Development of monoclonal antibody-based assays for the detection of Vibrio tubiashii zinc-metalloprotease (VtpA)

Vibrio tubiashii has been linked to disease outbreaks in molluscan species, including oysters, geoducks, and clams. In particular, oyster hatcheries in the Pacific Northwest have been plagued by intermittent vibriosis since 2006. Accurate detection of vibrios, including V. tubiashii, is critical to the hatcheries in order to allow for rapid remediation efforts. The current methods for detection of Vibrio spp. are not ideal for use at the hatchery. Plating samples require time and is not sensitive to extracelluar pathogenic products, such as the secreted zinc-metalloprotease, VtpA. Other sensitive methods to detect bacteria, such as qPCR, require a high level of laboratory skills and expensive supplies that are prohibitive for use at hatchery sites. Thus, hatcheries would benefit from a sensitive, simple method to detect V. tubiashii and its secreted toxin. Here, we describe the development of two inexpensive and highly specific tests for the shellfish—toxic zinc-metalloprotease secreted by V. tubiashii: enzyme-linked immunoassays (ELISA) and a lateral flow immunoassay (dipstick assay). Both technologies rely on a set of monoclonal antibodies used in a sandwich format, with the capture antibody recognizing a different epitope than the detection antibody on the mature VtpA protein. Both assays are quantitative and give colorimetric readouts. The sandwich ELISA was sensitive when VtpA was diluted into PBS, but was markedly less sensitive in conditions that correlate with the environment of hatchery-derived samples, such as in the presence of seawater, algae, or oyster larvae. In contrast, the dipstick assay remained very sensitive in the presence of these contaminants, is less work-intensive, and much more rapid, making this format the preferred assay method for detecting VtpA on site in a hatchery or environmental setting.This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain

Supplementary data for the article: Selaković, Z.; Soloveva, V.; Gharaibeh, D. N.; Wells, J.; Šegan, S.; Panchal, R. G.; Šolaja, B. A. Anti-Ebola Activity of Diazachrysene Small Molecules. ACS Infectious Diseases 2016, 1 (6), 264–271. https://doi.org/10.1021/acsinfecdis.5b00028

Supporting information for: [https://doi.org/10.1021/acsinfecdis.5b00028]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2035

Supplementary data for the article: Selaković, Z.; Soloveva, V.; Gharaibeh, D. N.; Wells, J.; Šegan, S.; Panchal, R. G.; Šolaja, B. A. Anti-Ebola Activity of Diazachrysene Small Molecules. ACS Infectious Diseases 2016, 1 (6), 264–271. https://doi.org/10.1021/acsinfecdis.5b00028

Supporting information for: [https://doi.org/10.1021/acsinfecdis.5b00028]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2035

Anti-Ebola Activity of Diazachrysene Small Molecules

Herein we report on a diazachrysene class of small molecules that exhibit potent antiviral activity against the Ebola (EBOV) virus. The antiviral compounds are easily synthesized, and the most active compounds have excellent in vitro activity (0.34–0.70 μM) and are significantly less lipophilic than their predecessors. The three most potent diazachrysene antivirals do not exhibit any toxicity in vivo and protected 70–90% of the mice at 10 mg/kg following EBOV challenge. Together, these studies suggest that diazachrysenes are a promising class of compounds for hit to lead optimization and as potential Ebola therapeutics

A Potent Lassa Virus Antiviral Targets an Arenavirus Virulence Determinant

Arenaviruses are a significant cause of hemorrhagic fever, an often-fatal disease for which there is no approved antiviral therapy. Lassa fever in particular generates high morbidity and mortality in West Africa, where the disease is endemic, and a recent outbreak in Nigeria was larger and more geographically diverse than usual. We are developing LHF-535, a small-molecule viral entry inhibitor that targets the arenavirus envelope glycoprotein, as a therapeutic candidate for Lassa fever and other hemorrhagic fevers of arenavirus origin. Using a lentiviral pseudotype infectivity assay, we determined that LHF-535 had sub-nanomolar potency against the viral envelope glycoproteins from all Lassa virus lineages, with the exception of the glycoprotein from the LP strain from lineage I, which was 100-fold less sensitive than that of other strains. This reduced sensitivity was mediated by a unique amino acid substitution, V434I, in the transmembrane domain of the envelope glycoprotein GP2 subunit. This position corresponds to the attenuation determinant of Candid#1, a live-attenuated Junı´n virus vaccine strain used to prevent Argentine hemorrhagic fever. Using a virusyield reduction assay, we determined that LHF-535 potently inhibited Junı´n virus, but not Candid#1, and the Candid#1 attenuation determinant, F427I, regulated this difference in sensitivity. We also demonstrated that a daily oral dose of LHF-535 at 10 mg/kg protected mice from a lethal dose of Tacaribe virus. Serial passage of Tacaribe virus in LHF-535- treated Vero cells yielded viruses that were resistant to LHF-535, and the majority of drugresistant viruses exhibited attenuated pathogenesis. These findings provide a framework for the clinical development of LHF-535 as a broad-spectrum inhibitor of arenavirus entry and provide an important context for monitoring the emergence of drug-resistant viruses