Host enzymes activate influenza D virus

What is it about?

This paper is about how influenza D virus gets “switched on” so it can infect cells. The virus needs host enzymes called serine proteases to cut its surface protein HEF into an active form, and the study shows that human airway trypsin-like protease (HAT) and the swine version of that enzyme can do this well, while TMPRSS2 does not work well for influenza D HEF.

Featured Image

Photo by mana5280 on Unsplash

Photo by mana5280 on Unsplash

Why is it important?

This paper is important because it identifies the host enzymes that turn influenza D virus into an infectious form, which fills an important gap in how this virus works. Knowing the activation step helps explain where the virus can grow, which animals or tissues it may use, and what may control its spread. It is also useful for risk assessment. We found that human and swine airway proteases can activate influenza D virus, and we suggest that protease specificity is probably not what blocks the virus from infecting the human upper respiratory tract. That means researchers should look at other barriers, such as receptors or immune factors, when judging whether influenza D could become a human health concern. There is a practical angle too: host proteases can be potential drug targets, so this kind of work can point toward new ways to block infection without directly targeting the virus.

Perspectives