Virus Hunters

In his race to be the first scientist in the world to find a nematode virus, Chris Sullivan had an unusual team of field biologists aiding him this summer—eight high school kids from in and around Austin.

In his race to be the first scientist in the world to find a nematode virus, Chris Sullivan had an unusual team of field biologists aiding him this summer—eight high school students from in and around Austin. They were there as part of a National Science Foundation-funded grant to Dr. Sullivan that enabled him to collaborate with University Outreach, a UT-sponsored, state-wide effort to help underrepresented students prepare themselves for college.

Every morning for two and a half weeks, Sullivan and undergraduate members of his lab took the kids through a kind of blast course in research biology. It consisted of short lessons in the science basics, instruction in lab techniques, a few field trips, and one very ambitious research project.

“The idea was this,” says Sullivan, assistant professor of biology. “The nematode worm has been incredibly valuable to biologists as a model organism. Research with it has been the basis of a number of Nobel Prizes. It’s been used with great success to understand bacterial pathogens, and in theory we should be able to use it to study viruses. We haven’t been able to, however, because no one’s found a virus in a nematode. Yet they must exist in nature. Any virologist will tell you that every organism is susceptible to some viruses. They’re there. We just have to find them.”




Rather than follow in the footsteps of past nematode virus-hunters, who’ve kept their search within the confines of the laboratory, Sullivan conceived an approach that took him, and the kids, out into the wild. Specifically, they took a trip to the Lady Bird Johnson Wildflower Center, where each kid was given a shovel and a bin and told to dig up some dirt.

“The Wildflower Center let us have access to all their microenvironments, which was important because we wanted diversity,” says Sullivan. “Our thought was that if you take soil that has healthy worms in it, they should all have viruses, just in the way that people are always walking around with viruses in us.”

Sullivan and the kids then brought their soil samples back to the lab, where they ran a pretty simple experiment. They put lab nematodes that were designed to be immunologically compromised into soil with the wild nematodes. Then Sullivan and his crew looked to see how those batches of immunocompromised worms survived and reproduced.

“We took RNAi defective worms, which are the worm equivalent of bubble boy, and we took them out of the comfy laboratory existence they’ve lived for the last five decades, and had them cozy up next to wild nematodes in soil,” says Sullivan. “The idea is that maybe that will allow them to be infected. Maybe soil causes abrasion in the dermis that allows the virus to transmit, or maybe it’s as simple as being around worms that are infected in a normal environment, allowing for normal routes of transmission.”

If there does prove to be a significant decline in the numbers of the lab nematodes in any of the samples—and the experiment is still ongoing—then Sullivan can start searching for the actual viruses. And if he finds them, he can begin to map out the contours of the nematode “virome,” and help lay the groundwork for using the nematode as a model organism for studying viral infections in much the same way that it's been used to study bacterial infections.

“There’s very powerful things you can do with the worms, little tricks in genetics and so on, that you can only do in worms, and we presume we’d learn a lot about basic viral interactions,” says Sullivan. “My purely selfish hope, as someone who’s spent my career dedicated to a certain type of virus that causes tumors, is that some of the viruses we’d find in the nematode would look something like those.”

Even if this first effort to find a nematode virus fails, says Sullivan, the experience of working with the high school students was rewarding on its own terms.

“I’m surprised at how much fun I had,” he says. “We ate pizza. We taught them a little bit of science each day. And we did some science, which was hard in only two and a half weeks, but we have real hope that there’s something in that soil.”