Is HIV-1 RNA dimerization a prerequisite for packaging? Yes, no, probably?

During virus assembly, all retroviruses specifically encapsidate two copies of full-length viral genomic RNA in the form of a non-covalently linked RNA dimer. The absolute conservation of this unique genome structure within the Retroviridae family is strong evidence that a dimerized genome is of critical importance to the viral life cycle. An obvious hypothesis is that retroviruses have evolved to preferentially package two copies of genomic RNA, and that dimerization ensures the proper packaging specificity for such a genome. However, this implies that dimerization must be a prerequisite for genome encapsidation, a notion that has been debated for many years. In this article, we review retroviral RNA dimerization and packaging, highlighting the research that has attempted to dissect the intricate relationship between these two processes in the context of HIV-1, and discuss the therapeutic potential of these putative antiretroviral targets

Natural Killer Cell Function and Dysfunction in Hepatitis C Virus Infection

Viruses must continually adapt against dynamic innate and adaptive responses of the host immune system to establish chronic infection. Only a small minority (∼20%) of those exposed to hepatitis C virus (HCV) spontaneously clear infection, leaving approximately 200 million people worldwide chronically infected with HCV. A number of recent research studies suggest that establishment andmaintenance of chronicHCVinfection involve natural killer (NK) cell dysfunction. This relationship is illustrated in vitro by disruption of typicalNK cell responses including both cell-mediated cytotoxicity and cytokine production. Expression of a number of activating NK cell receptors in vivo is also affected in chronic HCV infection.Thus, direct in vivo and in vitro evidence of compromised NK function in chronic HCV infection in conjunction with significant epidemiological associations between the outcome of HCV infection and certain combinations of NK cell regulatory receptor and class I human histocompatibility linked antigen (HLA) genotypes indicate that NK cells are important in the immune response against HCV infection. In this review, we highlight evidence suggesting that selective impairment of NK cell activity is related to establishment of chronic HCV infection

Prediction, dynamics, and visualization of antigenic phenotypes of seasonal influenza viruses

Human seasonal influenza viruses evolve rapidly, enabling the virus population to evade immunity and reinfect previously infected individuals. Antigenic properties are largely determined by the surface glycoprotein hemagglutinin (HA), and amino acid substitutions at exposed epitope sites in HA mediate loss of recognition by antibodies. Here, we show that antigenic differences measured through serological assay data are well described by a sum of antigenic changes along the path connecting viruses in a phylogenetic tree. This mapping onto the tree allows prediction of antigenicity from HA sequence data alone. The mapping can further be used to make predictions about the makeup of the future A(H3N2) seasonal influenza virus population, and we compare predictions between models with serological and sequence data. To make timely model output readily available, we developed a web browser-based application that visualizes antigenic data on a continuously updated phylogeny

ACE-ASIA - Regional climatic and atmospheric chemical effects of Asian dust and pollution

Although continental-scale plumes of Asian dust and pollution reduce the amount of solar radiation reaching the earth's surface and perturb the chemistry of the atmosphere, our ability to quantify these effects has been limited by a lack of critical observations, particularly of layers above the surface. Comprehensive surface, airborne, shipboard, and satellite measurements of Asian aerosol chemical composition, size, optical properties, and radiative impacts were performed during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) study. Measurements within a massive Chinese dust storm at numerous widely spaced sampling locations revealed the highly complex structure of the atmosphere, in which layers of dust, urban pollution, and biomass-burning smoke may be transported long distances as distinct entities or mixed together. The data allow a first-time assessment of the regional climatic and atmospheric chemical effects of a continental-scale mixture of dust and pollution. Our results show that radiative flux reductions during such episodes are sufficient to cause regional climate change

HIV non-B subtype distribution: emerging trends and risk factors for imported and local infections newly diagnosed in South Australia

Monitoring HIV subtype distribution is important for understanding transmission dynamics. Subtype B has historically been dominant in Australia, but in recent years new clades have appeared. Since 2000, clade data have been collected as part of HIV surveillance in South Australia. The aim of this study was to evaluate the prevalence of and risk factors for HIV-1 non-B subtypes. The study population was composed of newly diagnosed, genotyped HIV subjects in South Australia between 2000 and 2010. We analyzed time trends and subtype patterns in this cohort; notification data were aggregated into three time periods (2000–2003, 2004–2006, and 2007–2010). Main outcome measures were number of new non-B infections by year, exposure route, and other demographic characteristics. There were 513 new HIV diagnoses; 425 had information on subtype. The majority (262/425) were in men who have sex with men (MSM), predominantly subtype B and acquired in Australia. Infections acquired in Australia decreased from 77% (2000–2003) to 64% (2007–2010) ( p = 0.007) and correspondingly the proportion of subtype B declined from 85% to 68% ( p = 0.002). Non-B infections were predominantly (83%) heterosexual contacts, mostly acquired overseas (74%). The majority (68%) of non-B patients were born outside of Australia. There was a non-significant increase from 1.6% to 4.2% in the proportion of locally transmitted non-B cases (p = 0.3). Three non-B subtypes and two circulating recombinant forms (CRFs) were identified: CRF_AE (n = 41), C (n = 36), CRF_AG (n = 13), A (n = 9), and D (n = 2). There has been a substantial increase over the past decade in diagnosed non-B infections, primarily through cases acquired overseas

1998 CSREES Wild Blueberry Project Results

The 1998 edition of the CSREES Wild Blueberry Project Results was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include: 1. Separation of Maggot Infested Blueberries in the IQF Processing Line 2. Assessment of Preharvest Treatments on Wild blueberry Fruit Quality 3. Blueberries as a Natural Colorant for Breakfast Cereals 4. Factors Affecting Quality of IQF Wild Blueberries 5. Control Tactics for Wild blueberry Pest Insects 6. Biology and Ecology of Wild blueberry Pest Insects 7. Sustainable Pollination of Wild blueberry 8. Evaluation of Foliar Fungicides for Control of Mummy Berry 9. Phosphorus/Nitrogen Fertilizer Ratio 10. Effect of Boron Application Methods on Boron Uptake in Wild Blueberries 11. Effect of Zinc Application on Growth and Yield of Wild Blueberries 12. Effect of Soil pH of Nutrient Uptake 13. Crop Year Fertilization of Wild blueberry 14. Effect of Fertilizer Timing on Wild blueberry Growth and Productivity 15. Alternative Methods of Grass Control 16. Cultural Weed Management Using pH 17. Investigation of Hexazinone Alternatives for Weed Control 18. Evaluation of Hexazinone Applications in the Cropping Year 19. Effect of Surfactant and Ammonium Sulfate on Glyphosate Activity 20. Evaluation of Pronone MG® Spot Treatments for Control of St Jobnswort, Dogbane, Bracken Fem, Witch Grass/Fall Panicum and Bunchberry 21. Hexazinone Groundwater Surve

Wild Blueberries 1999 CSREES Progress Reports

The 1999 edition of the Wild Blueberries CSREES Progress Reports was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include: 1. Effects of QF Processing on Microbiological Quality of Maine Wild Blueberries 2. Separation of Maggot-Infested Blueberries in the IQF Processing Line 3. Determination of Pesticide Residue Levels in Fresh and Processed Wild Blueberries 4. Control Tactics for Blueberry Pest Insects 5. IPM Strategies 6. Biology and Ecology of Blueberry Pest Insects 7. Survey of Stem Blight and Leaf Spot Diseases in Lowbush Blueberry Fields 8. Phosphorus/Nitrogen Fertilizer Ratio 9. Effect of Fertilizer Timing on Lowbush Blueberry Growth and Productivity 10. Effect of Soil pH on Nutrient Uptake 11. Effect of Boron Application Methods on Boron Uptake in Lowbush Blueberries 12. Effect of Nutri-Phite P+K on growth and yield of lowbush blueberry 13. Effect of Crop-Set on growth and yield of lowbush blueberry 14. Crop year fertilization of lowbush blueberry 15. Alternative Methods of Grass Control 16. Cultural Weed Management Using pH 17. Investigation of Hexazinone Alternatives for Weed Control 18. Comparison of Sulfosate and Glyphosate for Weed Control 19. Evaluation of VC1447 for Weed Control in Wild blueberries 20. Blueberry/ Cranberry Extension Education Program in 1999 21. Effect of Rate, Formulation and Application Method on Efficacy and Phytotoxicity of Granular Hexazinone in Wild Blueberry Fields 22. 1999 Fungicide Evaluation Field Trial 23. 1999 Hexazinone Groundwater Survey Pollination 24. Sustainable Pollination of Wild Blueberr