11 research outputs found

    A robust assay to measure DNA topology-dependent protein binding affinity

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    © 2015 Published by Oxford University Press on behalf of Nucleic Acids Research 2014. DNA structure and topology pervasively influence aspects of DNA metabolism including replication, transcription and segregation. However, the effects of DNA topology on DNA-protein interactions have not been systematically explored due to limitations of standard affinity assays. We developed a method to measure protein binding affinity dependence on the topology (topological linking number) of supercoiled DNA. A defined range of DNA topoisomers at equilibrium with a DNA binding protein is separated into free and protein-bound DNA populations using standard nitrocellulose filter binding techniques. Electrophoretic separation and quantification of bound and free topoisomers combined with a simple normalization procedure provide the relative affinity of the protein for the DNA as a function of linking number. Employing this assay we measured topology-dependent DNA binding of a helicase, a type IB topoisomerase, a type IIA topoisomerase, a non-specific mitochondrial DNA binding protein and a type II restriction endonuclease. Most of the proteins preferentially bind negatively supercoiled DNA but the details of the topology-dependent affinity differ among proteins in ways that expose differences in their interactions with DNA. The topology-dependent binding assay provides a robust and easily implemented method to probe topological influences on DNA-protein interactions for a wide range of DNA binding proteins.Intramural Research Program of the National Heart, Lung, and Blood Institute of the National Institutes of Health; Medical Research Council of the United Kingdom. Cambridge International Scholarship Scheme from the University of Cambridge [to T.R.L.]. Funding for open access charge: Intramural Research Program of the National Heart, Lung, and Blood Institute of the National Institutes of HealthPeer Reviewe

    Somatic Host Cell Alterations in HPV Carcinogenesis

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    High-risk human papilloma virus (HPV) infections cause cancers in different organ sites, most commonly cervical and head and neck cancers. While carcinogenesis is initiated by two viral oncoproteins, E6 and E7, increasing evidence shows the importance of specific somatic events in host cells for malignant transformation. HPV-driven cancers share characteristic somatic changes, including apolipoprotein B mRNA editing catalytic polypeptide-like (APOBEC)-driven mutations and genomic instability leading to copy number variations and large chromosomal rearrangements. HPV-associated cancers have recurrent somatic mutations in phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) and phosphatase and tensin homolog (PTEN), human leukocyte antigen A and B (HLA-A and HLA-B)-A/B, and the transforming growth factor beta (TGFβ) pathway, and rarely have mutations in the tumor protein p53 (TP53) and RB transcriptional corepressor 1 (RB1) tumor suppressor genes. There are some variations by tumor site, such as NOTCH1 mutations which are primarily found in head and neck cancers. Understanding the somatic events following HPV infection and persistence can aid the development of early detection biomarkers, particularly when mutations in precancers are characterized. Somatic mutations may also influence prognosis and treatment decisions

    Recombinant GRA4 or ROP2 protein combined with alum or the gra4 gene provides partial protection in chronic murine models of toxoplasmosis

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    Fil: Martin, Valentina. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.Fil: Supanitsky, Alicia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.Fil: Echeverria, Pablo C. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.Fil: Litwin, Silvana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Tanos, Tamara. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.Fil: de Roodt, Adolfo R. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Guarnera, Eduardo. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.Fil: Angel, Sergio O. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.The efficacy of vaccination with Toxoplasma gondii recombinant GRA4 (rGRA4) and ROP2 (rRPO2) proteins and a mix of both combined with alum were evaluated in C57BL/6 and C3H mice. In C57BL/6 mice, rGRA4 and rGRA4-rROP2 immunizations generated similar levels of immunoglobulin G1 (IgG1) and IgG2a isotypes against GRA4, whereas immunizations with rROP2 and the mix induced a predominant IgG1 production against ROP2. All groups of C3H vaccinated mice exhibited higher levels of IgG1 than IgG2a. rGRA4-stimulated splenocytes from vaccinated mice produced primarily gamma interferon while those stimulated with rROP2 produced interleukin-4. Challenge of rGRA4- or rGRA4-rROP2-vaccinated mice from both strains with ME49 cysts resulted in fewer brain cysts than the controls, whereas vaccination with rROP2 alone only conferred protection to C3H mice. Immunization with a plasmid carrying the entire open reading frame of GRA4 showed a protective level similar to that of rGRA4 combined with alum. These results suggest that GRA4 can be a good candidate for a multiantigen anti-T. gondii vaccine based on the use of alum as an adjuvant

    Recombinant GRA4 or ROP2 protein combined with alum or the gra4 gene provides partial protection in chronic murine models of toxoplasmosis

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    Fil: Martin, Valentina. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.Fil: Supanitsky, Alicia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.Fil: Echeverria, Pablo C. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.Fil: Litwin, Silvana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Tanos, Tamara. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.Fil: de Roodt, Adolfo R. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Guarnera, Eduardo. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.Fil: Angel, Sergio O. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.The efficacy of vaccination with Toxoplasma gondii recombinant GRA4 (rGRA4) and ROP2 (rRPO2) proteins and a mix of both combined with alum were evaluated in C57BL/6 and C3H mice. In C57BL/6 mice, rGRA4 and rGRA4-rROP2 immunizations generated similar levels of immunoglobulin G1 (IgG1) and IgG2a isotypes against GRA4, whereas immunizations with rROP2 and the mix induced a predominant IgG1 production against ROP2. All groups of C3H vaccinated mice exhibited higher levels of IgG1 than IgG2a. rGRA4-stimulated splenocytes from vaccinated mice produced primarily gamma interferon while those stimulated with rROP2 produced interleukin-4. Challenge of rGRA4- or rGRA4-rROP2-vaccinated mice from both strains with ME49 cysts resulted in fewer brain cysts than the controls, whereas vaccination with rROP2 alone only conferred protection to C3H mice. Immunization with a plasmid carrying the entire open reading frame of GRA4 showed a protective level similar to that of rGRA4 combined with alum. These results suggest that GRA4 can be a good candidate for a multiantigen anti-T. gondii vaccine based on the use of alum as an adjuvant

    Recombinant GRA4 or ROP2 Protein Combined with Alum or the gra4 Gene Provides Partial Protection in Chronic Murine Models of Toxoplasmosis

    No full text
    The efficacy of vaccination with Toxoplasma gondii recombinant GRA4 (rGRA4) and ROP2 (rRPO2) proteins and a mix of both combined with alum were evaluated in C57BL/6 and C3H mice. In C57BL/6 mice, rGRA4 and rGRA4-rROP2 immunizations generated similar levels of immunoglobulin G1 (IgG1) and IgG2a isotypes against GRA4, whereas immunizations with rROP2 and the mix induced a predominant IgG1 production against ROP2. All groups of C3H vaccinated mice exhibited higher levels of IgG1 than IgG2a. rGRA4-stimulated splenocytes from vaccinated mice produced primarily gamma interferon while those stimulated with rROP2 produced interleukin-4. Challenge of rGRA4- or rGRA4-rROP2-vaccinated mice from both strains with ME49 cysts resulted in fewer brain cysts than the controls, whereas vaccination with rROP2 alone only conferred protection to C3H mice. Immunization with a plasmid carrying the entire open reading frame of GRA4 showed a protective level similar to that of rGRA4 combined with alum. These results suggest that GRA4 can be a good candidate for a multiantigen anti-T. gondii vaccine based on the use of alum as an adjuvant

    Design and Implementation of the All of Us Research Program COVID-19 Participant Experience (COPE) Survey

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    In response to the rapidly evolving COVID-19 pandemic, the All of Us Research Program longitudinal cohort study developed the COVID-19 Participant Experience (COPE) survey to better understand the pandemic experiences and health impacts of COVID-19 on diverse populations within the United States. Six survey versions were deployed between May 2020 and March 2021 covering mental health, loneliness, activity, substance use, and discrimination, as well as COVID-19 symptoms, testing, treatment, and vaccination. A total of 104,910 All of Us Research Program participants, of whom over 73% were from communities traditionally underrepresented in biomedical research, completed 275,201 surveys; 9,693 completed all six surveys. Response rates varied widely among demographic groups and were lower among participants from certain racial and ethnic minority populations, participants with low income or educational attainment, and participants with a Spanish language preference. Survey modifications improved participant response rates between the first and last surveys (13.9% to 16.1%, p \u3c 0.001). This paper describes a dataset with longitudinal COVID-19 survey data in a large, diverse population that will enable researchers to address important questions related to the pandemic, a dataset which is of additional scientific value when combined with the program\u27s other data sources

    Diminishing benefits of urban living for children and adolescents’ growth and development

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    Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified
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