Engajamento entre políticos e seguidores no Facebook. O caso das eleições gerais de 2016 na Espanha

Las redes sociales han incorporado a la ciudadanía en la vida política, especialmente en periodos electorales. El objetivo de esta investigación es evaluar qué elementos de los mensajes difundidos por actores políticos en Facebook favorecen un mayor grado de engagement, apoyo y compromiso de los seguidores. Con las técnicas del análisis de contenido se examinan los posts publicados por PP, PSOE, Podemos y Ciudadanos, y sus respectivos candidatos, durante la campaña de las elecciones generales de 2016 en España. Los resultados indican que el grado de engagement es muy bajo, pese a registrarse niveles de interacción significativos.Social networks have incorporated citizens into political life, especially in electoral periods. The objective of this research is to evaluate which elements of the messages disseminated by politicians on Facebook favor a higher degree of engagement, support and commitment from followers. The posts published by PP, PSOE, Podemos and Ciudadanos, and their respective candidates are examined with the techniques of content analysis during the campaign of the 2016 general elections in Spain. The results indicate that the degree of engagement is very low, despite registering significant levels of interactio.As redes sociais incorporaram os cidadãos à vida política, especialmente nos períodos eleitorais. O objetivo desta pesquisa é avaliar quais elementos das mensagens divulgadas pelos atores políticos no Facebook favorecem um maior grau de engajamento, apoio e comprometimento dos seguidores. Com as técnicas de análise de conteúdo, se examinam os posts publicados pelo PP, PSOE, Podemos e Ciudadanos, e seus respectivos candidatos, durante a campanha das eleições gerais de 2016 na Espanha. Os resultados indicam que o grau de engajamento é muito baixo, apesar de registrar níveis significativos de interação

Connecting perception and production in early Catalan-Spanish bilingual children: language dominance and quality of input effects

This study investigates perception and production of the Catalan mid-vowel /e/-/ɛ/ contrast by two groups of 4.5-year-old Catalan-Spanish bilingual children, differing in language dominance. Perception was assessed with an XAB discrimination task involving familiar words and non-words. Production accuracy was measured using a familiar-word elicitation task. Overall, Catalan-dominant bilingual children outperformed Spanish-dominant bilinguals, the latter showing high variability in production accuracy, while being slightly above chance level in perception. No correlation between perception and production performance could be established in this group. The effect of language dominance alone could not explain the Spanish-dominant participants' performance, but quality of Catalan input (native vs. accented speech) was identified as an important factor behind familiar-word production and the inaccurate representation of the target contrast in the lexicon of the bilinguals' less-dominant language. More fine-grained measurements of experience-related factors are needed for a full understanding of the acquisition of challenging contrasts in bilingual contexts

Dendritic Cells From the Cervical Mucosa Capture and Transfer HIV-1 via Siglec-1

HIV-1; Siglec-1; CervixVIH-1; Siglec-1; CèrvixVIH-1; Siglec-1; CérvixAntigen presenting cells from the cervical mucosa are thought to amplify incoming HIV-1 and spread infection systemically without being productively infected. Yet, the molecular mechanism at the cervical mucosa underlying this viral transmission pathway remains unknown. Here we identified a subset of HLA-DR+ CD14+ CD11c+ cervical DCs at the lamina propria of the ectocervix and the endocervix that expressed the type-I interferon inducible lectin Siglec-1 (CD169), which promoted viral uptake. In the cervical biopsy of a viremic HIV-1+ patient, Siglec-1+ cells harbored HIV-1-containing compartments, demonstrating that in vivo, these cells trap viruses. Ex vivo, a type-I interferon antiviral environment enhanced viral capture and trans-infection via Siglec-1. Nonetheless, HIV-1 transfer via cervical DCs was effectively prevented with antibodies against Siglec-1. Our findings contribute to decipher how cervical DCs may boost HIV-1 replication and promote systemic viral spread from the cervical mucosa, and highlight the importance of including inhibitors against Siglec-1 in microbicidal strategies

Quercetin ameliorates dysregulation of lipid metabolism genes via the PI3K/AKT pathway in a diet-induced mouse model of non-alcoholic fatty liver disease

P. 879-893Flavonoids and related compounds seem to have favorable effects on nonalcoholic fatty liver disease (NAFLD) progression, although the exact mechanisms implicated are poorly understood. In this study, we aimed to investigate the effect of the flanovol quercetin on gene expression deregulation involved in the development of NAFLD, as well as the possible implication of phosphatidylinositol 3-kinase (PI3K)/AKT pathway modulatio

HIV-1 immune activation induces Siglec-1 expression and enhances viral trans-infection in blood and tissue myeloid cells

Background: Myeloid cells are key players in the recognition and response of the host against invading viruses. Paradoxically, upon HIV-1 infection, myeloid cells might also promote viral pathogenesis through trans-infection, a mechanism that promotes HIV-1 transmission to target cells via viral capture and storage. The receptor Siglec-1 (CD169) potently enhances HIV-1 trans-infection and is regulated by immune activating signals present throughout the course of HIV-1 infection, such as interferon α (IFNα). Results: Here we show that IFNα-activated dendritic cells, monocytes and macrophages have an enhanced ability to capture and trans-infect HIV-1 via Siglec-1 recognition of viral membrane gangliosides. Monocytes from untreated HIV-1-infected individuals trans-infect HIV-1 via Siglec-1, but this capacity diminishes after effective antiretroviral treatment. Furthermore, Siglec-1 is expressed on myeloid cells residing in lymphoid tissues, where it can mediate viral trans-infection. Conclusions: Siglec-1 on myeloid cells could fuel novel CD4+ T-cell infections and contribute to HIV-1 dissemination in vivo

Altered T-cell subset distribution in the viral reservoir in HIV-1-infected individuals with extremely low proviral DNA (LoViReTs)

HIV cure strategies aim to eliminate viral reservoirs that persist despite successful antiretroviral therapy (ART). We have previously described that 9% of HIV-infected individuals who receive ART harbor low levels of provirus (LoViReTs). We selected 22 LoViReTs matched with 22 controls ART suppressed for more than 3 years with fewer than 100 and more than 100 HIV-DNA copies/10 6 CD4 + T cells, respectively. We measured HIV reservoirs in blood and host genetic factors. Fourteen LoViReTs underwent leukapheresis to analyze replication-competent virus, and HIV-DNA in CD4 + T-cell subpopulations. Additionally, we measured HIV-DNA in rectum and/or lymph node biopsies from nine of them. We found that LoViReTs harbored not only lower levels of total HIV-DNA, but also significantly lower intact HIV-DNA, cell-associated HIV-RNA, and ultrasensitive viral load than controls. The proportion of intact versus total proviruses was similar in both groups. We found no differences in the percentage of host factors. In peripheral blood, 71% of LoViReTs had undetectable replication-competent virus. Minimum levels of total HIV-DNA were found in rectal and lymph node biopsies compared with HIV-infected individuals receiving ART. The main contributors to the reservoir were short-lived transitional memory and effector memory T cells (47% and 29%, respectively), indicating an altered distribution of the HIV reservoir in the peripheral T-cell subpopulations of LoViReTs. In conclusion, LoViReTs are characterized by low levels of viral reservoir in peripheral blood and secondary lymphoid tissues, which might be explained by an altered distribution of the proviral HIV-DNA towards more short-lived memory T cells. LoViReTs can be considered exceptional candidates for future interventions aimed at curing HIV

Dendritic Cells From the Cervical Mucosa Capture and Transfer HIV-1 via Siglec-1

Antigen presenting cells from the cervical mucosa are thought to amplify incoming HIV-1 and spread infection systemically without being productively infected. Yet, the molecular mechanism at the cervical mucosa underlying this viral transmission pathway remains unknown. Here we identified a subset of HLA-DR+ CD14+ CD11c+ cervical DCs at the lamina propria of the ectocervix and the endocervix that expressed the type-I interferon inducible lectin Siglec-1 (CD169), which promoted viral uptake. In the cervical biopsy of a viremic HIV-1+ patient, Siglec-1+ cells harbored HIV-1-containing compartments, demonstrating that in vivo, these cells trap viruses. Ex vivo, a type-I interferon antiviral environment enhanced viral capture and trans-infection via Siglec-1. Nonetheless, HIV-1 transfer via cervical DCs was effectively prevented with antibodies against Siglec-1. Our findings contribute to decipher how cervical DCs may boost HIV-1 replication and promote systemic viral spread from the cervical mucosa, and highlight the importance of including inhibitors against Siglec-1 in microbicidal strategies

Dissemination of <i>Mycobacterium tuberculosis</i> is associated to a <i>SIGLEC1</i> null variant that limits antigen exchange via trafficking extracellular vesicles

The identification of individuals with null alleles enables studying how the loss of gene function affects infection. We previously described a non‐functional variant in SIGLEC1, which encodes the myeloid‐cell receptor Siglec‐1/CD169 implicated in HIV‐1 cell‐to‐cell transmission. Here we report a significant association between the SIGLEC1 null variant and extrapulmonary dissemination of Mycobacterium tuberculosis (Mtb) in two clinical cohorts comprising 6,256 individuals. Local spread of bacteria within the lung is apparent in Mtb‐infected Siglec‐1 knockout mice which, despite having similar bacterial load, developed more extensive lesions compared to wild type mice. We find that Siglec‐1 is necessary to induce antigen presentation through extracellular vesicle uptake. We postulate that lack of Siglec‐1 delays the onset of protective immunity against Mtb by limiting antigen exchange via extracellular vesicles, allowing for an early local spread of mycobacteria that increases the risk for extrapulmonary dissemination

Identification of Siglec-1 null individuals infected with HIV-1

Siglec-1/CD169 is a myeloid-cell surface receptor critical for HIV-1 capture and infection of bystander target cells. To dissect the role of SIGLEC1 in natura, we scan a large population genetic database and identify a loss-of-function variant (Glu88Ter) that is found in ∼1% of healthy people. Exome analysis and direct genotyping of 4,233 HIV-1-infected individuals reveals two Glu88Ter homozygous and 97 heterozygous subjects, allowing the analysis of ex vivo and in vivo consequences of SIGLEC1 loss-of-function. Cells from these individuals are functionally null or haploinsufficient for Siglec-1 activity in HIV-1 capture and trans-infection ex vivo. However, Siglec-1 protein truncation does not have a measurable impact on HIV-1 acquisition or AIDS outcomes in vivo. This result contrasts with the known in vitro functional role of Siglec-1 in HIV-1 trans-infection. Thus, it provides evidence that the classical HIV-1 infectious routes may compensate for the lack of Siglec-1 in fuelling HIV-1 dissemination within infected individuals

Kinetics of immune responses elicited after three mRNA COVID-19 vaccine doses in predominantly antibody-deficient individuals

Mass vaccination campaigns reduced COVID-19 incidence and severity. Here, we evaluated the immune responses developed in SARS-CoV-2-uninfected patients with predominantly antibody-deficiencies (PAD) after three mRNA-1273 vaccine doses. PAD patients were classified based on their immunodeficiency: unclassified primary antibody-deficiency (unPAD, n = 9), common variable immunodeficiency (CVID, n = 12), combined immunodeficiency (CID, n = 1), and thymoma with immunodeficiency (TID, n = 1). unPAD patients and healthy controls (HCs, n = 10) developed similar vaccine-induced humoral responses after two doses. However, CVID patients showed reduced binding and neutralizing titers compared to HCs. Of interest, these PAD groups showed lower levels of Spike-specific IFN-γ-producing cells. CVID individuals also presented diminished CD8+T cells. CID and TID patients developed cellular but not humoral responses. Although the third vaccine dose boosted humoral responses in most PAD patients, it had limited effect on expanding cellular immunity. Vaccine-induced immune responses in PAD individuals are heterogeneous, and should be immunomonitored to define a personalized therapeutic strategies.info:eu-repo/semantics/publishedVersio