Biochemical, virological and immunological course of acute hepatitis C in asymptomatic patients with spontaneous clearance: patients with spontaneous clearance in the absence of anti-HCV

<p><b>Copyright information:</b></p><p>Taken from "Clearance of low levels of HCV viremia in the absence of a strong adaptive immune response"</p><p>http://www.virologyj.com/content/4/1/58</p><p>Virology Journal 2007;4():58-58.</p><p>Published online 11 Jun 2007</p><p>PMCID:PMC1914341.</p><p></p> HCV-RNA levels, ALT levels and T cell responses are shown. Coloured bars show the sum of SI values of the proliferation assay and the sum of specific interferon-gamma spots (spots in the presence of antigen – spots in the medium control) against 5 individual HCV proteins (HCV-core, HCV-NS3, HCV-helicase, HCV-NS4, HCV-NS5a). In addition, the number of individual proteins tested positive at the respective time point is shown for each assay. Interferon gamma ELISPOT responses were also tested against a panel of synthetic peptides representing class I and class II T cell epitopes derived from conserved regions of HCV with a cumulative HLA coverage > 85%. These assays were performed in an independent second laboratory ("Pep-Screen ELISPOT"; Vienna lab). The number of peptides tested positive in this assay is also given

Biochemical, virological and immunological course of acute hepatitis C in asymptomatic patients with spontaneous clearance: patients who developed anti-HCV antibodies

<p><b>Copyright information:</b></p><p>Taken from "Clearance of low levels of HCV viremia in the absence of a strong adaptive immune response"</p><p>http://www.virologyj.com/content/4/1/58</p><p>Virology Journal 2007;4():58-58.</p><p>Published online 11 Jun 2007</p><p>PMCID:PMC1914341.</p><p></p

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<p>Human γδ T cells can contribute to clearance of hepatitis C virus (HCV) infection but also mediate liver inflammation. This study aimed to understand the clonal distribution of γδ T cells in peripheral blood of chronic HCV patients and following HCV clearance by interferon-free direct-acting antiviral drug therapies. To this end, γδ T cell receptor (TCR) repertoires were monitored by mRNA-based next-generation sequencing. While the percentage of Vγ9⁺ T cells was higher in patients with elevated liver enzymes and a few expanded Vδ3 clones could be identified in peripheral blood of 23 HCV-infected non-cirrhotic patients, overall clonality and complexity of γδ TCR repertoires were largely comparable to those of matched healthy donors. Monitoring eight chronic HCV patients before, during and up to 1 year after therapy revealed that direct-acting antiviral (DAA) drug therapies induced only minor alterations of TRG and TRD repertoires of Vγ9⁺ and Vγ9⁻ cells. Together, we show that peripheral γδ TCR repertoires display a high stability (1) by chronic HCV infection in the absence of liver cirrhosis and (2) by HCV clearance in the course of DAA drug therapy.</p

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<p>Human γδ T cells can contribute to clearance of hepatitis C virus (HCV) infection but also mediate liver inflammation. This study aimed to understand the clonal distribution of γδ T cells in peripheral blood of chronic HCV patients and following HCV clearance by interferon-free direct-acting antiviral drug therapies. To this end, γδ T cell receptor (TCR) repertoires were monitored by mRNA-based next-generation sequencing. While the percentage of Vγ9⁺ T cells was higher in patients with elevated liver enzymes and a few expanded Vδ3 clones could be identified in peripheral blood of 23 HCV-infected non-cirrhotic patients, overall clonality and complexity of γδ TCR repertoires were largely comparable to those of matched healthy donors. Monitoring eight chronic HCV patients before, during and up to 1 year after therapy revealed that direct-acting antiviral (DAA) drug therapies induced only minor alterations of TRG and TRD repertoires of Vγ9⁺ and Vγ9⁻ cells. Together, we show that peripheral γδ TCR repertoires display a high stability (1) by chronic HCV infection in the absence of liver cirrhosis and (2) by HCV clearance in the course of DAA drug therapy.</p

Image_1.PDF

<p>Human γδ T cells can contribute to clearance of hepatitis C virus (HCV) infection but also mediate liver inflammation. This study aimed to understand the clonal distribution of γδ T cells in peripheral blood of chronic HCV patients and following HCV clearance by interferon-free direct-acting antiviral drug therapies. To this end, γδ T cell receptor (TCR) repertoires were monitored by mRNA-based next-generation sequencing. While the percentage of Vγ9⁺ T cells was higher in patients with elevated liver enzymes and a few expanded Vδ3 clones could be identified in peripheral blood of 23 HCV-infected non-cirrhotic patients, overall clonality and complexity of γδ TCR repertoires were largely comparable to those of matched healthy donors. Monitoring eight chronic HCV patients before, during and up to 1 year after therapy revealed that direct-acting antiviral (DAA) drug therapies induced only minor alterations of TRG and TRD repertoires of Vγ9⁺ and Vγ9⁻ cells. Together, we show that peripheral γδ TCR repertoires display a high stability (1) by chronic HCV infection in the absence of liver cirrhosis and (2) by HCV clearance in the course of DAA drug therapy.</p

High incidence of AFN in PV+LCMV double immune mice following PV re-challenge.

<p>(A) Naïve, PV-immune, and (PV+LCMV WT) double immune mice were re-challenged with PV, sacrificed 3 days PI, and the severity of AFN in the visceral fat pads was assessed. (*) indicates <i>p</i>&lt;.05 in frequency of AFN using the Kruskai-Wallis test (one-way ANOVA non-parametric). (B), (C), and (D) represent experiments performed using the LCMV clone 13 system and its naturally derived V207A mutant. (B) Domination of NP205-specific CD8 T cells in PV+Clone 13 LCMV WT double immune mice. PBL were collected from double-immune mice, before the final challenge with PV, and stimulated with peptides <i>ex vivo</i> in a standard ICS assay. These are representative frequencies of the IFNγ positive CD8α+ T cells from 4 independent experiments using 5 mice per group. (C) Incidence of AFN after PV challenge. Naïve, (PV+Clone 13 LCMV WT), and (PV+Clone 13 LCMV NP-V207A) double immune mice re-challenged with PV were sacrificed 4 days PI, and the severity of AFN in the visceral fat pads was assessed. Compilation of data from 4 independent experiments. (*) and (***) indicate <i>p</i>&lt;.05 and <i>p</i>&lt;.0001, respectively. (D) Domination of cross-reactive NP205-specific CD8 T cells isolated from the visceral fat pad of (PV+Clone 13 LCMV WT) double immune mice following PV re-challenge. Standard ICS and FACs analyses were performed. Numbers are representative frequencies of IFNγ+, CD8α+ T cells from two similar experiments.</p

Lack of MHC stabilization by LCMV NP L212A.

<p>MHC stabilization assays for LCMV WT (NP205) and mutant (L212A) peptides. RMA-S cells were incubated with different concentrations of peptides and stained against H2K^b to detect its stabilization on the cell surface.</p

In vitro functionality of peripheral blood NK cells.

<p>NK cells from healthy individuals (n = 11) were stimulated for 6 hours with different concentration of RBV, PEG-IFNa and combination of both. (A) Representative FACS plots for NK cells stimulated with K562 target cells alone, with K562 target cells and RBV, with K562 target cells and PEG-IFNa, or with K562 target cells and combination of both are depicted. (B) Mean values of CD107a, IFNg and TNF expression on total NK cells upon stimulation with K562 target cells (B) and Huh7.5 hepatoma cells (C) from all healthy individuals.</p

Overall outcome of the evaluation process and treatment period.

<p>Overall outcome of the evaluation process and treatment period.</p

Baseline characteristics of patients with and without treatment failure until week 12.

<p>N/A: not available; n.d.: not differentiated; SD: standard deviation.</p