Hepatitis C Virus E2 Protein Ectodomain Is Essential for Assembly of Infectious Virions

The Hepatitis C virus E1 and E2 envelope proteins are the major players in all events required for virus entry into target cells. In addition, the recently developed HCV cell culture system has indicated that E1E2 heterodimer formation is a prerequisite for viral particle production. In this paper, we explored a new genetic approach to construct intergenotypic 2a/1b chimeras, maintaining the structural region of the infectious strain JFH1 and substituting the soluble portion of E1 and/or E2 proteins. This strategy provides useful information on the role of the surface-exposed domain of the envelope proteins in virus morphogenesis and allows comparative analysis of different HCV genotypes. We found that substituting the E2 protein ectodomain region abolishes the production of chimeric infectious particles. Our data indicate that the soluble part of the E2 protein is involved in a genotype-specific interplay with remaining viral proteins that affect the HCV assembly process

Calcitonin Gene-Related Peptide (CGRP)-Targeted Treatments—New Therapeutic Technologies for Migraine

Migraine is ranked as the third most common disorder worldwide and is considered one of the most disabling neurological conditions. Its treatment has mostly relied on medications that were non-specifically developed for migraine, thus accompanied by low adherence, inadequate effectiveness and intolerable side effects. These recent years have seen the development of new migraine-specific therapies targeting the calcitonin gene-related peptide (CGRP) and its receptor. These newly developed therapies, the small molecule gepants targeting the CGRP receptor and the anti-CGRP monoclonal antibodies (mAbs), are currently available in the market and FDA-approved for migraine treatment. As they are migraine-specific therapies, they largely expand their use to patients that could not tolerate previous treatments, either for systemic contraindications or drug-to-drug interactions, or where any other available option was not efficacious. Randomized controlled trials have demonstrated the efficacy of these new medications, with minor adverse effects reported (most commonly nausea and constipation). This article will review the mechanism of action, indications, contraindications, and tolerability profile of gepants and anti-CGRP mAbs, by summarizing the available literature. Finally, avenues for future research will be identified, so that upcoming controlled studies may be designed to fill such gaps

Intracellular accumulation of hepatitis C virus proteins in a human hepatoma cell line

Background/Aims: The establishment of HCV replicon systems strongly improved the research on the replication processes but poorly advanced our knowledge on the subcellular localization of the structural glycoproteins, mainly due to their low expression. We sought to verify whether reinforcing E1E2 expression in the context of both HCV genomic and subgenomic replicon from either homologous or heterologous strains leads to formation of supramolecular structures including structural and nonstructural proteins. Methods:Robust expression ofHCV glycoproteins was achieved by stable expression of E1E2p7 from genotype 1a and 1b. Results: In these cells, E1 and E2 triggered the formation of dot-like structures in which they co-localized with core and the nonstructural proteins NS3 and NS5A. Confocal microscopy analyses suggested that accumulation of HCV proteins occurs in an ER-derived subcompartment. Moreover, by labeling de novo-synthesized HCV RNA, we showed that these structures constitute a site of viral RNA synthesis. Conclusions: Expression in trans of HCV glycoproteins in the context of replicative viral genome or subgenome generates accumulation of structural and nonstructural viral proteins in peculiar cytoplasmic structures. The simultaneous presence of viral RNA, structural and nonstructural protein suggests that these complexes represent not only sites of HCV replication but also potential places of viral pre-budding

CD81 Is a Central Regulator of Cellular Events Required for Hepatitis C Virus Infection of Human Hepatocytes▿ †

Infection with hepatitis C virus (HCV) is still a major public health problem, and the events leading to hepatocyte infection are not yet fully understood. Combining confocal microscopy with biochemical analysis and studies of infection requirements using pharmacological inhibitors and small interfering RNAs, we show here that engagement of CD81 activates the Rho GTPase family members Rac, Rho, and Cdc42 and that the block of these signaling pathways drastically reduces HCV infectivity. Activation of Rho GTPases mediates actin-dependent relocalization of the HCV E2/CD81 complex to cell-cell contact areas where CD81 comes into contact with the tight-junction proteins occludin, ZO-1, and claudin-1, which was recently described as an HCV coreceptor. Finally, we show that CD81 engagement activates the Raf/MEK/ERK signaling cascade and that this pathway affects postentry events of the virus life cycle. In conclusion, we describe a range of cellular events that are manipulated by HCV to coordinate interactions with its multiple coreceptors and to establish productive infections and find that CD81 is a central regulator of these events

A multi-element psychosocial intervention for early psychosis (GET UP PIANO TRIAL) conducted in a catchment area of 10 million inhabitants: study protocol for a pragmatic cluster randomized controlled trial

Multi-element interventions for first-episode psychosis (FEP) are promising, but have mostly been conducted in non-epidemiologically representative samples, thereby raising the risk of underestimating the complexities involved in treating FEP in 'real-world' services