Publications by authors named "K Heim"

Hepatitis B virus (HBV)-specific CD8 T cells play a dominant role during acute-resolving HBV infection but are functionally impaired during chronic HBV infection in humans. These functional deficits have been linked with metabolic and phenotypic heterogeneity, but it has remained unclear to what extent different subsets of HBV-specific CD8 T cells still suppress viral replication. We addressed this issue by deep profiling, functional testing and perturbation of HBV-specific CD8 T cells during different phases of chronic HBV infection.

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HBV-specific CD8+ T cells are only present at the low frequency during chronic infection. Thus, they are often undetectable by conventional ex vivo staining methods using peptide-loaded HLA class I tetramers. Detection sensitivity can be increased by magnetic bead-based enrichment strategies following staining with peptide-loaded HLA class I tetramers.

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Article Synopsis
  • - Chronic hepatitis B virus (HBV) infection affects 300 million people globally, leading to dysfunction in virus-specific CD8 T cells that struggle to eliminate HBV-infected liver cells due to mechanisms that aren't fully understood.
  • - Research indicates a liver immune rheostat inhibits the activation of these CD8 T cells, particularly the CXCR6 subtype, leading to loss of their functionality, as shown by increased activity of the transcription factor cAMP-responsive element modulator (CREM) in both experimental models and chronic HBV patients.
  • - Enhanced signaling pathways related to cAMP and protein kinase A (PKA) in these T cells contribute to their dysfunction, as they establish prolonged contacts with liver cells, impairing essential activation
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Bioaccessibility of metals from substances and alloys is increasingly used as part of the assessment to predict potential toxicity. However, data are sparse on the metal bioaccessibility from nanoparticle (NP) size metal substances. This study examines nickel ion release from metallic nickel and nickel oxide micron particles (MPs) and NPs in simulated biological fluids at various timepoints including those relevant for specific routes of exposure.

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