Calcium Ions Directly Interact with the Ebola Virus Fusion Peptide To Promote Structure-Function Changes That Enhance Infection.

Ebola virus disease is a serious global health concern given its periodic occurrence, high lethality, and the lack of approved therapeutics. Certain drugs that alter intracellular calcium, particularly in endolysosomes, have been shown to inhibit Ebola virus infection; however, the underlying mechanism is unknown. Here, we provide evidence that (EBOV) infection is promoted in the presence of calcium as a result of the direct interaction of calcium with the EBOV fusion peptide (FP).

Single Virion Tracking Microscopy for the Study of Virus Entry Processes in Live Cells and Biomimetic Platforms.

The most widely-used assays for studying viral entry, including infectivity, cofloatation, and cell-cell fusion assays, yield functional information but provide low resolution of individual entry steps. Structural characterization provides high-resolution conformational information, but on its own is unable to address the functional significance of these conformations. Single virion tracking microscopy techniques provide more detail on the intermediate entry steps than infection assays and more functional information than structural methods, bridging the gap between these methods.

Production of Pseudotyped Particles to Study Highly Pathogenic Coronaviruses in a Biosafety Level 2 Setting.

The protocol aims to generate coronavirus (CoV) spike (S) fusion protein pseudotyped particles with a murine leukemia virus (MLV) core and luciferase reporter, using a simple transfection procedure of the widely available HEK-293T cell line. Once formed and released from producer cells, these pseudovirions incorporate a luciferase reporter gene. Since they only contain the heterologous coronavirus spike protein on their surface, the particles behave like their native coronavirus counterparts for entry steps.