Hemorrhagic fevers caused by members of the filovirus family have high fatality rates but remain poorly understood. Scientists suspect that these viruses enter the human population through zoonotic spillover events, but only one, Marburg virus, has been identified in the Egyptian fruit bat, Rousettus aegyptiacus. Although studying bat-derived viruses offers glimpses into how these entities survive in their original host and how these may first emerge in humans, most research still uses human isolates.
Joseph Prescott, an immunologist and virologist at the Robert Koch Institute, studies Marburg virus infection in Egyptian fruit bats and the animal’s immune response to it. “The end goal is trying to compare what’s happening in the natural reservoir… to what’s happening in humans,” he explained. In a recent paper published in npj Viruses, he and his team explored human macrophage activity against a bat-isolated Marburg virus and found distinct responses between individuals.
“These are critical questions to better understand what happens,” said Gaya Amarasinghe, a virologist at Washington University who studies host pathogen interactions in RNA viruses. “What drives the species crossing? And more importantly, what are the adaptations and what happens in different species?”
Prescott and his team isolated monocytes from blood donors and cultured them into macrophages, which were then infected with bat-derived Marburg virus that expressed a fluorescent reporter. “[Bat-derived Marburg virus] would, presumably be what’s initially infecting a human. And then we know that macrophages and dendritic cells are some of the initial target cells, so we’re trying to model the spillover,” he said.
While the virus infected macrophages from all donors, its efficiency in doing so ranged from 10-80 percent of the cell population. To explore this further, the team investigated the changes in gene expression by RNA sequencing cells of five donors after Marburg virus infection or stimulation with lipopolysaccharide (LPS), a potent macrophage activator.
By Shelby Bradford, PhD
Article can be accessed on: The Scientist