Researchers have identified migrions, virus-like structures that enable faster and more severe viral spread by hijacking cell movement. These packages, formed in migrating cells infected with vesicular stomatitis virus, deliver multiple viral genomes simultaneously to new cells. The discovery challenges traditional models of infection and highlights increased disease potential in animal tests.
A team from Peking University Health Science Center and the Harbin Veterinary Research Institute has revealed a novel mechanism of viral transmission detailed in a study published in Science Bulletin. The research focuses on vesicular stomatitis virus (VSV), where infected cells pack viral genetic material and proteins into migrasomes—cellular structures that emerge during cell migration.
These migrasomes, containing viral nucleic acids and displaying the VSV surface protein VSV-G, form large virus-like entities dubbed "migrions." Unlike individual virus particles, migrions combine viral and cellular components, allowing for collective delivery. This bundling enables quicker replication in recipient cells, as multiple viral genomes arrive at once, initiating parallel infection processes.
Migrions stand out for their ability to transport more than one virus type simultaneously, differing from standard extracellular vesicle transmission. Upon reaching a new cell, they enter via endocytosis. Acidic conditions inside then activate VSV-G, prompting fusion with endosomes and release of viral contents to kickstart replication.
In mouse experiments, migrion-mediated infections proved far more potent than free virus exposure. Affected animals suffered severe lung and brain conditions, including encephalitis, often leading to fatal outcomes. This underscores the heightened pathogenicity of the migration-linked route.
The researchers describe migrions as a chimeric structure bridging viruses and migrasomes, introducing a migration-dependent transmission model. By exploiting the body's migratory systems, viruses can propagate more efficiently and systemically, potentially explaining rapid escalations in certain infections.
