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Creators/Authors contains: "Angel, Nicola"

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  1. null (Ed.)
    Abstract Background Wastewater-based epidemiology (WBE) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be an important source of information for coronavirus disease 2019 (COVID-19) management during and after the pandemic. Currently, governments and transportation industries around the world are developing strategies to minimize SARS-CoV-2 transmission associated with resuming activity. This study investigated the possible use of SARS-CoV-2 RNA wastewater surveillance from airline and cruise ship sanitation systems and its potential use as a COVID-19 public health management tool. Methods Aircraft and cruise ship wastewater samples (n = 21) were tested for SARS-CoV-2 using two virus concentration methods, adsorption–extraction by electronegative membrane (n = 13) and ultrafiltration by Amicon (n = 8), and five assays using reverse-transcription quantitative polymerase chain reaction (RT-qPCR) and RT-droplet digital PCR (RT-ddPCR). Representative qPCR amplicons from positive samples were sequenced to confirm assay specificity. Results SARS-CoV-2 RNA was detected in samples from both aircraft and cruise ship wastewater; however concentrations were near the assay limit of detection. The analysis of multiple replicate samples and use of multiple RT-qPCR and/or RT-ddPCR assays increased detection sensitivity and minimized false-negative results. Representative qPCR amplicons were confirmed for the correct PCR product by sequencing. However, differences in sensitivity were observed among molecular assays and concentration methods. Conclusions The study indicates that surveillance of wastewater from large transport vessels with their own sanitation systems has potential as a complementary data source to prioritize clinical testing and contact tracing among disembarking passengers. Importantly, sampling methods and molecular assays must be further optimized to maximize detection sensitivity. The potential for false negatives by both wastewater testing and clinical swab testing suggests that the two strategies could be employed together to maximize the probability of detecting SARS-CoV-2 infections amongst passengers. 
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  2. Abstract

    CD123hi CD11c− dendritic cells (CD123hi DC) are a distinct subset of human DC present in bone marrow, blood, lymphoid organs, and peripheral tissues. Pathogen stimulation, cytokine, or CD40 ligation induces CD123hi DC maturation, involving a shift from their innate immune to cognate antigen-presenting functions. In this study, we revealed that blood CD123hi DC in the presence of cytokine (granulocyte macrophage-colony stimulating factor and interleukin-3) undergo progressive, step-wise maturation through an “early” stage, delineated by expression of the antigen detected by the new monoclonal antibody CMRF58 (CD123hiCMRF58+CD40−CD86−CD83−) to the “late” stage with costimulatory antigen expression (CD123hiCMRF58+CD40+CD86+CD83+/−). In this early stage, cytokine-maintained CD123hi DC do not display changes in their morphology, no longer produce interferon-α (IFN-α) in response to bacteria, and develop the capacity to induce proliferation and polarization of allogeneic T cells. CD123hiCMRF58+ DC, phenotypically similar to in vitro cytokine-maintained CD123hi DC, were not detected in tonsil but are present in allergen-challenged nasal mucosa of allergic individuals. Thus, CD123hi DC in certain tissue environments such as allergen-challenged nasal mucosa share a common CD123hiCMRF58+ phenotype with in vitro cytokine-maintained blood CD123hi DC characterized by lack of IFN-α production.

     
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