Project description:Understanding the molecular mechanisms of T cell exhaustion and reinvigoration is crucial to improving T cell based immunotherapy. In this study we confirmed key differences between memory and exhausted antigen-specific CD8+ T cells in hepatitis C virus infection before and after antiviral treatment. After viral cure, we observed the although phenotypically they seem to recover, functionally they showed little improvement and critical transcriptional regulators remained in exhausted state.
Project description:Investigation of phenotypical changes between exhausted HCV-specific CD8+ T cells during chronic infection and after DAA-mediated cure investigation of heterogeneity withhin the HCV-specific CD8+ T cell population
Project description:Investigation of phenotypical changes between exhausted HCV-specific CD8+ T cells during chronic infection and after DAA-mediated cure investigation of heterogeneity withhin the HCV-specific CD8+ T cell population
Project description:We dissect HCV imprinting of B cell repertoires in patients with chronic disease. The persistent character of the oncogenic B cell repertoire generated by HCV may point to a chronically elevated lymphoma risk in these patients even years after HCV cure.
Project description:We dissect HCV imprinting of B cell repertoires in patients with chronic disease. The persistent character of the oncogenic B cell repertoire generated by HCV may point to a chronically elevated lymphoma risk in these patients even years after HCV cure.
Project description:Chronic hepatitis C virus (HCV) infection is associated with CD8+ T-cell exhaustion characterized by limited effector functions and thus compromised anti-viral activity. Exhausted HCV-specific CD8+ T cells are comprised of memory-like and terminally exhausted CD8+ T-cell subsets. So far, little is not known about the molecular profile and fate of these cells after elimination of chronic antigen stimulation by direct acting antiviral therapy (DAA). Here, we report an antigen-driven molecular core signature underlying exhausted CD8+ T-cell subset heterogeneity in chronic viral infection with a progenitor/progeny relationship of memory-like and terminally exhausted HCV-specific CD8+ T cells via an intermediate stage. Furthermore, transcriptional profiling reveals that the memory-like cells remain after DAA-mediated cure while terminally exhausted HCV-specific CD8+ T-cell subsets are lost. Thus, the memory polarization of the overall HCV-specific CD8+ T-cell response after cure does not result from re-differentiation of exhausted T cells. Consequently, antigen elimination has little impact on the exhausted core signature of memory-like CD8+ T cells that remains clearly different from bona fide T-cell memory. These results identify a molecular signature of T-cell exhaustion that is imprinted like a chronic scar in HCV-specific CD8+ T cells even after HCV cure, highlighting the requirement of re-programming to elicit full effector potential of exhausted T cells.
Project description:After nerve injury, myelin and Remak Schwann cells reprogram to repair cells specialized for regeneration. Normally providing strong regenerative support, these cells fail in aging animals, and during the chronic denervation that results from slow axon growth. This impairs axonal regeneration and causes a significant clinical problem. We find that aging and chronically denervated repair cells express reduced c-Jun protein and the regenerative support provided by these cells is also reduced. In both cases, genetically restoring Schwann cell c-Jun levels restores regeneration to that in controls. We identify potential gene candidates mediating this effect and implicate Shh in the control of Schwann cell c-Jun levels. These experiments reveal that a common mechanism, reduced c-Jun in repair cells, underlies two major reasons for regeneration failure in the PNS. They underscore the central importance of Schwann cell c-Jun as a regulator of nerve repair, and point to molecular pathways that can be manipulated for improving the clinical outcome of nerve injuries.