Scientists have found that natural killer (NK) cells can recognize many different viruses including global pathogens such as Zika, dengue and Hepatitis C viruses, through a single receptor called KIR2DS2. This work comes from the University of Southampton and appeared last week in Science Immunology.
Vaccines work by stimulating the immune system to the coat of proteins on a virus. However, often enough, a virus can change their coat proteins. This team has found that the NK receptor, KIR2DS2, is able to target a non-variable part of the virus called the NS3 helicase protein, which is essential in making the virus work properly.
"The NS3 helicase protein could be the key in unlocking the defense of lethal viruses that affect so many people around the world. It is very exciting to discover that other viruses similar to Hepatitis C, such as Zika virus, dengue virus, yellow fever virus, Japanese encephalitis virus and in fact all flaviviruses, contain a region within their NS3 helicase proteins that is recognized by exactly the same KIR2DS2 receptor. We believe that by targeting this NS3 helicase region, we could make a new type of vaccine based upon natural killer cells, which can be used to help protect people from these infections," says lead researcher Salim Khakoo, M.D., professor of Hepatology.
The scientists analyzed DNA from more than 300 patients exposed to Hepatitis C and showed that the KIR2 receptor was associated with successfully clearing the virus. The team then identified that the immune system targeted the NS3 helicase protein of this using the receptor and found that it prevented the virus multiplying.
The researchers now are on a mission to determine whether these KIR2DS2+ NK cells are protective during acute flaviviral infections, and are hoping to develop a vaccine that targets natural killer cells. They believe that a similar process could be used to target cancer.
Image: Zika and dengue are among the diseases spread by mosquitoes. Image courtesy of the University of Southampton.