1,721,144 research outputs found
Analysis of in vivo dynamics of influenza virus infection in mice using a GFP reporter virus.
No full textInfluenza A virus is being extensively studied because of its major impact on human and animal health. However, the dynamics of influenza virus infection and the cell types infected in vivo are poorly understood. These characteristics are challenging to determine, partly because there is no efficient replication-competent virus expressing an easily traceable reporter gene. Here, we report the generation of a recombinant influenza virus carrying a GFP reporter gene in the NS segment (NS1-GFP virus). Although attenuated when compared with wild-type virus, the NS1-GFP virus replicates efficiently in murine lungs and shows pathogenicity in mice. Using whole-organ imaging and flow cytometry, we have tracked the dynamics of influenza virus infection progression in mice. Imaging of murine lungs shows that infection starts in the respiratory tract in areas close to large conducting airways and later spreads to deeper sections of the lungs. In addition to epithelial cells, we found GFP-positive antigen-presenting cells, such as CD11b(+)CD11c(-), CD11b(-)CD11c(+), and CD11b(+)CD11c(+), as early as 24 h after intranasal infection. In addition, a significant proportion of NK and B cells were GFP positive, suggesting active infection of these cells. We next tested the effects of the influenza virus inhibitors oseltamivir and amantadine on the kinetics of in vivo infection progression. Treatment with oseltamivir dramatically reduced influenza infection in all cell types, whereas, surprisingly, amantadine treatment more efficiently blocked infection in B and NK cells. Our results demonstrate high levels of immune cells harboring influenza virus antigen during viral infection and cell-type-specific effects upon treatment with antiviral agents, opening additional avenues of research in the influenza virus field
Analysis of in vivo dynamics of influenza virus infection using a GFP reporter virus.
No full textInfluenza A virus Is being extensively studied due to its major Impact in human and animal health. However, the dynamics of Influenza virus Infection and the cell types infected In vivo are poorly understood. These characteristics are not easy to determine parUy because currently there Is no replication-competent virus expressing a fluorescent reporter gene. Here, we report the generation of a complete Influenza virus carrying a GFP reporter gene In the NS segment of its genome (NS1-GFP virus). NS1-GFP virus replicates efficiently in cell culture and shows pathogenicity In mice at levels similar to parental virus. We have analyzed the In vivo dynamics of influenza Infection progression in mice by flow cytometry and whole organ Imaging of infected lungs. Using flow cytometric analysis of infected lungs, apart from epithelial cells, we find antigen presenting cells like CD11c+, CD11b+ CD11c+, CD11b+ and B cells to be GFP positive. In addition, NK cells are susceptible to Influenza Infection. Whole organ imaging of lungs show that influenza infection starts In the respiratory tract In areas closer to large conducting airways and with time spreads to deeper sections of the lungs. We have also tested the effects of oseltamivir and amantadine on the kinetics and In vivo infection progression in mice and find Interesting differences In the effects of these antivirals. Treatment with oseltamlvlr dramatically reduces Influenza Infection in all cell types, whereas, Interestingly, amantadine treatment blocks infection In a cell type specific manner
Learning immunology from the yellow fever vaccine: innate immunity to systems vaccinology
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Blimp1: Driving terminal differentiation to a T
No full textB lymphocyte maturation-induced protein-1 (Blimp1) is a transcrip-tional repressor expressed in diverse cell types. In the adaptive immune system, Blimp1 is expressed in lymphocytes that have undergone effector differentiation. Blimp1 is a master regulator of plasma cell differentiation and plays important roles in controlling T cell homeostasis and effector differentiation. Blimp1 can be induced by a variety of cytokines including IL-2, IL-4, IL-12, and IL-21 in addition to TCR and co-stimulatory signals. Blimp1-deficient mice develop spontaneous inflammatory disease mediated by infiltration of activated T cells into tissues. During immune responses Blimp1 is required for the differentiation of plasma cells as well as short-lived CD8 cytotoxic T cells. Mounting evidence suggests that Blimp1 plays a common role in the terminal differentiation of multiple cell subsets
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