Viruses infect filopodia

Curiosity may kill the cell, based on findings from Nathan Sherer, Walther Mothes (Yale University, New Haven, CT), and colleagues. The exploratory filopodia that cells send out can be caught by infected cells and used to spread viruses.

Mothes's group had already shown that viruses surf along the outer surface of filopodia toward the cell body. Now they find that infected fibroblasts deposit retroviral particles onto their neighbors' filopodia.

Infected cells grab filopodia using contacts between a transmembrane retroviral protein and its receptor in the uninfected cell. At the meeting point, the already infected cell tears off and takes in chunks of filopodial membrane by endocytosis. “The infected cell pulls the target cell into itself,” explains Mothes. “The forces must be gigantic.”...