Impact of suboptimal APOBEC3G neutralization on the emergence of HIV drug resistance in humanized mice

HIV diversification facilitates immune escape and complicates antiretroviral therapy. In this study, we take advantage of a humanized mouse model to probe the contribution of APOBEC3 mutagenesis to viral evolution. Humanized mice were infected with isogenic HIV molecular clones (HIV-WT, HIV-45G, HIV-ΔSLQ) that differ in their ability to counteract APOBEC3G (A3G). Infected mice remained naïve or were treated with the RT inhibitor lamivudine (3TC). Viremia, emergence of drug resistant variants and quasispecies diversification in the plasma compartment were determined throughout infection. While both HIV-WT and HIV-45G achieved robust infection, over time HIV-45G replication was significantly reduced compared to HIV-WT in the absence of 3TC treatment. In contrast, treatment response differed significantly between HIV-45G and HIV-WT infected mice. Antiretroviral treatment failed in 91% of HIV-45G infected mice while only 36% of HIV-WT infected mice displayed a similar negative outcome. Emergence of 3TC resistant variants and nucleotide diversity were determined by analyzing 155,462 single HIV reverse transcriptase (RT) and 6,985 vif sequences from 33 mice. Prior to treatment, variants with genotypic 3TC resistance (RT-M184I/V) were detected at low levels in over a third of all animals. Upon treatment, the composition of the plasma quasispecies rapidly changed leading to a majority of circulating viral variants encoding RT-184I. Interestingly, increased viral diversity prior to treatment initiation correlated with higher plasma viremia in HIV-45G but not in HIV-WT infected animals. Taken together, HIV variants with suboptimal anti-A3G activity were attenuated in the absence of selection but display a fitness advantage in the presence of antiretroviral treatment.IMPORTANCE Both viral (e.g., reverse transcriptase, RT) and host factors (e.g., APOBEC3G (A3G)) can contribute to HIV sequence diversity. This study shows that suboptimal anti-A3G activity shapes viral fitness and drives viral evolution in the plasma compartment of humanized mice

Genome-to-genome analysis highlights the effect of the human innate and adaptive immune systems on the hepatitis C virus

Outcomes of hepatitis C virus (HCV) infection and treatment depend on viral and host genetic factors. Here we use human genome-wide genotyping arrays and new whole-genome HCV viral sequencing technologies to perform a systematic genome-to-genome study of 542 individuals who were chronically infected with HCV, predominantly genotype 3. We show that both alleles of genes encoding human leukocyte antigen molecules and genes encoding components of the interferon lambda innate immune system drive viral polymorphism. Additionally, we show that IFNL4 genotypes determine HCV viral load through a mechanism dependent on a specific amino acid residue in the HCV NS5A protein. These findings highlight the interplay between the innate immune system and the viral genome in HCV control

Targeted T1 Magnetic Resonance Imaging Contrast Enhancement with Extraordinarily Small CoFe2O4 Nanoparticles

Extraordinarily small (2.4 nm) cobalt ferrite nanoparticles (ESCIoNs) were synthesized by a one-pot thermal decomposition approach to study their potential as magnetic resonance imaging (MRI) contrast agents. Fine size control was achieved using oleylamine alone, and annular dark-field scanning transmission electron microscopy revealed highly crystalline cubic spinel particles with atomic resolution. Ligand exchange with dimercaptosuccinic acid rendered the particles stable in physiological conditions with a hydrodynamic diameter of 12 nm. The particles displayed superparamagnetic properties and a low r2/r1 ratio suitable for a T1 contrast agent. The particles were functionalized with bile acid, which improved biocompatibility by significant reduction of reactive oxygen species generation and is a first step toward liver-targeted T1 MRI. Our study demonstrates the potential of ESCIoNs as T1 MRI contrast agents

The first decade of oligotrophication of Lake Constance

In Lake Constance, after several decades of cutrophication, a decrease in phosphorus loading over the last decade has lead to a partial recovery from eutrophication. Here we analyse the shift in the taxonomic composition of phytoplankton during the first decade of oligotrophication in Lake Constance. During the 1980s, spring total P concentrations decreased from ca. 130 to less than 50 mgr·l–1. This decrease was reflected by an approximately proportional decrease in summer phytoplankton biomass while spring phytoplankton biomass seemed unresponsive. Major taxonomic changes occured during both growth seasons. In spring, the proportion of diatoms, green algae and Chrysophyta increased while the proportion of Cryptophyta decreased. The summer trend was very different: the relative importance of diatoms decreased and Cryptophyta and Chrysophyta increased, while Chlorophyta reached their peak around 1985. These trends are also analysed at the genus level. Comparison with taxonomic trends during the eutrophication period shows the expected reversals in most cases. Comparison with other lakes shows general similarities, with the notable exception that Planktothrix rubescens has never been important in Lake Constance. The increase of diatoms during spring is attributed to their improved competitive performance with increasing Si:P ratios. Their decrease during summer is explained by the increasing silicate removal from the epilimnion by increasing spring populations

Fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin with gemtuzumab ozogamicin improves event-free survival in younger patients with newly diagnosed aml and overall survival in patients with npm1 and flt3 mutations

Purpose To determine the optimal induction chemotherapy regimen for younger adults with newly diagnosed AML without known adverse risk cytogenetics. Patients and Methods One thousand thirty-three patients were randomly assigned to intensified (fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin [FLAG-Ida]) or standard (daunorubicin and Ara-C [DA]) induction chemotherapy, with one or two doses of gemtuzumab ozogamicin (GO). The primary end point was overall survival (OS). Results There was no difference in remission rate after two courses between FLAG-Ida + GO and DA + GO (complete remission [CR] + CR with incomplete hematologic recovery 93% v 91%) or in day 60 mortality (4.3% v 4.6%). There was no difference in OS (66% v 63%; P = .41); however, the risk of relapse was lower with FLAG-Ida + GO (24% v 41%; P < .001) and 3-year event-free survival was higher (57% v 45%; P < .001). In patients with an NPM1 mutation (30%), 3-year OS was significantly higher with FLAG-Ida + GO (82% v 64%; P = .005). NPM1 measurable residual disease (MRD) clearance was also greater, with 88% versus 77% becoming MRD-negative in peripheral blood after cycle 2 (P = .02). Three-year OS was also higher in patients with a FLT3 mutation (64% v 54%; P = .047). Fewer transplants were performed in patients receiving FLAG-Ida + GO (238 v 278; P = .02). There was no difference in outcome according to the number of GO doses, although NPM1 MRD clearance was higher with two doses in the DA arm. Patients with core binding factor AML treated with DA and one dose of GO had a 3-year OS of 96% with no survival benefit from FLAG-Ida + GO. Conclusion Overall, FLAG-Ida + GO significantly reduced relapse without improving OS. However, exploratory analyses show that patients with NPM1 and FLT3 mutations had substantial improvements in OS. By contrast, in patients with core binding factor AML, outcomes were excellent with DA + GO with no FLAG-Ida benefit

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Eye Care for Children in Special Schools: An Audit of Provision.

IntroductionChildren and young people with Special Educational Needs (SEN) are 28 times more likely to have eye problems than their typically developing peers. An ideal approach to the eye care for children attending special schools in England has been developed. Work in this area continues to evolve; therefore, an audit about existing services across the United Kingdom (UK) was undertaken.MethodA survey to ascertain key aspects of services for children with SEN that exist in the UK was developed and disseminated via Survey Monkey and at British and Irish Orthoptic Society (BIOS) events to all leads of the orthoptic profession.ResultsNinety-four service areas replied to the survey. Of these, 65 areas provide a special school service, 30 also provide a specialist service for SEN's in hospital/community clinics; five provide only a specialist service in hospital/community clinics, and 24 reported no specialist service provision, outside that provided to everyone. In the school environment, 29 (44%) areas include vision and orthoptic assessment, whereas 31 (48%) include vision, orthoptic, and refraction assessment. All but two services were reported as orthoptic-led, 26 (40%) special school services involved optometric input within school, and no services had optical dispensing within school.DiscussionThe results of this survey suggest that access to all aspects of eye care is not always available in school where a service exists. Families have to travel to the hospital or community optometrist for further assessment, which is not suitable in a number of cases, though it may be desirable, in some

Knowledge and attitudes to sexual health and STI testing for students at an Australian regional university: a cross-sectional study

Notifications for sexually transmitted diseases in young people in Australia are increasing. Young people are a priority population within the National Sexually Transmissible Infections Strategy, yet their knowledge of sexual health issues is limited. In the context of Health-Promoting Universities, we examined sexual health knowledge and access to care of both on and off-campus students at a regional university. In late 2012, 418 tertiary students aged 18-29 years completed an online baseline survey on their recent sexual behaviours and attitudes. In mid-2014, 956 students aged 18-31 years, of which 105 had completed the 2012 survey, completed the same or endline survey which also measured exposure to a university sexual health campaign. The low response rate to both the baseline and endline surveys meant only endline survey data were analysed. Two-thirds of students had been sexually active in the past 12 months. Students had positive attitudes towards condom use and STI screening. Around half reported using condoms at last sexual encounter. Students were positive about condom use, but hesitant about instigating it. STI screening was more prevalent than in the general Australian population, and largely accessed at General Practices. Screening was least likely in those with the greatest number of recent sexual partners and highest for those in de facto relationships. Students felt annual reminders or scheduled appointments would assist in ensuring STI screening. Findings showed regional university students are positive and knowledgeable about sexual health issues. Despite this, condom use is not consistent and more emphasis needs to be placed on STI transmission in this population. Students were willing to increase STI screening, and current initiatives to increase chlamydia screening in Australia are relevant to this population