Our Cells Unwittingly Support Viral Entry and Infection

Human adenoviruses comprise 25% of all gene therapy clinical trials due, in part, to their ability to infect both dividing and nondividing cells with persistent expression. Recently, researchers at the University of Zurich demonstrated how these viruses gain entry into our cells — and it’s quite sneaky!

Gaining entry into cells is a key step in the viral infection process. Once the viruses are in our cells, they are able to use the host cell machinery to replicate. Now, it turns out, certain viruses like the human adenovirus are able to use our response to cellular damage to trigger an infection. Adenoviruses damage the external cell membrane by causing small pores in it. Though these pores are too small for the virus to use to gain entry into our cells, they are sufficient to elicit a cellular response for damage repair. The repair process involves the formation of certain types of lipids, called ceramide lipids, which cause the formation of endosomes. Endosomes have the ability to engulf extracellular materials, and in this case, they internalize the adenovirus on the cell surface.

The scientists in this study also identified a potential adenovirus inhibitor. The inhibitor suppresses the cellular lysosomal acid sphingomyelinase protein, blocking the formation of ceramide lipids. Further research into the impact of this inhibitor and its role as an anti-viral agent is ongoing.

Source: University of Zurich