RESUMEN
BACKGROUND: Natural killer (NK) cells are implicated in the pathogenesis of hepatitis C virus (HCV) infection and outcome of interferon (IFN)-α based therapy, although mechanisms remain unclear. METHODS: To evaluate NK ability to control HCV infection, we analyzed healthy donor and HCV-infected donor NK-cell cytolytic activity directed at HCV-infected target cells. RESULTS: HCV-infected subjects' natural cytotoxicity receptor (NCR)-dependent NK-cell cytolytic activity directed at HCV-infected and uninfected Huh7.5 target cells was greater than that of cells from healthy donors, and this localized to the African American subset. However, IFN-α-enhanced NK cytolytic function was lower in HCV-infected subjects, again localized mainly to the African American subset. Additionally, whereas HCV-infected Huh7.5 cells were more readily targeted than uninfected cells, the selectivity of cytolytic activity for infected targets was lower during HCV infection and after IFN-α stimulation, and lower selectivity was in part attributable to greater NKp46 expression. Furthermore, cytolytic activity was associated with higher serum aspartate aminotransferase, rs12979860 IL28B genotype, and in vivo response to pegylated IFN/ribavirin therapy. CONCLUSIONS: These data indicate that during chronic HCV infection, race-associated increase in NCR expression and IL28B-associated cytolytic activity may participate in host response to IFN-α-containing HCV therapy.
Asunto(s)
Hepacivirus/inmunología , Interferón-alfa/uso terapéutico , Interleucinas/metabolismo , Células Asesinas Naturales/fisiología , Hepatopatías/patología , Polietilenglicoles/uso terapéutico , Ribavirina/uso terapéutico , Adulto , Negro o Afroamericano , Antivirales/administración & dosificación , Antivirales/uso terapéutico , Femenino , Regulación de la Expresión Génica/inmunología , Hepatitis C/tratamiento farmacológico , Hepatitis C/inmunología , Hepatitis C/virología , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Interferones , Interleucinas/genética , Proteína 1 de la Membrana Asociada a los Lisosomas , Masculino , Persona de Mediana Edad , Polietilenglicoles/administración & dosificación , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/uso terapéutico , Ribavirina/administración & dosificaciónRESUMEN
BACKGROUND: Natural killer (NK) cells likely contribute to outcome of acute hepatitis C virus (HCV) infection and interferon (IFN)-induced control of chronic HCV infection. We previously observed IFN-αR and NKp30 expression associated with IFN-α-dependent NK cell activity. METHODS: Here, we examined CD16(+)56(-), CD16(+)56(+), and CD16(-)56(+) NK cell subset IFN-αR and NKp30 expression in relation to magnitude of HCV genotype 1 decrease during pegylated IFN-α plus ribavirin therapy. RESULTS: We observed greater baseline IFN-αR and NKp30 expression on CD16(+)56(+) and CD16(-)56(+) NK subsets in HCV-infected patients than in healthy control subjects. Baseline CD16(+)56(-) NK IFN-αR expression was associated with IFN-α-induced pSTAT1, and both were associated with magnitude of HCV decrease during pegylated IFN-α plus ribavirin therapy. Baseline CD16(+)56(-) NK IFN-αR expression was associated with race and interleukin 28B genotype, negatively associated with aspartate aminotransferase-to platelet ratio index, and positively associated with increase in NKp30 expression after in vivo IFN-α exposure. Finally, in vitro IFN-α2a-activated NK cytolysis of HCV-infected target cells was in part dependent on NKp30, and CD16(+)56(-) NK cell IFN-αR expression correlated with cytolytic activity. CONCLUSIONS: IFN-αR expression on CD16(+)56(-) NK cells during chronic HCV infection may in part be genetically determined, and level of expression regulates IFN-α signaling, which in turn may contribute to control of HCV infection.
Asunto(s)
Regulación de la Expresión Génica , Hepacivirus/inmunología , Hepatitis C Crónica/inmunología , Células Asesinas Naturales/inmunología , Receptor de Interferón alfa y beta/biosíntesis , Receptor de Interferón alfa y beta/inmunología , Transducción de Señal , Adulto , Anciano , Antivirales/administración & dosificación , Antígeno CD56/análisis , Femenino , Proteínas Ligadas a GPI/análisis , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/virología , Humanos , Interferón-alfa/administración & dosificación , Células Asesinas Naturales/química , Subgrupos Linfocitarios/química , Subgrupos Linfocitarios/inmunología , Masculino , Persona de Mediana Edad , Receptor 3 Gatillante de la Citotoxidad Natural/biosíntesis , Receptor 3 Gatillante de la Citotoxidad Natural/inmunología , Receptores de IgG/análisis , Resultado del TratamientoRESUMEN
Chronic hepatitis C virus (HCV) infection is associated with B cell activation, although underlying mechanisms are unclear. To investigate B cell regulation during HCV infection, we measured bulk B cell CpG and Staphylococcus aureus Cowan-induced IgG Ab-secreting cell (ASC) frequency, HCV and tetanus-specific ASC frequency, BCR- and CD40L-dependent CD80/CD86 expression, and activation of memory CD4 cells. Immature transitional, naive, resting memory, mature activated, tissue-like memory, and plasma B cell subset frequencies, cell cycling, and intrinsic apoptosis were quantified. We observed intact or enhanced tetanus-specific and total IgG ASC frequency, serum IgG, BCR- and CD40L-dependent CD80/CD86 expression, and CD40L-dependent bulk B cell activation of memory CD4 cells in HCV infection. HCV-specific ASCs were observed in HCV-infected but not control subjects, although frequencies were lower compared with tetanus-specific cells. Immature transitional and mature activated B cell subset frequencies were increased in HCV-infected subjects, with immature transitional frequency associated with liver inflammation and serum B cell-activating factor. Mature activated B cells less commonly expressed Ki67, more commonly expressed Bcl2, and were more intrinsically resistant to apoptosis, whereas immature transitional B cells more commonly expressed Ki67, the latter associated with plasma HCV level. Taken together, these results indicate that in the setting of chronic HCV infection, a state of activation results in B cell subset skewing that is likely the result of alterations in homeostasis, cell cycling, and intrinsic resistance to apoptosis and that results in an overall intact or enhanced B cell response to BCR and CD40L.
Asunto(s)
Apoptosis/inmunología , Subgrupos de Linfocitos B/inmunología , Subgrupos de Linfocitos B/patología , Ciclo Celular/inmunología , Hepatitis C/inmunología , Hepatitis C/patología , Inmunidad Innata , Activación de Linfocitos/inmunología , Factor Activador de Células B/sangre , Subgrupos de Linfocitos B/metabolismo , Diferenciación Celular/inmunología , Células Cultivadas , Hepatitis C/sangre , Humanos , Memoria Inmunológica , Inflamación/sangre , Inflamación/inmunología , Inflamación/patología , Recuento de Linfocitos , Proteínas Proto-Oncogénicas c-bcl-2/sangreRESUMEN
BACKGROUND: HIV infection contributes to accelerated rates of progression of liver fibrosis during hepatitis C virus (HCV) infection, and HCV liver disease contributes to mortality during HIV infection. Although mechanisms underlying these interactions are not well known, soluble and cellular markers of immune activation associate with disease progression during both infections. METHODS: We identified proteins varying in expression across the plasma proteomes of subjects with untreated HIV infection, untreated HCV infection with low aspartate transaminase/platelet ratio index, untreated HCV infection with high aspartate transaminase/platelet ratio index, HIV-HCV coinfection, and controls. We examined correlations between dysregulated proteins and markers of immune activation to uncover biomarkers specific to disease states. RESULTS: We observed the anticipated higher frequencies of HLA-DRCD38CD4 and CD8 T cells, higher serum soluble CD14 levels, and higher serum interleukin-6 levels for HCV- and HIV-infected groups compared with controls. Plasma proteome analysis identified 2297 peptides mapping to 227 proteins, and quantitative analysis of peptide intensity identified significant changes in 85 proteins across the 5 groups. Abundance for 7 of these proteins was validated by enzyme-linked immunosorbent assay. Forty-three of these proteins correlated with markers of immune activation, including at least 2 proteins that may directly drive T-cell activation. As a functional validation, we tested the enzymatic pathway product (lysophosphatidic acid, LPA) of one such protein, ecotonucleotide pyrophosphatase/phosphodiesterase-2, for ability to activate T cells in vitro. LPA activated T cells to express CD38 and HLA-DR. CONCLUSIONS: These data indicate that elevated levels of ecotonucleotide pyrophosphatase/phosphodiesterase-2 and LPA during advanced HCV disease may play a role in exacerbating immune activation during HCV-HIV coinfection.
Asunto(s)
Coinfección/inmunología , Infecciones por VIH/inmunología , Hepatitis C Crónica/inmunología , Plasma/química , Proteoma/análisis , Adulto , Biomarcadores/sangre , Coinfección/patología , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 2/sangre , Femenino , Infecciones por VIH/patología , Hepatitis C Crónica/patología , Humanos , Lisofosfolípidos/sangre , Masculino , Persona de Mediana EdadRESUMEN
Dendritic cells (DC) direct the magnitude, polarity and effector function of the adaptive immune response. DC express toll-like receptors (TLR), antigen capturing and processing machinery, and costimulatory molecules, which facilitate innate sensing and T cell activation. Once activated, DC can efficiently migrate to lymphoid tissue and prime T cell responses. Therefore, DC play an integral role as mediators of the immune response to multiple pathogens. Elucidating the molecular mechanisms involved in DC activation is therefore central in gaining an understanding of host response to infection. Unfortunately, technical constraints have limited system-wide 'omic' analysis of human DC subsets collected ex vivo. Here we have applied novel proteomic approaches to human myeloid dendritic cells (mDCs) purified from 100 mL of peripheral blood to characterize specific molecular networks of cell activation at the individual patient level, and have successfully quantified over 700 proteins from individual samples containing as little as 200,000 mDCs. The proteomic and network readouts after ex vivo stimulation of mDCs with TLR3 agonists are measured and verified using flow cytometry.