Transmission of Zika virus by mosquitoes has been declared a public health emergency by the World Health Organization. There is no known treatment for the disease, which has been linked to microcephaly, a birth defect in which children are born with underdeveloped brains, and with Guillain-Barre syndrome in children and adults. For now, avoiding mosquito bites is the best countermeasure.
While nearly everyone has heard of Zika by now, some may not be as aware of CRISPR/Cas9. CRISPR/Cas9 is the name scientists have given the most exciting tool in genetic engineering to be developed so far. It consists of a way to link a sort of DNA-cutting tool with a map of where it should make its cut. Previous tools would cut much more randomly, leaving scientists to sort out the cuts that work from the ones that fail. CRISPR/Cas9 offers precision and therefore speed.
A lot of talk on the topic of CRISPR/Cas9 revolves around how soon scientists will begin crafting the ultimate super human in spite of the ethical concerns and how the technology will affect work on genetically modified plants and animals in the service of the human food chain. But CRISPR/Cas9 is proving to be a boon to researchers seeking to learn how we can combat the threat of an evolving pandemic that has spread from a macaque in Africa to the American and Asian continents already.
Fortunately for medicine, viruses are so small that they do not have the equipment to reproduce themselves. This forces viruses to find a host and take over the equipment in the host's cells in order to survive. So if doctors can learn which human proteins a Zika virus borrows in order to replicate, they can pursue options to block the virus - stopping its spread.
Usually, this involves a lot of hunting and pecking, looking for a single protein in a haystack of proteins. But University of Massachusetts Medical School have developed a CRISPR/Cas9 based screening process that speeds up the process. Led by Abraham Brass, assistant professor in microbiology & physiological systems, the UMMS team uses CRISPR/Cas9 to knock out precisely one protein at a time, and watches to see when the Zika shows signs of trouble. When Zika struggles to survive, they have found a protein key to the virus - and a target for medicines to stop it.
Brass comments on their success with admirable selflessness:
We plugged Zika virus into our system and immediately began studying it. What might have taken much longer to build from the ground up, we were able to turn around in a few short months. Our goal was to get the screens done, find what the viruses need to grow, and then get the data out to the rest of the research community right away.
We will be debating whether CRISPR-engineered humans are a good idea for some time to come, but this work demonstrates that scientific tools are not good or bad, they are merely tools. When CRISPR can save lives and help babies be born with all their vast human potential, its a good tool.
Read the full study online in Cell Reports.