Decrease of T-cells exhaustion markers programmed cell death-1 and T-cell immunoglobulin and mucin domain-containing protein 3 and plasma IL-10 levels after successful treatment of chronic hepatitis C

During chronic hepatitis C virus (HCV) infection, both CD4$^{+}$ and CD8$^{+}$ T-cells become functionally exhausted, which is reflected by increased expression of programmed cell death-1 (PD-1) and T-cell immunoglobulin and mucin domain-containing protein 3 (Tim-3), and elevated anti-inflammatory interleukin 10 (IL-10) plasma levels. We studied 76 DAA-treated HCV-positive patients and 18 non-infected controls. Flow cytometry measured pretreatment frequencies of CD4$^{+}$PD-1$^{+}$, CD4$^{+}$PD-1$^{+}$Tim-3$^{+}$ and CD8$^{+}$PD-1$^{+}$Tim-3$^{+}$ T-cells and IL-10 levels measured by ELISA were significantly higher and CD4$^{+}$PD-1$^{-}$Tim-3$^{-}$ and CD8$^{+}$PD-1$^{-}$Tim-3$^{-}$ T-cells were significantly lower in patients than in controls. Treatment resulted in significant decrease of CD4$^{+}$Tim-3$^{+}$, CD8$^{+}$Tim-3$^{+}$, CD4$^{+}$PD-1$^{+}$Tim-3$^{+}$ and CD8$^{+}$PD-1$^{+}$Tim-3$^{+}$ T-cell frequencies as well as IL-10 levels and increase in CD4$^{+}$PD-1$^{-}$Tim-3$^{-}$ and CD8$^{+}$PD-1$^{-}$Tim-3$^{-}$ T-cells. There were no significant changes in the frequencies of CD4$^{+}$PD-1$^{+}$ T-cells, while CD8$^{+}$PD-1$^{+}$ T-cells increased. Patients with advanced liver fibrosis had higher PD-1 and lower Tim-3 expression on CD4$^{+}$T-cells and treatment had little or no effect on the exhaustion markers. HCV-specific CD8$^{+}$T-cells frequency has declined significantly after treatment, but their PD-1 and Tim-3 expression did not change. Successful treatment of chronic hepatitis C with DAA is associated with reversal of immune exhaustion phenotype, but this effect is absent in patients with advanced liver fibrosis

Hepatitis C Virus Neuroinvasion: Identification of Infected Cells▿

Hepatitis C virus (HCV) infection often is associated with cognitive dysfunction and depression. HCV sequences and replicative forms were detected in autopsy brain tissue and cerebrospinal fluid from infected patients, suggesting direct neuroinvasion. However, the phenotype of cells harboring HCV in brain remains unclear. We studied autopsy brain tissue from 12 HCV-infected patients, 6 of whom were coinfected with human immunodeficiency virus. Cryostat sections of frontal cortex and subcortical white matter were stained with monoclonal antibodies specific for microglia/macrophages (CD68), oligodendrocytes (2′,3′-cyclic nucleotide 3′-phosphodiesterase), astrocytes (glial fibrillary acidic protein [GFAP]), and neurons (neuronal-specific nuclear protein); separated by laser capture microscopy (LCM); and tested for the presence of positive- and negative-strand HCV RNA. Sections also were stained with antibodies to viral nonstructural protein 3 (NS3), separated by LCM, and phenotyped by real-time PCR. Finally, sections were double stained with antibodies specific for the cell phenotype and HCV NS3. HCV RNA was detected in CD68-positive cells in eight patients, and negative-strand HCV RNA, which is a viral replicative form, was found in three of these patients. HCV RNA also was found in astrocytes from three patients, but negative-strand RNA was not detected in these cells. In double immunostaining, 83 to 95% of cells positive for HCV NS3 also were CD68 positive, while 4 to 29% were GFAP positive. NS3-positive cells were negative for neuron and oligodendrocyte phenotypic markers. In conclusion, HCV infects brain microglia/macrophages and, to a lesser extent, astrocytes. Our findings could explain the biological basis of neurocognitive abnormalities in HCV infection