Identification of two distinct structural regions in a human porcine endogenous retrovirus receptor, HuPAR2, contributing to function for viral entry

<p>Abstract</p> <p>Background</p> <p>Of the three subclasses of Porcine Endogenous Retrovirus (PERV), PERV-A is able to infect human cells via one of two receptors, HuPAR1 or HuPAR2. Characterizing the structure-function relationships of the two HuPAR receptors in PERV-A binding and entry is important in understanding receptor-mediated gammaretroviral entry and contributes to evaluating the risk of zoonosis in xenotransplantation.</p> <p>Results</p> <p>Chimeras of the non-permissive murine PAR and the permissive HuPAR2, which scanned the entire molecule, revealed that the first 135 amino acids of HuPAR2 are critical for PERV-A entry. Within this critical region, eighteen single residue differences exist. Site-directed mutagenesis used to map single residues confirmed the previously identified L109 as a binding and infectivity determinant. In addition, we identified seven residues contributing to the efficiency of PERV-A entry without affecting envelope binding, located in multiple predicted structural motifs (intracellular, extracellular and transmembrane). We also show that expression of HuPAR2 in a non-permissive cell line results in an average 11-fold higher infectivity titer for PERV-A compared to equal expression of HuPAR1, although PERV-A envelope binding is similar. Chimeras between HuPAR-1 and -2 revealed that the region spanning amino acids 152–285 is responsible for the increase of HuPAR2. Fine mapping of this region revealed that the increased receptor function required the full sequence rather than one or more specific residues.</p> <p>Conclusion</p> <p>HuPAR2 has two distinct structural regions. In one region, a single residue determines binding; however, in both regions, multiple residues influence receptor function for PERV-A entry.</p

The Diversity and Inclusivity Survey: Final Report

In 2018 Academic Placement Data and Analysis ran a survey of doctoral students and recent graduates on the topics of diversity and inclusivity in collaboration with the Graduate Student Council and Data Task Force of the American Philosophical Association. We submitted a preliminary report in Fall 2018 that describes the origins and procedure of the survey [1]. This is our final report on the survey. We first discuss the demographic profile of our survey participants and compare it to the United States general population, its doctoral students, and APA membership, finding several areas of underrepresentation (i.e. gender, race/ethnicity, socioeconomic, and veteran status). We then discuss the results of questions regarding diversity and inclusivity. We find, for instance, that participant comfort in philosophy depends on gender, sexuality, race/ethnicity, disability, and language status and that participants most often mentioned the theme of diversity when asked how philosophy could be more inclusive. Finally, we discuss the results of questions related to graduate program and placement. We find, for example, that underrepresented graduates are both less likely to recommend their graduate program to others and less likely to prefer an academic job. We close by making some recommendations for the APA and for the discipline based on our findings

A new, practicable and economical cage design for experimental studies on small honey bee colonies

Bees are in decline globally as a result of multiple stressors including pests, pathogens and contaminants. The management of bees in enclosures can identify causes of decline under standardized conditions but the logistics of conducting effect studies in typical systems used across several colonies is complex and costly. This study details a practicable, new and economical cage system that effectively houses live honey bee colonies to investigate the impact of physical conditions, biological factors and environmental contaminants on honey bee health. The method has broad application for a range of effect studies concerning honey bee development, physiology, survival and population dynamics because it enables entire colonies, as opposed to individual workers, to be managed well in captivity

Induction of ebolavirus cross-species immunity using retrovirus-like particles bearing the Ebola virus glycoprotein lacking the mucin-like domain

<p>Abstract</p> <p>Background</p> <p>The genus <it>Ebolavirus </it>includes five distinct viruses. Four of these viruses cause hemorrhagic fever in humans. Currently there are no licensed vaccines for any of them; however, several vaccines are under development. Ebola virus envelope glycoprotein (GP_1,2) is highly immunogenic, but antibodies frequently arise against its least conserved mucin-like domain (MLD). We hypothesized that immunization with MLD-deleted GP_1,2(GPΔMLD) would induce cross-species immunity by making more conserved regions accessible to the immune system.</p> <p>Methods</p> <p>To test this hypothesis, mice were immunized with retrovirus-like particles (retroVLPs) bearing Ebola virus GPΔMLD, DNA plasmids (plasmo-retroVLP) that can produce such retroVLPs <it>in vivo</it>, or plasmo-retroVLP followed by retroVLPs.</p> <p>Results</p> <p>Cross-species neutralizing antibody and GP_1,2-specific cellular immune responses were successfully induced.</p> <p>Conclusion</p> <p>Our findings suggest that GPΔMLD presented through retroVLPs may provide a strategy for development of a vaccine against multiple ebolaviruses. Similar vaccination strategies may be adopted for other viruses whose envelope proteins contain highly variable regions that may mask more conserved domains from the immune system.</p

Methylated DNA Immunoprecipitation

The identification of DNA methylation patterns is a common procedure in the study of epigenetics, as methylation is known to have significant effects on gene expression, and is involved with normal development as well as disease 1-4. Thus, the ability to discriminate between methylated DNA and non-methylated DNA is essential for generating methylation profiles for such studies. Methylated DNA immunoprecipitation (MeDIP) is an efficient technique for the extraction of methylated DNA from a sample of interest 5-7. A sample of as little as 200 ng of DNA is sufficient for the antibody, or immunoprecipitation (IP), reaction. DNA is sonicated into fragments ranging in size from 300-1000 bp, and is divided into immunoprecipitated (IP) and input (IN) portions. IP DNA is subsequently heat denatured and then incubated with anti-5'mC, allowing the monoclonal antibody to bind methylated DNA. After this, magnetic beads containing a secondary antibody with affinity for the primary antibody are added, and incubated. These bead-linked antibodies will bind the monoclonal antibody used in the first step. DNA bound to the antibody complex (methylated DNA) is separated from the rest of the DNA by using a magnet to pull the complexes out of solution. Several washes using IP buffer are then performed to remove the unbound, non-methylated DNA. The methylated DNA/antibody complexes are then digested with Proteinase K to digest the antibodies leaving only the methylated DNA intact. The enriched DNA is purified by phenol:chloroform extraction to remove the protein matter and then precipitated and resuspended in water for later use. PCR techniques can be used to validate the efficiency of the MeDIP procedure by analyzing the amplification products of IP and IN DNA for regions known to lack and known to contain methylated sequences. The purified methylated DNA can then be used for locus-specific (PCR) or genome-wide (microarray and sequencing) methylation studies, and is particularly useful when applied in conjunction with other research tools such as gene expression profiling and array comparative genome hybridization (CGH) 8. Further investigation into DNA methylation will lead to the discovery of new epigenetic targets, which in turn, may be useful in developing new therapeutic or prognostic research tools for diseases such as cancer that are characterized by aberrantly methylated DNA 2, 4, 9-11

Obese endometrial cancer survivors\u27 perceptions of weight loss strategies and characteristics that may influence participation in behavioral interventions

We aimed to evaluate obese endometrial cancer (EC) survivors\u27 perceptions of weight loss barriers and previously attempted weight loss methods and to identify characteristics that predicted willingness to enroll in a behavioral intervention trial. We administered a 27-question baseline survey at an academic institution to EC survivors with body mass index ≥ 30 kg/