36 research outputs found

    Extracting Food Substitutes From Food Diary via Distributional Similarity

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    Genetic ancestry admixture of patients infected with Influenza A(H1N1)pdm09 sorted by African ancestry. Each individual ancestry is depicted as a column, whereas color represents the proportion of ancestry estimated for that individual (African = blue; European = brown; Native American = green). (A) Non-hospitalized patients and (B) Hospitalized patients

    Prior Dengue Virus Exposure Shapes T Cell Immunity to Zika Virus in Humans

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    While progress has been made in characterizing humoral immunity to Zika virus (ZIKV) in humans, little is known regarding the corresponding T cell responses to ZIKV. Here, we investigate the kinetics and viral epitopes targeted by T cells responding to ZIKV and address the critical question of whether preexisting dengue virus (DENV) T cell immunity modulates these responses. We find that memory T cell responses elicited by prior infection with DENV or vaccination with tetravalent dengue attenuated vaccines (TDLAV) recognize ZIKV-derived peptides. This cross-reactivity is explained by the sequence similarity of the two viruses, as the ZIKV peptides recognized by DENV-elicited memory T cells are identical or highly conserved in DENV and ZIKV. DENV exposure prior to ZIKV infection also influences the timing and magnitude of the T cell response. ZIKV-reactive T cells in the acute phase of infection are detected earlier and in greater magnitude in DENV-immune patients. Conversely, the frequency of ZIKV-reactive T cells continues to rise in the convalescent phase in DENV-naive donors but declines in DENV-preexposed donors, compatible with more efficient control of ZIKV replication and/or clearance of ZIKV antigen. The quality of responses is also influenced by previous DENV exposure, and ZIKV-specific CD8 T cells from DENV-preexposed donors selectively upregulated granzyme B and PD1, unlike DENV-naive donors. Finally, we discovered that ZIKV structural proteins (E, prM, and C) are major targets of both the CD4 and CD8 T cell responses, whereas DENV T cell epitopes are found primarily in nonstructural proteins. IMPORTANCE The issue of potential ZIKV and DENV cross-reactivity and how preexisting DENV T cell immunity modulates Zika T cell responses is of great relevance, as the two viruses often cocirculate and Zika virus has been spreading in geographical regions where DENV is endemic or hyperendemic. Our data show that memory T cell responses elicited by prior infection with DENV recognize ZIKV-derived peptides and that DENV exposure prior to ZIKV infection influences the timing, magnitude, and quality of the T cell response. Additionally, we show that ZIKV-specific responses target different proteins than DENV-specific responses, pointing toward important implications for vaccine design against this global threat

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    Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Universidade Federal do Pará. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil

    Neurological manifestations in people living with HIV/AIDS in the late cART era: a prospective observational study at a tertiary healthcare center in SĂŁo Paulo, Brazil

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    Background:The aim of this study was to evaluate the frequency, spectrum, in-hospital mortality rate, and factors associated with death in people living with HIV/AIDS (PLWHA) presenting with neurological diseases from a middle-income country, as well as estimate its one-year global death rate. Methods:This prospective observational cohort study was conducted at a Brazilian tertiary health center between January and July 2017. HIV-infected patients above 18 years of age who were admitted due to neurological complaints were consecutively included. A standardized neurological examination and patient and/or medical assistant interviews were performed weekly until the patient’s discharge or death. The diagnostic and therapeutic management of the included cases followed institutional routines. Results:A total of 105 (13.2%) patients were included among the 791 hospitalized PLWHA. The median age was 42.8 [34-51] years, and 61% were men. The median CD4+ lymphocyte cell count was 70 (27-160) cells/mm3, and 90% of patients were experienced in combined antiretroviral therapy. The main diseases were cerebral toxoplasmosis (36%), cryptococcal meningitis (14%), and tuberculous meningitis (8%). Cytomegalovirus causing encephalitis, polyradiculopathy, and/or retinitis was the third most frequent pathogen (12%). Moreover, concomitant neurological infections occurred in 14% of the patients, and immune reconstitution inflammatory syndrome-related diseases occurred in 6% of them. In-hospital mortality rate was 12%, and multivariate analysis showed that altered level of consciousness (P = 0.04; OR: 22.7, CI 95%: 2.6-195.1) and intensive care unit (ICU) admission (P = 0.014; OR: 6.2, CI 95%: 1.4-26.7) were associated with death. The one-year global mortality rate was 31%. Conclusion:In this study, opportunistic neurological diseases were predominant. Cytomegalovirus was a frequent etiological agent, and neurological concomitant diseases were common. ICU admission and altered levels of consciousness were associated with death. Although in-hospital mortality was relatively low, the one-year global death rate was higher

    The His131Arg substitution in the FCGR2A gene (rs1801274) is not associated with the severity of influenza A(H1N1) pdm09 infection

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    Universidade Federal do Pará. Laboratório de Genética Humana e Médica. Belém, PA, Brasil.Universidade Federal do Pará. Núcleo de Pesquisas em Oncologia. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Vírus Respiratórios. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Vírus Respiratórios. Ananindeua, PA, Brasil.Universidade Federal do Pará. Laboratório de Genética Humana e Médica. Belém, Pará, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Vírus Respiratórios. Ananindeua, PA, Brasil.Universidade Federal do Pará. Núcleo de Pesquisas em Oncologia. Belém, PA, Brasil / Universidade Federal do Pará. Laboratório de Genética Humana e Médica. Belém, Pará, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brazil / Universidade Federal do Pará. Belém, PA, Brasil.Background: The virulence and pathogenicity of different influenza strains are responsible for a more or less severe disease. Recent studies have attempted to understand how host genetic factors may influence the clinical presentation of the disease. In the present study, the His131Arg (rs1801274) polymorphism was investigated in individuals from a Brazilian admixed population with a diagnosis of influenza A(H1N1)pdm09 infection. Methods: In the present study, the influence of the His131Arg (rs1801274) polymorphism, a variant of the FCGR2A gene, was investigated in 436 patients with a diagnosis of influenza A(H1N1)pdm09, evaluated at health services in the northern and northeastern regions of Brazil between June 2009 and August 2010. Patients were divided into a group of non-hospitalized patients (n = 192) and a group of hospitalized patients (n = 244; 100 of them died). Results: No significant difference in the allele or genotype frequencies of the rs1801274 polymorphism was observed between groups (p = 0.952 and p = 0.388). Multinomial logistic regression showed no effect of the rs1801274 polymorphism on severity or death of patients from the Brazilian admixed population (p = 0.368 and p = 0.469). Conclusions: The rs1801274 polymorphism is not associated with severe disease in patients infected with influenza A(H1N1)pdm09

    Persistence of Rabies Virus-Neutralizing Antibodies after Vaccination of Rural Population following Vampire Bat Rabies Outbreak in Brazil

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    International audienceBackground: Animal control measures in Latin America have decreased the incidence of urban human rabies transmitted by dogs and cats; currently most cases of human rabies are transmitted by bats. In 2004-2005, rabies outbreaks in populations living in rural Brazil prompted widespread vaccination of exposed and at-risk populations. More than 3,500 inhabitants of Augusto Correa (Pará State) received either post-exposure (PEP) or pre-exposure (PrEP) prophylaxis. This study evaluated the persistence of rabies virus-neutralizing antibodies (RVNA) annually for 4 years post-vaccination. The aim was to evaluate the impact of rabies PrEP and PEP in a population at risk living in a rural setting to help improve management of vampire bat exposure and provide additional data on the need for booster vaccination against rabies.Methodology/principal findings: This prospective study was conducted in 2007 through 2009 in a population previously vaccinated in 2005; study participants were followed-up annually. An RVNA titer >0.5 International Units (IU)/mL was chosen as the threshold of seroconversion. Participants with titers ≤0.5 IU/mL or Equivalent Units (EU)/mL at enrollment or at subsequent annual visits received booster doses of purified Vero cell rabies vaccine (PVRV). Adherence of the participants from this Amazonian community to the study protocol was excellent, with 428 of the 509 (84%) who attended the first interview in 2007 returning for the final visit in 2009. The long-term RVNA persistence was good, with 85-88.0% of the non-boosted participants evaluated at each yearly follow-up visit remaining seroconverted. Similar RVNA persistence profiles were observed in participants originally given PEP or PrEP in 2005, and the GMT of the study population remained >1 IU/mL 4 years after vaccination. At the end of the study, 51 subjects (11.9% of the interviewed population) had received at least one dose of booster since their vaccination in 2005.Conclusions/significance: This study and the events preceding it underscore the need for the health authorities in rabies enzootic countries to decide on the best strategies and timing for the introduction of routine rabies PrEP vaccination in affected areas

    Robust and Functional Immune Memory Up to 9 Months After SARS-CoV-2 Infection: A Southeast Asian Longitudinal Cohort

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    International audienceThe duration of humoral and cellular immune memory following SARS-CoV-2 infection in populations in least developed countries remains understudied but is key to overcome the current SARS-CoV-2 pandemic. Sixty-four Cambodian individuals with laboratory-confirmed infection with asymptomatic or mild/moderate clinical presentation were evaluated for Spike (S)-binding and neutralizing antibodies and antibody effector functions during acute phase of infection and at 6-9 months follow-up. Antigen-specific B cells, CD4 + and CD8 + T cells were characterized, and T cells were interrogated for functionality at late convalescence. Anti-S antibody titers decreased over time, but effector functions mediated by S-specific antibodies remained stable. S- and nucleocapsid (N)-specific B cells could be detected in late convalescence in the activated memory B cell compartment and are mostly IgG + . CD4 + and CD8 + T cell immune memory was maintained to S and membrane (M) protein. Asymptomatic infection resulted in decreased antibody-dependent cellular cytotoxicity (ADCC) and frequency of SARS-CoV-2-specific CD4 + T cells at late convalescence. Whereas anti-S antibodies correlated with S-specific B cells, there was no correlation between T cell response and humoral immune memory. Hence, all aspects of a protective immune response are maintained up to nine months after SARS-CoV-2 infection and in the absence of re-infection

    Siaα2-3Galβ1- Receptor Genetic Variants Are Associated with <i>Influenza A(H1N1)pdm09</i> Severity

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    <div><p>Different host genetic variants may be related to the virulence and transmissibility of pandemic <i>Influenza A(H1N1)pdm09</i>, influencing events such as binding of the virus to the entry receptor on the cell of infected individuals and the host immune response. In the present study, two genetic variants of the <i>ST3GAL1</i> gene, which encodes the Siaα2-3Galβ1- receptor to which <i>influenza A(H1N1)pdm09 virus</i> binds for entry into the host cell, were investigated in an admixed Brazilian population. First, the six exons encoding the <i>ST3GAL1</i> gene were sequenced in 68 patients infected with strain A(H1N1)pdm09. In a second phase of the study, the rs113350588 and rs1048479 polymorphisms identified in this sample were genotyped in a sample of 356 subjects from the northern and northeastern regions of Brazil with a diagnosis of pandemic influenza. Functional analysis of the polymorphisms was performed <i>in silico</i> and the influence of these variants on the severity of infection was evaluated. The results suggest that rs113350588 and rs1048479 may alter the function of ST3GAL1 either directly through splicing regulation alteration and/or indirectly through LD with SNP with regulatory function. In the study the rs113350588 and rs1048479 polymorphisms were in linkage disequilibrium in the population studied (D’ = 0.65). The GC haplotype was associated with an increased risk of death in subjects with influenza (OR = 4.632, 95% CI = 2.10;1.21). The AT haplotype was associated with an increased risk of severe disease and death (OR = 1.993, 95% CI = 1.09;3.61 and OR 4.476, 95% CI = 2.37;8.44, respectively). This study demonstrated for the first time the association of <i>ST3GAL1</i> gene haplotypes on the risk of more severe disease and death in patients infected with <i>Influenza A(H1N1)pdm09 virus</i>.</p></div

    Dissecting drivers of immune activation in chronic HIV-1 infection

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    Summary: Background: Immune activation is a significant contributor to HIV pathogenesis and disease progression. In virally-suppressed individuals on ART, low-level immune activation has been linked to several non-infectious comorbid diseases. However, studies have not been systematically performed in sub-Saharan Africa and thus the impact of demographics, ART and regional endemic co-infections on immune activation is not known. We therefore comprehensively evaluated in a large multinational African cohort markers for immune activation and its distribution in various settings. Methods: 2747 specimens from 2240 people living with HIV (PLWH) and 477 without HIV from the observational African Cohort Study (AFRICOS) were analyzed for 13 immune parameters. Samples were collected along with medical history, sociodemographic and comorbidity data at 12 HIV clinics across 5 programs in Uganda, Kenya, Tanzania and Nigeria. Data were analyzed with univariate and multivariate methods such as random forests and principal component analysis. Findings: Immune activation was markedly different between PLWH with detectable viral loads, and individuals without HIV across sites. Among viremic PLWH, we found that all immune parameters were significantly correlated with viral load except for IFN-α. The overall inflammatory profile was distinct between men and women living with HIV, in individuals off ART and with HIV viremia. We observed stronger differences in the immune activation profile with increasing viremia. Using machine learning methods, we found that geographic differences contributed to unique inflammatory profiles. We also found that among PLWH, age and the presence of infectious and/or noninfectious comorbidities showed distinct inflammatory patterns, and biomarkers may be used to predict the presence of some comorbidities. Interpretation: Our findings show that chronic immune activation in HIV-1 infection is influenced by HIV viral load, sex, age, region and ART use. These predictors, as well as associations among some biomarkers and coinfections, influence biomarkers associated with noncommunicable diseases. Funding: This work was supported by the President's Emergency Plan for AIDS Relief via a cooperative agreement between the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., and the U.S. Department of Defense [W81XWH-11-2-0174, W81XWH-18-2-0040]. The investigators have adhered to the policies for protection of human subjects as prescribed in AR 70–25. This article was prepared while Michael A. Eller was employed at Henry M. Jackson Foundation for the Advancement of Military Medicine for the U.S. Military HIV Research Program. The views expressed are those of the authors and should not be construed to represent the positions of the US Army or the Department of Defense. The opinions expressed in this article are the author's own, and do not reflect the view of the National Institutes of Health, the U.S. Department of Health and Human Services, or the U.S. government
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