Refine
Keywords
- HBV filaments (1)
- HBV genotypes (1)
- HBV surface protein (1)
- PreS1 deletion (1)
- arachidonic acid (1)
- exosomes (1)
- innate immunity (1)
- interferon (1)
- morphogenesis (1)
- omega-3 fatty acids (1)
- Is there an association between the H1N1 influenza pandemic vaccination and the manifestation of narcolepsy? (2015)
- After the mass-vaccination campaign during the influenza A (H1N1) 2009 pandemic, a significant increase in narcolepsy incidence was observed initially in Scandinavia, later in other European countries and recently also in Canada. Narcolepsy is a sleep disease caused by the loss of hypocretin-producing cells in the hypothalamus. Almost all narcolepsy patients carry the HLA-DQB1*0602 allele, giving a link to an autoimmune-mediated process. Most of the observed narcolepsy cases were correlated to the vaccination with Pandemrix, the most frequently used vaccine in the EU, and a slight connection to Arepanrix was also detected, which was distributed in Canada. Both vaccines were adjuvanted with AS03, suggesting a possible link between AS03 and narcolepsy. No narcolepsy cases were detected with MF59-adjuvanted or non-adjuvanted influenza vaccines. Recent studies reported differences between Pandemrix and Arepanrix and suggested the vaccine rather than the adjuvant as a suspect for narcolepsy development following vaccination. In addition, in China an increase of narcolepsy cases was reported to occur in absence of vaccination. Possible factors and potential additive effects that may have triggered narcolepsy after the pandemic vaccination are being reviewed in this paper.
- Macrophage-derived extracellular vesicles induce long-lasting immunity against Hepatitis C virus which is blunted by Polyunsaturated fatty acids (2018)
- Extracellular vesicles (EVs) are increasingly recognized as important mediators of intercellular communication. In this study, we aimed to further characterize the role of macrophage-derived EVs in immune responses against hepatitis C virus (HCV) and the potential of polyunsaturated fatty acids (PUFAs) to modulate this modality of innate immunity. To this end, EVs were isolated from interferon-stimulated macrophage cultures or from serum of patients with acute or chronic hepatitis C. EVs were characterized by electron microscopy, flow cytometry, RNA-sequencing, and Western blot analysis. The effect of EVs on replication of HCV was assessed in coculture models. Functional analyses were performed to assess the impact of PUFAs on EV-mediated antiviral immunity. We found that macrophages secreted various cytokines shortly after stimulation with type I and II IFN, which orchestrated a fast but short-lasting antiviral state. This rapid innate immune answer was followed by the production of macrophage-derived EVs, which induced a late, but long-lasting inhibitory effect on HCV replication. Of note, exposure of macrophages to PUFAs, which are important regulators of immune responses, dampened EV-mediated antiviral immune responses. Finally, EVs from patients with hepatitis C exhibited long-lasting antiviral activities during IFN therapy as well. The antiviral effect of EVs from Caucasian and Japanese patients differed, which may be explained by different nutritional uptake of PUFAs. In conclusion, our data indicate that macrophage-derived EVs mediate long-lasting inhibitory effects on HCV replication, which may bridge the time until efficient adaptive immune responses are established, and which can be blunted by PUFAs.
- The N-terminus makes the difference: impact of genotype-specific disparities in the N-terminal part of the hepatitis B virus large surface protein on morphogenesis of viral and subviral particles (2020)
- The N-terminus of the hepatitis B virus (HBV) large surface protein (LHB) differs with respect to genotypes. Compared to the amino terminus of genotype (Gt)D, in GtA, GtB and GtC, an additional identical 11 amino acids (aa) are found, while GtE and GtG share another similar 10 aa. Variants of GtB and GtC affecting this N-terminal part are associated with hepatoma formation. Deletion of these amino-terminal 11 aa in GtA reduces the amount of LHBs and changes subcellular accumulation (GtA-like pattern) to a dispersed distribution (GtD-like pattern). Vice versa, the fusion of the GtA-derived N-terminal 11 aa to GtD causes a GtA-like phenotype. However, insertion of the corresponding GtE-derived 10 aa to GtD has no effect. Deletion of these 11aa decreases filament size while neither the number of released viral genomes nor virion size and infectivity are affected. A negative regulatory element (aa 2–8) and a dominant positive regulatory element (aa 9–11) affecting the amount of LHBs were identified. The fusion of this motif to eGFP revealed that the effect on protein amount and subcellular distribution is not restricted to LHBs. These data identify a novel region in the N-terminus of LHBs affecting the amount and subcellular distribution of LHBs and identify release-promoting and -inhibiting aa residues within this motive.
