MIT researchers propose release of genetically engineered mice on Nantucket

NANTUCKET, Mass. -- On the picturesque island of Nantucket, residents are considering a radical approach to fight a disease that's haunted the island for decades.

Dr. Timothy Lepore says he sees upwards of 100 cases of Lyme disease each year, an especially high number for an island with a population of 10,000 residents.

One of those patients is Illya Kagan, a painter who was first diagnosed with the tick-borne illness when he was a teen.

"I was suddenly fatigued and then had a bullseye rash," said Kagan.

It was a few years later when it came back that scared him. "I woke up one morning and half of my face wasn't working" said Kagan.

The temporary paralysis is called Bell’s Palsy and is a potential side effect of Lyme disease.

Kagan says he’s been infected five times, something Dr. Lepore said isn't uncommon on the island where as many as 30 percent of households deal with Lyme disease.

Finding the source of the problem

Ticks live in shrubs and underbrush, waiting for an unsuspecting animal to come by that they can latch on to.

Deer and mice are some of the most common targets, but people are also unsuspecting victims.

On Nantucket, the high deer population is directly correlated to the amount of ticks. One possible solution was to reduce their numbers, but that was unpopular with residents, Lepore said.

The white footed mouse is another common tick target. According to researchers, it’s the biggest carrier of Lyme disease on the island making it a prime opportunity for experimenting with new techniques to reduce transmission to humans.

Experimenting with genetically modified rodents.

MIT evolutionary biologist Dr. Kevin Esvelt has developed an idea to modify the mice native to the island and release hundreds of thousands into the environment.

"Ticks aren't born infected, they usually get infected when they bite an infected mouse," Esvelt told Boston 25 News.

Esvelt is director of the Sculpting Evolution Group and had the idea to engineer mice that are immune to tick-borne diseases. They call it "Mice against Ticks" and the hope is to flood Nantucket with enough of these genetically engineered mice, that they would pass the immunity gene down to their offspring for multiple generations. 

"We'll disrupt the cycle of transmission and there will be many fewer infected ticks in the environment and there for many fewer human infections,” Esvelt said.

Esvelt says they’ve already identified the genes necessary to engineer the immune mice and it's now time to put the theory to the test. He says they’re also offering the option of altering the mice’s genes so the ticks won't feed on them.

"Ticks that bite the mice, well the mice will taste bad, sort of like mouse blood becomes hot sauce and so the ticks will fall off and most won't find another host and so they'll die," he said.

Planning and testing before going full-scale

The plan is to first test the mice on an uninhabited island before releasing them on Nantucket, which Esvelt estimates is at least seven years away if everything goes perfectly.  If the experiment drastically reduces the amount of tick borne disease on the island, Esvelt said he believes the genetically engineered mice could eventually be used on the mainland.

According to the Massachusetts Department of Public Health, almost 9,000 cases of Lyme disease have been reported across the state between 2015 and 2016.

Dr. Sam Telford is a professor of infectious disease at Tufts University and has been working with Esvelt on educating the residents of Nantucket through a series of town hall meetings. Telford has spent his entire career fighting Lyme disease and believes in the science behind using engineered mice.

“This is the new generation of interventions,” said Telford. “The greater hope is using Lyme disease as an example, we can attack the infections of people globally in areas that have rodents as the reservoirs.”

Gaining support from Nantucket residents

Malcolm MacNab is the chairman of the Nantucket Board of Health and is open to the idea of tinkering with mother nature to combat Lyme disease. 

"I think if we do it correctly and slowly, we have the chance of seeing if it works and if it's safe," said MacNab.

The first step is convincing Nantucket residents like Betsy Brooks. Brooks was pregnant with twins when she contracted Lyme disease four years ago and now worries about her children when they go out and play.

"It's terrifying. After everything it's tick check, tick check, tick check," she said.

From what she knows about the project, Brooks thinks using the genetically engineered mice is the best solution to reduce Lyme disease on the island, although she does have some questions.

"What does this mean for indoor/outdoor cats or birds of prey? How is it going affect them if eat genetically modified mice?" Brooks asked.

It’s a question Esvelt hears repeatedly from concerned residents. He says they’ll know more after studying the mice on the uninhabited island for a couple years. If everything goes as planned, they’ll move to the next phase of releasing the mice on Nantucket. Planning on how many mice to release and what type of modifications will be made will take years and that ultimately comes down to a vote from Nantucket residents.


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