Fighting Zika on a Cellular Level
Scientists have shown that a very small protein we have in our bodies can dramatically reduce the ability of the Zika virus to infect human and mouse cells, and in some cases can also prevent Zika from killing our cells.
The findings, about interferon-induced protein 3 (IFITM3), were published in the journal Cell Reports.
“This work represents the first look at how our cells defend themselves against Zika virus’ attack,” said senior author Abraham Brass, MD, PhD, assistant professor of microbiology and physiological systems. “Our results show that Zika virus has a weakness that we could potentially exploit to prevent or stop infection.”
Previous studies by Brass and Paul Kellam, PhD, a professor at the Wellcome Trust Sanger Institute in the UK, have shown that people who have a genetic variant, or allele, of the IFITM3 gene are more susceptible to the development of severe influenza. While relatively rare in people of European descent, this IFITM3 variant is more common in Asia and Micronesia. The current study suggests that it will be important to test whether this allele might contribute to the risk of more severe Zika virus infections and birth defects, according to Brass.
An expert in flaviviruses, a family of viruses transmitted by mosquitos that includes Zika, yellow fever, dengue and West Nile, Brass has developed a suite of genomic tools to probe how human cells respond to pathogens and how these invaders exploit host cell factors and proteins to replicate.
“Having these tools allowed us to respond quickly when the Zika virus threat emerged,” said Brass. “We simply adapted the technology we’d developed over the last four years working with dengue, influenza and other viruses to begin work on Zika virus.”
The mosquito-transmitted Zika virus typically causes relatively mild symptoms in infected adults. Prior to outbreaks of the virus in Micronesia and Southeast Asia in 2007, relatively few human cases had been reported. An ongoing epidemic of Zika virus began in early 2015 in Brazil and with it new evidence emerged that Zika virus infection of women during early pregnancy can result in microcephaly, a severe brain defect in infants.
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.