Ferritin heavy chain is the host factor responsible for HCV-induced inhibition of apoB-100 production and is required for efficient viral infection.

Hepatic fat export occurs by apolipoprotein B-100-containing lipoprotein production, whereas impaired production leads to liver steatosis. Hepatitis C virus (HCV) infection is associated to dysregulation of apoB-100 secretion and steatosis; however, the molecular mechanism by which HCV affects the apoB-100 secretion is not understood. Here, combining quantitative proteomics and computational biology, we propose ferritin heavy chain (Fth) as being the cellular determinant of apoB-100 production inhibition. By means of molecular analyses, we found that HCV nonstructural proteins and NS5A appear to be sufficient for inducing Fth up-regulation. Fth in turn was found to inhibit apoB-100 secretion leading to increased intracellular degradation via proteasome. Notably, intracellular Fth down-regulation by siRNA restores apoB-100 secretion. The inverse correlation between ferritin and plasma apoB-100 concentrations was also found in JFH-1 HCV cell culture systems (HCVcc) and HCV-infected patients. Finally, Fth expression was found to be required for robust HCV infection. These observations provide a further molecular explanation for the onset of liver steatosis and allow for hypothesizing on new therapeutic and antiviral strategies.

Role of serum free light chains in predicting HIV-associated non-Hodgkin lymphoma and Hodgkin's lymphoma and its correlation with antiretroviral therapy.

A nested case-control study was performed within the Italian cohort of naïve to antiretroviral human immunodeficiency virus (HIV) patients (ICONA) cohort to evaluate the role of serum free light chains (sFLC) in predicting non-Hodgkin's lymphoma (NHL) and Hodgkin lymphoma (HL) in HIV-infected individuals. Of 6513 participants, 86 patients developed lymphoma and 46 of these (NHL, 30; HL, 16) were included in this analysis having stored prediagnostic blood. A total of 46 serum case samples matched 1:1 to lymphoma-free serum control samples were assayed for κ and λ sFLC levels and compared by using conditional logistic regression. Because the polyclonal nature of free light chains (FLCs) was the focus of our study, we introduced the k + λ sum as the measurement of choice and as the primary variable studied. κ + λ sFLC values were significantly higher in patient with lymphoma than in controls, especially when considering samples stored 0-2-year period before the lymphoma diagnosis. In the multivariable analysis, the elevation of sFLC predicted the risk of lymphoma independently of CD4 count, (odd ratio of 16.85 for k + λ sFLC >2-fold upper normal limit (UNL) vs. normal value). A significant reduction in the risk of lymphoma (odd ratio of 0.07 in model with k + λ sFLC) was found in people with low sFLC and undetectable HIV viremia lasting more than 6 months. Our analysis indicates that an elevated polyclonal sFLC is a strong and sensitive predictor of the risk of developing lymphomas, and it is an easy to measure biomarker that merits consideration for introduction in routine clinical practice in people with HIV.

Hepatitis C virus production requires apolipoprotein A-I and affects its association with nascent low-density lipoproteins.

BACKGROUND/AIMS: The life cycle of hepatitis C virus (HCV) is intimately linked to the lipid metabolism of the host. In particular, HCV exploits the metabolic machinery of the lipoproteins in several steps of its life cycle such as circulation in the bloodstream, cell attachment and entry, assembly and release of viral particles. However, the details of how HCV interacts with and influences the metabolism of the host lipoproteins are not well understood. A study was undertaken to investigate whether HCV directly affects the protein composition of host circulating lipoproteins. METHODS: A proteomic analysis of circulating very low-, low- and high-density lipoproteins (VLDL, LDL and HDL), isolated from either in-treatment naïve HCV-infected patients or healthy donors (HD), was performed using two-dimensional gel electrophoresis and tandem mass spectrometry (MALDI-TOF/TOF). The results obtained were further investigated using in vitro models of HCV infection and replication. RESULTS: A decreased level of apolipoprotein A-I (apoA-I) was found in the LDL fractions of HCV-infected patients. This result was confirmed by western blot and ELISA analysis. HCV cellular models (JFH1 HCV cell culture system (HCVcc) and HCV subgenomic replicons) showed that the decreased apoA-I/LDL association originates from hepatic biogenesis rather than lipoprotein catabolism occurring in the circulation, and is not due to a downregulation of the apoA-I protein concentration. The sole non-structural viral proteins were sufficient to impair the apoA-I/LDL association. Functional evidence was obtained for involvement of apoA-I in the viral life cycle such as RNA replication and virion production. The specific siRNA-mediated downregulation of apoA-I led to a reduction in both HCV RNA and viral particle levels in culture. CONCLUSIONS: This study shows that HCV induces lipoprotein structural modification and that its replication and production are linked to the host lipoprotein metabolism, suggesting apoA-I as a new possible target for antiviral therapy.

25-Hydroxyvitamin D Plasma Levels in Natural Populations of Pigmented and Partially Pigmented Land Iguanas from Galápagos (Conolophus spp.).

We report the first data on 25-hydroxyvitamin D plasma levels in natural populations of three species of land iguana endemic to the Galápagos Islands (Conolophus marthae, C. subcristatus, and C. pallidus). The pigment is present throughout the whole body in the skin of C. subcristatus and C. pallidus. On the contrary, pigment is not present in the skin of an extended part of the body in C. marthae. The only existing population of C. marthae is syntopic with a population of C. subcristatus, and the two species are closely related. These circumstances would suggest that, under the assumption that the species show a similar basking behavior and in the absence of compensatory mechanisms, lighter pigmentation should favor higher vitamin D levels. Thus, C. marthae, compared with C. subcristatus in Wolf Volcano, could show higher levels of 25(OH)D plasma levels, or equal, if compensatory mechanisms exist. The three species showed levels in the range of average values for healthy iguanas. However, contrary to the expectation, C. marthae consistently exhibited the lowest 25(OH)D plasma levels. We discuss possible factors affecting vitamin concentration and hypothesize that C. marthae may use the habitat to limit exposure to the high UVB irradiation at Wolf Volcano.

Vertical transmission of HCV infection: prospective study in infants born to HIV-1 seronegative women.

OBJECTIVE: We performed a long-term prospective trial in infants born to HCV positive but HIV-1 negative women, with the aim of evaluating vertical transmission of HCV and correlated risks factors. METHODS: From April 1996 to May 2002, 50 women in the 3rd trimester of pregnancy or close to delivery we enrolled in the study. Anti-HCV antibodies were detected by 2nd and 3rd generation ELISA tests (ABBOTT HCV 2nd EIA generation and MEIA Abbot Labs, IL) . Reactivity was confirmed by a commercial immunoblot (Abbott Matrix HCV 2.0) ad HCV-RNA was detected by a nested-PCR technique. Infants were prospectively followed by clinical and laboratory tests (ALT levels, anti HCV Ab and HCV RNA) every 3 or 6 months for 16 to-80 months (average: 28.5 months). RESULTS: Twenty-eight of 50 women (56%) were found positive for HCV-RNA at delivery, and in 17/50 no risk factors for HCV infection were identified. Vertical transmission of HCV was detected in 3/28 infants born to viremic mothers (10.7%), while none of the 22 non-viremic mothers transmitted the infection to their children. Prolonged HCV seronegativity was documented in one of the three infected infants. During follow-up three other infants presented a single positive PCR value; one infant resulted HCV positive at 51 months of age. All infants were anti-HCV positive at delivery due to passive acquisition of antibodies, and in the 44 uninfected infants the antibody titres decreased progressively and became negative at various intervals (3-18 months). CONCLUSION: The overall vertical transmission rate was 6% but the risk of transmission of HCV infection is limited to women that are HCV RNA positive at delivery. This study shows that vertical transmission of HCV infection possibly occurs in immunocompetent infants with no HCV antibodies detected in the serum. Furthermore, we emphasise that a prolonged follow-up is absolutely mandatory in order ot establish the occurrence of active infection.

High urine IP-10 levels associate with chronic HCV infection.

OBJECTIVES: Independent of IL-28B polymorphisms, blood IP-10 is a promising biomarker for predicting therapy response in chronic HCV infection. Urine IP-10 has been proposed as a biomarker in tuberculosis, but to date, no urine biomarkers for HCV infection have been evaluated. In this cross-sectional study, we assessed whether IP-10 is detectable in the urine of chronically HCV-infected patients, and if so, whether urine IP-10 correlates with serum IP-10 and HCV-specific clinical parameters. METHODS: IP-10 was measured by ELISA in serum and urine concomitantly taken from 38 HCV-viremic patients, 10 cured-HCV subjects and 11 healthy donors enrolled as controls. RESULTS: The urine of HCV-viremic patients showed measurable amounts of IP-10, although significantly lower than in serum (p < 0.0001). Urine IP-10 was normalized with creatinuria levels and we found that the urine IP-10/creatinuria ratio was significantly higher in HCV-viremic patients than in cured-HCV subjects (p = 0.002) and healthy donors (p = 0.008), and that it significantly correlated with transaminases (p = 0.01), although the correlation was low. Similarly, the serum IP-10 level significantly associated with HCV-viremic patients (p < 0.0001) and correlated with transaminases (p < 0.0001). CONCLUSIONS: For the first time to our knowledge, we show that IP-10 is detected and increased in the urine of HCV-viremic patients compared to healthy donors and cured-HCV subjects.