32 research outputs found

    Insulin Degrading Enzyme Induces a Conformational Change in Varicella-Zoster Virus gE, and Enhances Virus Infectivity and Stability

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    Varicella-zoster virus (VZV) glycoprotein E (gE) is essential for virus infectivity and binds to a cellular receptor, insulin-degrading enzyme (IDE), through its unique amino terminal extracellular domain. Previous work has shown IDE plays an important role in VZV infection and virus cell-to-cell spread, which is the sole route for VZV spread in vitro. Here we report that a recombinant soluble IDE (rIDE) enhances VZV infectivity at an early step of infection associated with an increase in virus internalization, and increases cell-to-cell spread. VZV mutants lacking the IDE binding domain of gE were impaired for syncytia formation and membrane fusion. Pre-treatment of cell-free VZV with rIDE markedly enhanced the stability of the virus over a range of conditions. rIDE interacted with gE to elicit a conformational change in gE and rendered it more susceptible to proteolysis. Co-incubation of rIDE with gE modified the size of gE. We propose that the conformational change in gE elicited by IDE enhances infectivity and stability of the virus and leads to increased fusogenicity during VZV infection. The ability of rIDE to enhance infectivity of cell-free VZV over a wide range of incubation times and temperatures suggests that rIDE may be useful for increasing the stability of varicella or zoster vaccines

    Mycobacterium tuberculosis epitope-specific interferon-g production in healthy Brazilians reactive and non-reactive to tuberculin skin test

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    The interferon (IFN)-gamma response to peptides can be a useful diagnostic marker of Mycobacterium tuberculosis (MTB) latent infection. We identified promiscuous and potentially protective CD4(+) T-cell epitopes from the most conserved regions of MTB antigenic proteins by scanning the MTB antigenic proteins GroEL2, phosphate-binding protein 1 precursor and 19 kDa antigen with the TEPITOPE algorithm. Seven peptide sequences predicted to bind to multiple human leukocyte antigen (HLA)-DR molecules were synthesised and tested with IFN-gamma enzyme-linked immunospot (ELISPOT) assays using peripheral blood mononuclear cells (PBMCs) from 16 Mantoux tuberculin skin test (TST)-positive and 16 TST-negative healthy donors. Eighty-eight percent of TST-positive donors responded to at least one of the peptides, compared to 25% of TST-negative donors. Each individual peptide induced IFN-gamma production by PBMCs from at least 31% of the TST-positive donors. the magnitude of the response against all peptides was 182 +/- 230 x 10(6) IFN-gamma spot forming cells (SFC) among TST-positive donors and 36 +/- 62 x 10(6) SFC among TST-negative donors (p = 0.007). the response to GroEL2 (463-477) was only observed in the TST-positive group. This combination of novel MTB CD4 T-cell epitopes should be tested in a larger cohort of individuals with latent tuberculosis (TB) to evaluate its potential to diagnose latent TB and it may be included in ELISPOT-based IFN-gamma assays to identify individuals with this condition.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Fac Med, Inst Coracao, Immunol Lab, São Paulo, BrazilUniversidade Federal de São Paulo, Fac Med, Dept Med, Div Imunol Clin & Alergia, São Paulo, BrazilFundacao Oswaldo Cruz, Lab Avancado Saude Publ, Salvador, BA, BrazilEscola Bahiana Med & Saude Publ, Salvador, BA, BrazilInst Invest Immunol, São Paulo, BrazilUniversidade Federal de São Paulo, Fac Med, Inst Coracao, Immunol Lab, São Paulo, BrazilUniversidade Federal de São Paulo, Fac Med, Dept Med, Div Imunol Clin & Alergia, São Paulo, BrazilWeb of Scienc

    Understanding sleep facilitators, barriers, and cultural dimensions in Native American urban youth.

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    OBJECTIVES: American Indian/Alaska Native (AI/AN) youth are a high-risk group for sleep problems and associated chronic conditions. Urban AI/AN youth may face certain challenges, including specific psychosocial stressors (e.g., discrimination) and environmental factors (e.g., noise, light) that render them particularly vulnerable to poor sleep health. However, few studies have explored AI/AN adolescent sleep. To our knowledge, this is the first study to use systematic qualitative methods with AI/AN youth to explore their sleep environment and sleep behaviors. DESIGN: In-depth interviews with 26 youth. SETTING: Two urban areas in Central and Southern California. PARTICIPANTS: Urban-dwelling AI/AN youth, age 12-16 years. INTERVENTION: N/A. MEASUREMENT: N/A. RESULTS: We identified five main themes, each with subthemes: sleep patterns and desired sleep, sleep barriers inside the home, environmental factors, sleep facilitators, and cultural dimensions. Key concerns discussed were poor sleep hygiene, excessive use of electronics prior to bedtime, issues with temperature regulation, and noise both within and outside the home. Parents can be an important vehicle for messaging around sleep health and for behavior management. Participating adolescents also indicated differing levels of attachment to Native identity, suggesting that culturally-targeted sleep interventions should build in openness and flexibility to a range of identity starting points. Further, we identified cultural practices, such as sweat lodges and dreamcatchers, that could be incorporated in future sleep interventions for this population. CONCLUSION: Findings increase our understanding of urban AI/AN youths sleep environments and behaviors, thus potentially informing program development around sleep health for this vulnerable population

    Unveiling an invisible population: health, substance use, sexual behavior, culture, and discrimination among urban American Indian/Alaska Native adolescents in California.

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    Objectives: There are limited public health data on urban American Indian/Alaska Native (AI/AN) populations, particularly adolescents. The current study attempted to address gaps by providing descriptive information on experiences of urban AI/AN adolescents across northern, central, and southern California.Design: We describe demographics and several behavioral health and cultural domains, including: alcohol and other drug (AOD) use, risky sexual behavior, mental and physical health, discrimination experiences, involvement in traditional practices, and cultural pride and belonging. We recruited 185 urban AI/AN adolescents across northern, central, and southern California from 2014 to 2017 who completed a baseline survey as part of a randomized controlled intervention trial.Results: Average age was 15.6 years; 51% female; 59% of adolescents that indicated AI/AN descent also endorsed another race or ethnicity. Rates of AOD use in this urban AI/AN sample were similar to rates for Monitoring the Future. About one-third of adolescents reported ever having sexual intercourse, with 15% reporting using alcohol or drugs before sex. Most reported good mental and physical health. Most urban AI/AN adolescents participated in traditional practices, such as attending Pow Wows and learning their tribal history. Adolescents also reported discrimination experiences, including being a victim of racial slurs and discrimination by law enforcement.Conclusions: This study describes a select sample of California urban AI/AN adolescents across several behavioral health and cultural domains. Although these adolescents reported numerous discrimination experiences and other stressors, findings suggest that this sample of urban AI/AN teens may be particularly resilient with regard to behavioral health

    Mental Health, Physical Health, and Cultural Characteristics Among American Indians/Alaska Natives Seeking Substance Use Treatment in an Urban Setting: A Descriptive Study.

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    Although approximately 70% of American Indians/Alaska Natives (AI/ANs) reside in urban areas, our knowledge of risk and protective factors among AI/ANs seeking substance use treatment within urban areas is limited. We analyze substance and commercialized cigarette use, AI/AN cultural identity and involvement, physical health and cognitive functioning, and mental health symptoms among 63 AI/AN adults seeking substance use treatment within an urban area in California. Alcohol (37%), marijuana (27%), and methamphetamine (22%) were the most commonly reported substances. Sixty-two percent used commercialized tobacco use. The majority of AI/AN adults (78%) engaged in at least one traditional practice during the past month and endorsed high levels of spiritual connectedness. Those who engaged in traditional practices demonstrated significantly less depression (p = 0.007) and anxiety (p = 0.04). Medical and mental health issues were not prominent, although participants revealed high levels of cognitive impairment. Results highlight the importance of utilizing AI/AN traditional practices for AI/AN adults seeking substance use treatment within urban areas. Clinical Trials Registry Number NCT01356667
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