Here's an experiment: Turn off your lights, shine a blue flashlight on the cats in the room and look for the ones that turn neon green, like a glow stick.
That's how scientists at the Mayo Clinic identify cats that they've successfully treated against the feline immunodeficiency virus.
The AIDS epidemic in humans is well-known. Less known is that every year, millions of cats suffer and die from the disease.
To protect cats against feline AIDS, the Mayo Clinic and colleagues in Japan devised a treatment with a peculiar side effect. They took monkey genes that block HIV infection and injected them into cat eggs. Kittens born from those eggs produced AIDS-resistant protein in the same cells that get infected, effectively shielding them from the disease. Their offspring are also immune.
To tell the treated cats from the untreated ones, scientists added another simple ingredient to the mix: jellyfish genes, which make the modified cells glow a green color.
"It allows you to tell whether the gene of interest is in the cell without having to do an invasive test," Dr. Eric Poeschla, a molecular biologist with the Mayo Clinic, tells Guy Raz, host of weekends on All Things Considered. Scientists simply turn off the lights and shine a blue light to tell which cats have the AIDS-resistant gene.
The cats don't feel a thing, Poeschla says. "They're healthy and happy and they're playful."
The feline treatment could help other mammals down the line. The Mayo team isn't injecting human stem cells with the monkey-jellyfish concoction, but it is watching the cats for new insights.
"If they have the power to protect, then they could perhaps be used in the future in human gene therapy," Poeschla says.
Unfortunately, you can't get your own glow-in-the dark kitty just yet.
GUY RAZ, host: Here's a press release we received at the office this past week. The headline read: Mayo Clinic Teams Up with Glowing Cats Against AIDS. Now, as you can imagine, this got our attention. So we called Dr. Eric Poeschla. He's a microbiologist at the Mayo Clinic and the man behind the study to explain exactly how making cats glow in the dark could help in the fight against AIDS.
Dr. ERIC POESCHLA: That technique has been done now in many animals. This certainly isn't the first time. That ability to do that was discovered about 20 years ago, and it's tremendously useful in biological research.
RAZ: Okay. So there are two things going on here. One is you're trying to figure out if you can create cats that are resistant to feline AIDS, but at the same time you're injecting this jellyfish gene that causes them to glow.
RAZ: OK. So first of all, why do you want them to glow?
POESCHLA: It allows you to tell whether the gene of interest is in the cell without having to do an invasive test.
RAZ: My understanding is that you successfully inserted genes from a monkey, genes that make a protein that blocks the feline HIV infection that becomes AIDS. You inserted that into cat eggs, and essentially what? Those kittens born from those eggs can resist the infection?
POESCHLA: So those kittens born, we know they have the protein and they make the protein. They make it in the cells that are vulnerable to the virus; in other words, where the eggs' pathology plays out. And we know that when we draw the blood from the animals, their cells resist, relatively speaking, FIV replication.
We don't know yet whether the animals are protected, and that's the important main step to figure out. And that was the point of the whole project, really, to know what the power of these genes are at the whole animal level, and if they have the power to protect then they could perhaps be used in the future in human gene therapy, not by transgenesis, which obviously would never be done in a person, but by introducing them into the stem cells in the body that produce the white blood cells that are vulnerable to HIV.
So that's the hope in the future. There's no human application directly now or clinical trial now of course.
RAZ: Obviously, the AIDS side to this is the most important part of it, but you must have been impressed when you saw the cat glowing in the dark in the lab.
POESCHLA: Well, we were impressed. But the really interesting scientific question is the gene that went in, besides the jellyfish protein, can that protect the animal? Can that make the species resistant to FIV and AIDS? And we don't know that yet.
RAZ: And those cats are still alive?
POESCHLA: Those cats are still alive. They're healthy and happy, and they're playful. And you'd never know they're different from a regular cat unless you shine the light on them.
RAZ: So they still glow.
POESCHLA: They still glow.
RAZ: It doesn't wear off.
POESCHLA: It doesn't wear out. But I'll make the point that they don't just glow on their own. So if you were to let the cat loose in a dark room and just look, you won't see anything.
RAZ: You've got to shine the blue light on it.
POESCHLA: That's right.
RAZ: How can I get one?
POESCHLA: Well, I'm glad you asked that because you can't. And many people, well-meaning people, have emailed or written to see if animals are available, and the answer, of course, is no. There's no opportunity to obtain a cat. No animals will be sold or given out. They won't be released to breed in the outdoors. This is about doing research to improve both feline and human health.
And I'll also say - there's another question that we should answer because we get a lot of questions - there's no commercial aspects to this. Animals aren't sold to support the research. And to the contrary, we're dependent on receiving national institutes that help grant funding to go forward with it.
RAZ: Well, as a cat lover, I'm glad that they are both fighting AIDS and glowing in the dark, I must admit. Dr. Eric Poeschla is a molecular biologist and infectious disease specialist at the Mayo Clinic. You can read more about his AIDS-fighting glowing cats in the latest issue of the journal Nature Methods. And you can also see photos of the cats at our website, npr.og. Dr. Poeschla, thank you so much.
POESCHLA: Thank you. Transcript provided by NPR, Copyright National Public Radio.