A Sensitive in Vitro High-Throughput Screen To Identify Pan-filoviral Replication Inhibitors Targeting the VP35-NP Interface.

The 2014 Ebola outbreak in West Africa, the largest outbreak on record, highlighted the need for novel approaches to therapeutics targeting Ebola virus (EBOV). Within the EBOV replication complex, the interaction between polymerase cofactor, viral protein 35 (VP35), and nucleoprotein (NP) is critical for viral RNA synthesis. We recently identified a peptide at the N-terminus of VP35 (termed NPBP) that is sufficient for interaction with NP and suppresses EBOV replication, suggesting that the NPBP binding pocket can serve as a potential drug target. Here we describe the development and validation of a sensitive high-throughput screen (HTS) using a fluorescence polarization assay. Initial hits from this HTS include the FDA-approved compound tolcapone, whose potency against EBOV infection was validated in a nonfluorescent secondary assay. High conservation of the NP-VP35 interface among filoviruses suggests that this assay has the capacity to identify pan-filoviral inhibitors for development as antivirals.

New small molecule entry inhibitors targeting hemagglutinin-mediated influenza a virus fusion.

Influenza viruses are a major public health threat worldwide, and options for antiviral therapy are limited by the emergence of drug-resistant virus strains. The influenza virus glycoprotein hemagglutinin (HA) plays critical roles in the early stage of virus infection, including receptor binding and membrane fusion, making it a potential target for the development of anti-influenza drugs. Using pseudotype virus-based high-throughput screens, we have identified several new small molecules capable of inhibiting influenza virus entry. We prioritized two novel inhibitors, MBX2329 and MBX2546, with aminoalkyl phenol ether and sulfonamide scaffolds, respectively, that specifically inhibit HA-mediated viral entry. The two compounds (i) are potent (50% inhibitory concentration [IC50] of 0.3 to 5.9 µM); (ii) are selective (50% cytotoxicity concentration [CC(50)] of >100 µM), with selectivity index (SI) values of >20 to 200 for different influenza virus strains; (iii) inhibit a wide spectrum of influenza A viruses, which includes the 2009 pandemic influenza virus A/H1N1/2009, highly pathogenic avian influenza (HPAI) virus A/H5N1, and oseltamivir-resistant A/H1N1 strains; (iv) exhibit large volumes of synergy with oseltamivir (36 and 331 µM(2) % at 95% confidence); and (v) have chemically tractable structures. Mechanism-of-action studies suggest that both MBX2329 and MBX2546 bind to HA in a nonoverlapping manner. Additional results from HA-mediated hemolysis of chicken red blood cells (cRBCs), competition assays with monoclonal antibody (MAb) C179, and mutational analysis suggest that the compounds bind in the stem region of the HA trimer and inhibit HA-mediated fusion. Therefore, MBX2329 and MBX2546 represent new starting points for chemical optimization and have the potential to provide valuable future therapeutic options and research tools to study the HA-mediated entry process.

Effect of psoriatic arthritis according to the affected categories of the international classification of functioning, disability and health.

OBJECTIVE: To determine the categories of the International Classification of Functioning, Disability and Health (ICF) checklist and core sets of rheumatoid arthritis and ankylosing spondylitis frequently occurring in people with psoriatic arthritis (PsA) and to compare the number of such categories with scores on self-report measures of participation restrictions and activity limitations. METHODS: Data were collected from 94 patients with PsA attending rheumatology clinics in 6 centers. For each ICF category affected by PsA in at least 30% of patients, the percentage of such patients was determined for Body Structures, Body Functions, Activities and Participation, and Environmental Factors. A count of all affected categories by ICF chapter was compared to patient self-report scores on a number of functional and health status instruments using Spearman's correlation. RESULTS: There were 25 categories in the Body Functions section, 6 categories in the Body Structures section, and 51 categories in the Activities and Participation section that were relevant in at least 30% of participants. Thirteen Environmental Factors were facilitating and 1 Environmental Factor (climate) was a barrier in at least 30% of participants. The number of involved Activities and Participation categories by chapter did not correlate in predictable ways with self-report measures of participation restrictions and activity limitations. CONCLUSION: PsA is associated with a wide range of impairments, limitations, and restrictions across the ICF categories. People with PsA find environmental factors to be helpful more often than to be barriers. The unexpected pattern of correlation between ICF chapters and self-report measures suggests the need for a better way of quantitatively representing the ICF concepts.