High-Dose Mannose-Binding Lectin Therapy for Ebola Virus Infection

Mannose-binding lectin (MBL) targets diverse microorganisms for phagocytosis and complement-mediated lysis by binding specific surface glycans. Although recombinant human MBL (rhMBL) trials have focused on reconstitution therapy, safety studies have identified no barriers to its use at higher levels. Ebola viruses cause fatal hemorrhagic fevers for which no treatment exists and that are feared as potential biothreat agents. We found that mice whose rhMBL serum concentrations were increased ≥7-fold above average human levels survived otherwise fatal Ebola virus infections and became immune to virus rechallenge. Because Ebola glycoproteins potentially model other glycosylated viruses, rhMBL may offer a novel broad-spectrum antiviral approach

Venezuelan Equine Encephalitis Virus Replicon Particle Vaccine Protects Nonhuman Primates from Intramuscular and Aerosol Challenge with Ebolavirus

There are no vaccines or therapeutics currently approved for the prevention or treatment of ebolavirus infection. Previously, a replicon vaccine based on Venezuelan equine encephalitis virus (VEEV) demonstrated protective efficacy against Marburg virus in nonhuman primates. Here, we report the protective efficacy of Sudan virus (SUDV)- and Ebola virus (EBOV)-specific VEEV replicon particle (VRP) vaccines in nonhuman primates. VRP vaccines were developed to express the glycoprotein (GP) of either SUDV or EBOV. A single intramuscular vaccination of cynomolgus macaques with VRP expressing SUDV GP provided complete protection against intramuscular challenge with SUDV. Vaccination against SUDV and subsequent survival of SUDV challenge did not fully protect cynomolgus macaques against intramuscular EBOV back-challenge. However, a single simultaneous intramuscular vaccination with VRP expressing SUDV GP combined with VRP expressing EBOV GP did provide complete protection against intramuscular challenge with either SUDV or EBOV in cynomolgus macaques. Finally, intramuscular vaccination with VRP expressing SUDV GP completely protected cynomolgus macaques when challenged with aerosolized SUDV, although complete protection against aerosol challenge required two vaccinations with this vaccine

Synthesis and Structure-Activity Relationships of 3,5-Disubstituted-pyrrolo[2,3-b]pyridines as Inhibitors of Adaptor-Associated Kinase 1 with Antiviral Activity

There are currently no approved drugs for the treatment of emerging viral infections, such as dengue and Ebola. Adaptor-associated kinase 1 (AAK1) is a cellular serine-threonine protein kinase that functions as a key regulator of the clathrin-associated host adaptor proteins and regulates the intracellular trafficking of multiple unrelated RNA viruses. Moreover, AAK1 is overexpressed specifically in dengue virus-infected but not bystander cells. Because AAK1 is a promising antiviral drug target, we have embarked on an optimization campaign of a previously identified 7-azaindole analogue, yielding novel pyrrolo[2,3- b]pyridines with high AAK1 affinity. The optimized compounds demonstrate improved activity against dengue virus both in vitro and in human primary dendritic cells and the unrelated Ebola virus. These findings demonstrate that targeting cellular AAK1 may represent a promising broad-spectrum antiviral strategy.status: publishe

Genetic inactivation of Orai Ca²⁺ permeation inhibits egress of authentic filoviruses and arenaviruses.

<p>Wild type HEK293T cells and a Ca²⁺ permeation defective HEK293T line that stably overexpresses the dominant negative Orai E106A mutant were infected with LASV (MOI 0.05), JUNV (MOI 0.1), MARV (MOI 0.1), or EBOV (MOI 0.5). Cellular virus levels were detected by immunofluorescence staining of fixed cells at 72 (LASV) or 96 (JUNV, MARV, EBOV) hours post infection. The percent of infected cells relative to total viable cells per condition is plotted and error bars represent standard error of mean (SEM). Statistical significance was determined by student t test, two-tailed (*** p < 0.0001, **** p < 0.0001 as indicated)</p

Budding of filovirus and arenavirus VLPs from WT and E106A cells.

<p>WT or Orai1 E106A mutant HEK293T cells were transfected as indicated with eVP40 <b>(A)</b>, mVP40 <b>(B)</b>, JUNV-Z <b>(C)</b>, or LASV-Z <b>(D)</b> for 24 hours and VP40 or Z protein levels in cells and VLPs were quantified by immunoblot analysis. Expression of cellular actin served as a loading control. Results are representative of three independent experiments.</p

Synta66 inhibits egress of authentic filoviruses and arenaviruses.

<p><b>A</b>. HeLa cells were infected with LASV (MOI 0.01), JUNV (MOI 0.1), MARV (MOI 0.1), or EBOV (MOI 0.1) and treated with Synta66 at indicated concentrations. Cellular virus levels were detected by immunofluorescence staining of fixed cells at 72 (LASV, JUNV) or 96 (MARV, EBOV) hours post infection with virus specific antibodies. The percent of cells infected (relative to total cells) was determined using Harmony High Content Imaging and Analysis software (PerkinElmer). Data is expressed relative to vehicle (DMSO) control treated cells for each virus. The percent of infected cells for vehicle control treatment was as follows (LASV = 12% ± 2.69%, JUNV = 9% ± 1.11%, MARV = 20% ± 1.92%, EBOV = 15% ± 1.55%). Error bars indicate standard error of mean (SEM) and statistical significance was determined by two way ANOVA with Bonferroni multiple comparisons (** p < 0.01, **** p < 0.0001). <b>B</b>. Representative images from a single live virus experiment demonstrate Synta66 dose (0, 5, 10, 30, 50μM) dependent inhibition of virus spread. For each condition, respective viruses were detected with virus specific antibodies (green). The value in the upper left hand corner of each image is the percentage of total cells infected. For each condition, the total number of cells was determined by staining nuclear DNA with Hoechst DNA dye.</p