Nonlytic viral spread enhanced by autophagy components

Significance The cell-to-cell spread of viruses that are not surrounded by membranes was thought to occur only by destruction of the infected cell, as no obvious path for a cytoplasmic particle to penetrate the plasma membrane exists. Nonetheless, it is known that spread within tissues in human infections is not always accompanied by obvious cell death. Here we use quantitative single-cell analysis to show that poliovirus can spread to a neighboring cell prior to bursting and killing the originally infected cell. This type of spread is dependent on components of the autophagy pathway, a recycling pathway that is found in all eukaryotes. This finding identifies targets to block the spread of viruses and other toxic cytoplasmic assemblages.