Role of the C-terminal domain of the HIV-1 glycoprotein in cell-to-cell viral transmission between T lymphocytes

<p>Abstract</p> <p>Background</p> <p>Mutant HIV (HIV-Env-Tr712) lacking the cytoplasmic tail of the viral glycoprotein (Env-CT) exhibits a cell-type specific replication phenotype such that replicative spread occurs in some T-cell lines (referred to as permissive cells) but fails to do so in most T-cell lines or in PBMCs (referred to as non-permissive cells). We aim to gain insight on the underlying requirement for the Env-CT for viral spread in non-permissive cells.</p> <p>Results</p> <p>We established that in comparison to HIV-Wt, both cell-free and cell-to-cell transmission of mutant HIV-Env-Tr712 from non-permissive cells were severely impaired under naturally low infection conditions. This requirement for Env-CT could be largely overcome by using saturating amounts of virus for infection. We further observed that in permissive cells, which supported both routes of mutant virus transmission, viral gene expression levels, Gag processing and particle release were inherently higher than in non-permissive cells, a factor which may be significantly contributing to their permissivity phenotype. Additionally, and correlating with viral transfer efficiencies in these cell types, HIV-Gag accumulation at the virological synapse (VS) was reduced to background levels in the absence of the Env-CT in conjugates of non-permissive cells but not in permissive cells.</p> <p>Conclusions</p> <p>During natural infection conditions, the HIV-Env-CT is critically required for viral transmission in cultures of non-permissive cells by both cell-free and cell-to-cell routes and is instrumental for Gag accumulation to the VS. The requirement of the Env-CT for these related processes is abrogated in permissive cells, which exhibit higher HIV gene expression levels.</p

Socioeconomic position and SARS-CoV-2 infections: seroepidemiological findings from a German nationwide dynamic cohort

Background Evidence on the relationship between socioeconomic position (SEP) and infections with SARS-CoV-2 is still limited as most of the available studies are ecological in nature. This is the first German nationwide study to examine differences in the risk of SARS-CoV-2 infections according to SEP at the individual level. Methods The ‘CORONA-MONITORING bundesweit’ (RKI-SOEP) study is a seroepidemiological survey among a dynamic cohort of the German adult population (n=15 122; October 2020–February 2021). Dried blood samples were tested for SARS-CoV-2 antibodies and oral-nasal swabs for viral RNA. SEP was measured by education and income. Robust logistic regression was used to examine adjusted associations of SARS-CoV-2 infections with SEP. Results 288 participants were seropositive, PCR positive or self-reported a previous laboratory-confirmed SARS-CoV-2 infection. The adjusted odds of SARS-CoV-2 infection were 1.87-fold (95% CI 1.06 to 3.29) higher among low-educated than highly educated adults. Evidence was weaker for income differences in infections (OR=1.65; 95% CI 0.89 to 3.05). Highly educated adults had lower odds of undetected infection. Conclusion The results indicate an increased risk of SARS-CoV-2 infection in low-educated groups. To promote health equity in the pandemic and beyond, social determinants should be addressed more in infection protection and pandemic planning

Socioeconomic position and SARS-CoV-2 infections: seroepidemiological findings from a German nationwide dynamic cohort

Background: Evidence on the relationship between socioeconomic position (SEP) and infections with SARS-CoV-2 is still limited as most of the available studies are ecological in nature. This is the first German nationwide study to examine differences in the risk of SARS-CoV-2 infections according to SEP at the individual level. Methods: The ‘CORONA-MONITORING bundesweit’ (RKI-SOEP) study is a seroepidemiological survey among a dynamic cohort of the German adult population (n=15 122; October 2020–February 2021). Dried blood samples were tested for SARS-CoV-2 antibodies and oral-nasal swabs for viral RNA. SEP was measured by education and income. Robust logistic regression was used to examine adjusted associations of SARS-CoV-2 infections with SEP. Results: 288 participants were seropositive, PCR positive or self-reported a previous laboratory-confirmed SARS-CoV-2 infection. The adjusted odds of SARS-CoV-2 infection were 1.87-fold (95% CI 1.06 to 3.29) higher among low-educated than highly educated adults. Evidence was weaker for income differences in infections (OR=1.65; 95% CI 0.89 to 3.05). Highly educated adults had lower odds of undetected infection. Conclusion: The results indicate an increased risk of SARS-CoV-2 infection in low-educated groups. To promote health equity in the pandemic and beyond, social determinants should be addressed more in infection protection and pandemic planning.German Research FoundationGerman Federal Ministry of HealthPeer Reviewe

Modest Attenuation of HIV-1 Vpu Alleles Derived from Elite Controller Plasma

In the absence of antiretroviral therapy, infection with human immunodeficiency virus type 1 (HIV-1) can typically not be controlled by the infected host and results in the development of acquired immunodeficiency. In rare cases, however, patients spontaneously control HIV-1 replication. Mechanisms by which such elite controllers (ECs) achieve control of HIV-1 replication include particularly efficient immune responses as well as reduced fitness of the specific virus strains. To address whether polymorphisms in the accessory HIV-1 protein Vpu are associated with EC status we functionally analyzed a panel of plasma-derived vpu alleles from 15 EC and 16 chronic progressor (CP) patients. Antagonism of the HIV particle release restriction by the intrinsic immunity factor CD317/tetherin was well conserved among EC and CP Vpu alleles, underscoring the selective advantage of this Vpu function in HIV-1 infected individuals. In contrast, interference with CD317/tetherin induced NF-κB activation was little conserved in both groups. EC Vpus more frequently displayed reduced ability to downregulate cell surface levels of CD4 and MHC class I (MHC-I) molecules as well as of the NK cell ligand NTB-A. Polymorphisms potentially associated with high affinity interactions of the inhibitory killer immunoglobulin-like receptor (KIR) KIR2DL2 were significantly enriched among EC Vpus but did not account for these functional differences. Together these results suggest that in a subgroup of EC patients, some Vpu functions are modestly reduced, possibly as a result of host selection

First geochemical and geochronological characterization of Late Cretaceous mesosilicic magmatism in Gastre, Northern Patagonia, and its tectonic relation to other coeval volcanic rocks in the region

Fil: Zaffarana, Claudia B. Consejo Nacional de Investigaciones Científicas y Técnicas. Buenos Aires, Argentina.Fil: Lagorio, Silvia L. Servicio Geológico Minero Argentino (SEGEMAR). Buenos Aires, Argentina.Fil: Orts, Darío L. Consejo Nacional de Investigaciones Científicas y Técnicas. Buenos Aires, Argentina.Fil: Busteros, Alicia. Servicio Geológico Minero Argentino (SEGEMAR); Argentina.Fil: Silva Nieto, Diego G. Servicio Geológico Minero Argentino (SEGEMAR). Buenos Aires, Argentina.Fil: Giacosa, Raúl E. Servicio Geológico Minero Argentino (SEGEMAR). Buenos Aires, Argentina.Fil: Ruiz González, Víctor. Universidad de Buenos Aires. Departamento de Geología de la FCEyN. Buenos Aires, Argentina.Fil: Boltshauser, Bárbara. Universidad Nacional de Río Negro. Río Negro, Argentina.Fil: Puigdomenech Negre, Carla G. Universidad de Buenos Aires. Departamento de Geología de la FCEyN. Buenos Aires, Argentina.Fil: Somoza, Rubén. Universidad de Buenos Aires. Departamento de Geología de la FCEyN. Buenos Aires, Argentina.Fil: Haller, Miguel. Universidad Nacional de la Patagonia San Juan Bosco. Comodoro Rivadavia, Argentina.Fil: Zaffarana, Claudia B. Universidad Nacional de Río Negro. Río Negro, Argentina.Fil: Orts, Darío L. Universidad Nacional de Río Negro. Río Negro, Argentina.Fil: Giacosa, Raúl E. Universidad Nacional de Río Negro. Río Negro, Argentina.Fil: Ruiz González, Víctor. Consejo Nacional de Investigaciones Científicas y Técnicas. Buenos Aires, Argentina.Fil: Boltshauser, Bárbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Buenos Aires, Argentina.Fil: Puigdomenech Negre, Carla G. Consejo Nacional de Investigaciones Científicas y Técnicas. Buenos Aires, Argentina.Fil: Somoza, Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas. Buenos Aires, Argentina.Fil: Haller, Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Buenos Aires, Argentina.This work characterizes Late Cretaceous calc-alkaline volcanic rocks in Gastre, Northern Patagonia, Argentina. These newly found porphyritic rocks bear an 40Ar–39Ar amphibole age of ∼ 74–76 Ma, a subduction-type geochemical signature and a deep, garnet-bearing source. Extruded in a stage of low magmatic activity in the Northern Patagonian Andes (∼ 41–44° S), they could represent an eastward migration of the Late Cretaceous magmatic arc that was associated with a regional compressive deformational stage in the South American margin.

Defects in III-N LEDs: experimental identification and impact on electro-optical characteristics

III-N light-emitting-diodes (LEDs) are subject of intense investigations, thanks to their high efficiency and great reliability. The quality of the semiconductor material has a significant impact on the electro-optical performance of LEDs: for this reason, a detailed characterization of defect properties and the modeling of the impact of defects on device performance are of fundamental importance. This presentation addresses this issue, by discussing a set of recent case studies on the topic; specifically, we focus on the experimental characterization of defects, and on the modeling of their impact on the electro-optical characteristics of the devices