed at multiple steps in the HIV care continuum was associated with significant increase in linkage to care plus 12-month retention. This strategy offers promise of enhanced outcomes for HIV-positive patients.Trial registrationClinicalTrials.gov NCT01904994.

HIF-1α is overexpressed in many human cancers compared to normal tissues due to the interaction of a multiplicity of factors and pathways that reflect specific genetic alterations and extracellular stimuli. We developed two HIF-1α chimeric reporter systems, HIF-1α/FLuc and HIF-1α(ΔODDD)/FLuc, to investigate the tightly controlled level of HIF-1α protein in normal (NIH3T3 and HEK293) and glioma (U87) cells. These reporter systems provided an opportunity to investigate the degradation of HIF-1α in different cell lines, both in culture and in xenografts. Using immunofluorescence microscopy, we observed different patterns of subcellular localization of HIF-1α/FLuc fusion protein between normal cells and cancer cells; similar differences were observed for HIF-1α in non-transduced, wild-type cells. A dynamic cytoplasmic-nuclear exchange of the fusion protein and HIF-1α was observed in NIH3T3 and HEK293 cells under different conditions (normoxia, CoCl2 treatment and hypoxia). In contrast, U87 cells showed a more persistent nuclear localization pattern that was less affected by different growing conditions. Employing a kinetic model for protein degradation, we were able to distinguish two components of HIF-1α/FLuc protein degradation and quantify the half-life of HIF-1α fusion proteins. The rapid clearance component (t1/2 ∼4–6 min) was abolished by the hypoxia-mimetic CoCl2, MG132 treatment and deletion of ODD domain, and reflects the oxygen/VHL-dependent degradation pathway. The slow clearance component (t1/2 ∼200 min) is consistent with other unidentified non-oxygen/VHL-dependent degradation pathways. Overall, the continuous bioluminescence readout of HIF-1α/FLuc stabilization in vitro and in vivo will facilitate the development and validation of therapeutics that affect the stability and accumulation of HIF-1α.