Nantucket Current | Proposal for genetically modified mice to combat…

After a recent scientific breakthrough, MIT researchers were back on Nantucket this week to provide an update on their radical proposal to combat Lyme disease on the island by releasing thousands of genetically engineered white-footed mice to break the cycle of infection.

And they didn't come alone. A 60 Minutes camera crew and CBS chief medical correspondent Jon LaPook were on hand as the show plans an upcoming segment on the so-called “mice against ticks” proposal.

In a speech to the special committee on Wednesday evening, MIT biologist Kevin Esvelt, along with researcher and doctoral student Joanna Buchthal and tick researcher Sam Telford, announced that they had succeeded in creating the first genetically modified mouse that fights Lyme disease was resistant and that their immunity was passed on to subsequent generations. They achieved this by taking an anti-Lyme disease antibody and inserting it into the genome of a laboratory mouse.

Read the MIT presentation slides

“For years, everything we tried failed,” Buchthal said, describing how a new approach helped her team create embryos for the experiment by tracking the mice’s ovulation cycles based on their body temperature. “We were able to overcome a major bottleneck for the project.”

The goal, she said, is to breed mice that are immune to Lyme disease to prevent ticks from getting Lyme disease. This is intended to break the cycle of infection and reduce the number of cases on Nantucket, where the incidence rate is highest in the country. With the latest breakthrough, Esvelt and Buchthal are almost ready for field testing, which would be the precursor to a possible project on Nantucket. Such a field test would likely take place on a small private island somewhere off the coast of New England.

“Once federal regulators approve an initial field trial, the mice would be brought to this island and then we would see what happens to all the different organisms on this island,” Esvelt said. “But the other reason we’re here is we want this to be a community-led project throughout. That's why we came here before doing anything in the lab, and we want to keep it that way throughout the process. So if anyone in the community has something you'd like to look at in particular in this field trial, you probably have a few years left given the regulatory deadlines, but we want to hear from you. We want to hear from you because you live here and we don't live here, and that means you've probably discovered something or maybe you're thinking about something we haven't thought of yet. And that’s why we want to hear it from you.”

A number of residents raised questions about the impact on predators that eat mice, such as hawks, and how the mice would be distributed across the island if the project eventually moves forward.

“One of the things we've heard from the Nantucket community is that a lot of people here have said we don't want antibodies from other species in our white-footed mice,” Esvelt said. “So what's going to be in the white-footed mice are actually antibodies from vaccinated white-footed mice, and once we have those, the idea that all white-footed mice out there in the wild have antibodies is easy.” Just like we have antibodies when we're exposed to something When we become infected, our immune system responds by producing antibodies. And when a white-footed mouse becomes infected with Lyme disease, it also develops antibodies against the Lyme bacteria. So the idea is to make sure that we only put something into all mice that is already present in some mice. But that's never enough. We also need to test what impact this would have on predators like the reed falcon, for example, because we know that predators are often the cornerstones of the ecosystem. You have to make sure it doesn't harm them. As far as we can tell, it shouldn't harm them, as it's just another antibody in each of these animals' antibody soup. But that’s also why the mice wouldn’t be introduced in a trial on Nantucket.”