Structure and Function of the Human Respiratory Syncytial Virus M2–1 Protein

Human respiratory syncytial virus (HRSV) is a non-segmented negative stranded RNA virus and is recognized as the most important viral agent of lower respiratory tract infection worldwide, responsible for up to 199,000 deaths each year. The only FDA-approved regime to prevent HRSV-mediated disease is pre-exposure administration of a humanized HRSV-specific monoclonal antibody, which although being effective, is not in widespread usage due to its cost. No HRSV vaccine exists and so there remains a strong need for alternative and complementary anti-HRSV therapies. The HRSV M2–1 protein is a transcription factor and represents an attractive target for the development of antiviral compounds, based on its essential role in the viral replication cycle. To this end, a detailed analysis of M2–1 structure and functions will aid in identifying rational targets for structure-based antiviral drug design that can be developed in future translational research. Here we present an overview of the current understanding of the structure and function of HRSV M2–1, drawing on additional information derived from its structural homologues from other related viruses

Significance and Management of Isolated Hepatitis B Core Antibody (Anti-HBc) in HIV and HCV: Strategies in the DAA Era

PURPOSE OF REVIEW:The purpose of this review is to summarize the prevalence and clinical implications of the isolated anti-HBc serologic profile in HIV-infected individuals. We highlight the rare but important issue of HBV reactivation in the setting of HCV therapy and describe an approach to management. RECENT FINDINGS:The isolated anti-HBc pattern, a profile that most often indicates past exposure to HBV with waning anti-HBs immunity, is found commonly in HIV-infected individuals, particularly those with HCV. Some large cohort studies demonstrate an association with advanced liver disease, while others do not. Conversely, meta-analyses have found an association between occult HBV infection (a component of the isolated anti-HBc pattern) and advanced liver disease and hepatocellular carcinoma in HIV-uninfected individuals. In HIV-uninfected individuals with anti-HBc positivity, HBV reactivation has been reported in patients receiving HCV therapy. This phenomenon is likely the result of disinhibition of HBV with HCV eradication. In HIV-infected patients, the long-term liver outcomes associated with the isolated anti-HBc pattern remain to be fully elucidated, supporting the need for large cohort studies with longitudinal follow-up. HBV reactivation during HCV DAA therapy has been well-described in HIV-uninfected cohorts and can inform algorithms for the screening and management of the isolated anti-HBc pattern in this population