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Why Autoimmune Diseases Cause the Body to Attack Itself

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A new study published in the journal Cell explores the cellular "runaway train" that allows lupus and other autoimmune diseases to spread throughout the body.

Autoimmune disease is exactly what it sounds like—the body mistakenly fighting itself. This attack may take the form of type 1 diabetes, celiac disease, rheumatoid arthritis, inflammatory bowel disease, or lupus, among others. But what begins as a local problem often eventually goes global.

"Once your body's tolerance for its own tissues is lost, the chain reaction is like a runaway train," co-author Michael Carroll of Boston Children's Hospital and Harvard Medical School said in a statement.

The disease tricks the body into expanding its attack. In a process called epitope spreading, autoantibodies target more and more tissues and organ systems over time, causing new symptoms like joint pain, kidney damage, and severe skin rashes.

To find out how it happens, Carroll and his colleagues zoomed way, way in to examine the progression of lupus in the tissues of lab mice.

"Lupus is known as 'the great imitator' because the disease can have so many different clinical presentations resembling other common conditions," first author Søren Degn, of Boston Children's Hospital and Aarhus University, said in the statement.

"It's a multiorgan disease with a plethora of potential antigenic targets, tissues affected and 'immune players' involved. Lupus is considered a prototypic autoimmune disease, which is why it's so interesting to study."

The researchers used what's called a confetti technique, marking different types of diseased B cells with different colors, then watching the colored dots multiply, scatter, and spread.

Graphic of multicolored autoantibodies
Immune cells called B cells battle each other to produce the best antibody. Here, green represents the B cells that produce the "winning" antibody and stamp out competing B cells (other colors).
Carroll Lab/Boston Children's Hospital

The confetti images revealed a microscopic soap opera, as the different colors struggled for dominance and power. As time went on, the makeup of the confetti shifted. One color, or cell type, had won.

Those toxic cells then began converting their neighbors.

"Over time, the B cells that initially produce the 'winning' autoantibodies begin to recruit other B cells to produce additional damaging autoantibodies—just as ripples spread out when a single pebble is dropped into water," Degn said.

The researchers were surprised but excited by their results, which they believe could someday lead to new types of treatment.

"Blocking germinal centers in the midst of an autoimmune response could potentially block the epitope-spreading process," Carroll said. "If you could stop the adaptive immune system for a transient amount of time, it might allow the body to reset its immune responses and shut off the autoreactivity."

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Medicine
New Cancer-Fighting Nanobots Can Track Down Tumors and Cut Off Their Blood Supply
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Scientists have developed a new way to cut off the blood flow to cancerous tumors, causing them to eventually shrivel up and die. As Business Insider reports, the new treatment uses a design inspired by origami to infiltrate crucial blood vessels while leaving the rest of the body unharmed.

A team of molecular chemists from Arizona State University and the Chinese Academy of Sciences describe their method in the journal Nature Biotechnology. First, they constructed robots that are 1000 times smaller than a human hair from strands of DNA. These tiny devices contain enzymes called thrombin that encourage blood clotting, and they're rolled up tightly enough to keep the substance contained.

Next, researchers injected the robots into the bloodstreams of mice and small pigs sick with different types of cancer. The DNA sought the tumor in the body while leaving healthy cells alone. The robot knew when it reached the tumor and responded by unfurling and releasing the thrombin into the blood vessel that fed it. A clot started to form, eventually blocking off the tumor's blood supply and causing the cancerous tissues to die.

The treatment has been tested on dozen of animals with breast, lung, skin, and ovarian cancers. In mice, the average life expectancy doubled, and in three of the skin cancer cases tumors regressed completely.

Researchers are optimistic about the therapy's effectiveness on cancers throughout the body. There's not much variation between the blood vessels that supply tumors, whether they're in an ovary in or a prostate. So if triggering a blood clot causes one type of tumor to waste away, the same method holds promise for other cancers.

But before the scientists think too far ahead, they'll need to test the treatments on human patients. Nanobots have been an appealing cancer-fighting option to researchers for years. If effective, the machines can target cancer at the microscopic level without causing harm to healthy cells. But if something goes wrong, the bots could end up attacking the wrong tissue and leave the patient worse off. Study co-author Hao Yan believes this latest method may be the one that gets it right. He said in a statement, "I think we are much closer to real, practical medical applications of the technology."

[h/t Business Insider]

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New Peanut Allergy Patch Could Be Coming to Pharmacies This Year
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About 6 million people in the U.S. and Europe have severe peanut allergies, including more than 2 million children. Now, French biotechnology company DBV Technologies SA has secured an FDA review for its peanut allergy patch, Bloomberg reports.

If approved, the company aims to start selling the Viaskin patch to children afflicted with peanut allergies in the second half of 2018. The FDA's decision comes in spite of the patch's disappointing study results last year, which found the product to be less effective than DBV hoped (though it did receive high marks for safety). The FDA has also granted Viaskin breakthrough-therapy and fast-track designations, which means a faster review process.

DBV's potentially life-saving product is a small disc that is placed on the arm or between the shoulder blades. It works like a vaccine, exposing the wearer's immune system to micro-doses of peanut protein to increase tolerance. It's intended to reduce the chances of having a severe allergic reaction to accidental exposure.

The patch might have competition: Aimmune Therapeutics Inc., which specializes in food allergy treatments, and the drug company Regeneron Pharmaceuticals Inc. are working together to develop a cure for peanut allergies.

[h/t Bloomberg]

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