Anti-HCV Core Protein Monoclonal antibody, Clone 3G7[Biotin]

Background A few cases of hepatitis B virus (HBV) reactivation during anti-viral therapy against hepatitis C (HCV) have been reported. However, the information regarding the real impact of this phenomenon is scarce. Aim To evaluate the risk of HBV reactivation during anti-viral therapy against HCV with an interferon-free regimen with direct-acting anti-virals (DAAs). Methods Observational and prospective study of 352 patients receiving DAAs therapy between September 2015 and May 2016. HBV-DNA and ALT levels were monitored at baseline, at week 4 of anti-viral therapy, at end of treatment and 12 weeks after treatment discontinuation in patients with HBV surface antigen (HBsAg) positive or HBV core antibody (anti-HBc) positive before starting anti-viral therapy. Results Ten (2.8%) and 64 (18%) patients were HBsAg and anti-HBc positive at baseline, respectively. Five (50%) of 10 HBsAg positive and one (1.6%) of 64 anti-HBc positive patients presented HBV virological reactivation (>1log increase in HBV-DNA levels). None of these patients presented clinical reactivation (increase in ALT levels). Conclusions HBV virological reactivation is frequent in HBsAg+ patients receiving anti-viral therapy against HCV. However, HBV-DNA elevations were modest (<20 000 IU/mL) and without clinical impact (no ALT elevation).

Background: Hepatitis C virus (HCV) is major cause of liver cirrhosis in humans. HCV capsid (core) protein (HCVcp) is a highly demanded antigen for various diagnostic, immunization and pathogenesis studies. Plants are considered as an expression system for producing safe and inexpensive biopharmaceutical proteins. Although invention of transgenic (stable) tobacco plants expressing HCVcp with proper antigenic properties was recently reported, no data for "transient-expression" that is currently the method of choice for rapid, simple and lower-priced protein expression in plants is available for HCVcp. Objectives: The purpose of this study was to design a highly codon-optimized HCVcp gene for construction of an efficient transient-plant expression system for production of HCVcp with proper antigenic properties in a regional tobacco plant (Iranian jafarabadi-cultivar) by evaluation of different classes of vectors and suppression of gene-silencing in tobacco. Materials and Methods: A codon-optimized gene encoding the Kozak sequence, 6xHis-tag, HCVcp (1-122) and KDEL peptide in tandem (from N- to C-terminal) was designed and inserted into potato virus-X ( PVX) and classic pBI121 binary vectors in separate cloning reactions. The resulted recombinant plasmids were transferred into Agrobacterium tumefaciens and vacuum infiltrated into tobacco leaves. The effect of gene silencing suppressor Pig protein derived from tomato bushy stunt virus on the expression yield of HCVcp by each construct was also evaluated by co-infiltration in separate groups. The expressed HCVcp was evaluated by dot and western blotting and ELISA assays. Results: The codon-optimized gene had an increased adaptation index value (from 0.65 to 0.85) and reduced GC content (from 62.62 to 51.05) in tobacco and removed the possible deleterious effect of "GGTAAG" splice site in native HCVcp. Blotting assays via specific antibodies confirmed the expression of the 15 kDa HCVcp. The expression level of HCVcp was enhanced by 4-5 times in Pig co-agroinfiltrated plants with better outcomes for PVX, compared to pBI121 vector (0.022% versus 0.019% of the total soluble protein). The plant-derived HCVcp (pHCVcp) could properly identify the HCVcp antibody in HCV-infected human sera compared to Escherichio coli-derived HCVcp (eHCVcp), indicating its potential for diagnostic/immunization applications. Conclusions: By employment of gene optimization strategies, use of viral-based vectors and suppression of plant-derived gene silencing effect, efficient transient expression of HCVcp in tobacco with proper antigenic properties could be possible.