How our cells can 'swallow up and quarantine' Zika

How our cells can 'swallow up and quarantine' Zika

Researchers have shown that a very small protein we all have in our bodies, interferon-induced protein 3 (IFITM3), can dramatically reduce the ability of Zika virus to infect human and mouse cells. In some cases, IFITM3 can also prevent Zika virus from killing our cells. The findings suggest that boosting the actions of IFITM3 may be useful for inhibiting Zika virus and other emerging viral infections. The study appears in the journal Cell Reports.

There is no treatment for Zika virus infection. The best way to prevent the infection is to limit potential exposure to the infected mosquitos that carry the disease. As summer heats up and mosquito season gets under way, the World Health Organization expects the virus to spread throughout much of the Americas including parts of the United States.

From their earlier research on dengue virus and other flaviviruses related to Zika virus, the group had a hunch that IFITM3 might reduce or block viral infection. Using the IFITM3 tools and assays they'd developed for studying dengue and influenza viruses, the lab was able to rapidly test IFITM3's effect on Zika virus.

Found in nearly all human cells, IFITM3 works to alter the cell membrane, making it more difficult for viruses to penetrate this outer defense. The Brass lab found that when IFITM3 levels are low, Zika virus can more readily infiltrate into the cell interior and cause infection. Conversely, they discovered that when IFITM3 is abundant and on guard, it strongly prevents Zika virus from reaching the interior of the cell and so blocks its infection.

"In effect, we see that IFITM3 allows our cells to swallow up and quarantine the virus thereby stopping their own infection, and also the infection of neighboring cells" said George Savidis, a research associate in the Brass lab and the first author of the study. "We think this also reduces the levels of cell death caused by Zika virus.

"This work shows that IFITM3 acts as an early front line defender to prevent Zika virus from getting its hands on all of the resources in our cells that it needs to grow," said Savidis. "IFITM3 pretty much keeps Zika virus stuck in no man's land where it can't do anything to harm us."