National Heart, Lung, and Blood Institute (NHLBI)-funded researchers have discovered a novel means by which viruses spread between cells: multiple polioviruses, a type of enterovirus, travel together within a membrane-enclosed sac, arriving together at a cell they then infect. This finding revises a central tenet of virology that viruses behave as independent infectious agents. The discovery also suggests that this infection pathway may operate in other enteroviruses, which are responsible for a number of diseases, such as myocarditis (heart inflammation), the common cold, and the respiratory illness caused by Enterovirus D68.
Led by Dr. Nihal Altan-Bonnet, the Earl Stadtman Investigator in the NHLBI’s Laboratory of Host-Pathogen Dynamics, the team of NHLBI-funded researchers published their findings in the journal Cell.
In their article, the researchers describe the practical consequences of this infection pathway and suggest possible aspects of it that scientists could target to limit infections. By arriving at an uninfected cell together, the viruses infect the cell more efficiently than lone viruses. Moreover, once inside the cell, the viruses delivered all together are better able to survive and reproduce than viruses operating independently. After reproducing in the cell, multiple viral particles become enclosed by a membrane derived from the cell and exit the cell without bursting the cell. Although the membrane enclosing the viral particles likely protects them from detection by the body’s immune system, the researchers found that the membrane contains particular fat molecules that drugs can block. These drugs prevented the viral clusters from infecting cultured cells. Further study of the cellular components involved in loading up the viral cargo into the membrane-bound sacs may reveal other potential approaches to stopping viral transmission between cells.
A Q&A about the study can be found HERE.
Source: National Institutes of Health, the National Heart, Lung, and Blood Institute