For decades, scientists have suspected that the immune system is involved in Parkinson's disease but didn't know how because the body's defenses don't typically target neurons. Researchers now report that immune cells may be attacking a protein that builds up in the brain when someone has the disease. The finding suggests an avenue for new treatment by blocking the immune response with drugs.

What they did: Researchers analyzed blood from 67 patients with Parkinson's disease and 36 healthy people, and found that in people with the disease the body's immune T cells recognized neurons displaying specific fragments of a protein called alpha-synuclein, which accumulates in the brain when someone has Parkinson's. In healthy people, there was no response.

How it might work: The reaction to specific pieces of the protein is key - it could explain why immune reaction is localized to particular neurons. The immune system may recognize alpha-synuclein as foreign and try to clear it, in the process destroying dopamine-producing neurons where the protein accumulates. Those neurons are at the center of Parkinson's - depleting dopamine causes the disease's hallmark tremors. Most neurons don't produce the molecules that the immune system recognizes and then attacks - but the dopamine-producing ones do.

"It's a novel idea. If it holds up, it will shift the paradigm for understanding the disease," says NIH's Mark Cookson, who wasn't involved in the study.

Big question: Does the immune system target these neurons or is the reaction is inadvertent? That would indicate whether the reaction can be blocked with drugs - something the researchers plan to test.

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Mary Trump book: How she leaked Trump financials to NYT

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In her new memoir, President Trump's niece reveals how she leaked hordes of confidential Trump family financial documents to the New York Times in an effort to expose her uncle, whom she portrays as a dangerous sociopath.

Why it matters: Trump was furious when he found out recently that Mary Trump, a trained psychologist, would be publishing a tell-all memoir. And Trump's younger brother, Robert, tried and failed to block the publication of "Too Much and Never Enough: How My Family Created the World's Most Dangerous Man."

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Coronavirus dashboard

Illustration: Eniola Odetunde/Axios

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  2. U.S.: Total confirmed cases as of 3:30 p.m. ET: 2,963,244 — Total deaths: 130,813 — Total recoveries: 924,148 — Total tested: 36,225,015Map.
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  4. Congress: Trump administration notifies Congress of intent to withdraw from WHO.
  5. Public health: Fauci says it's a "false narrative" to take comfort in lower coronavirus death rate.
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Fauci: "False narrative" to take comfort in lower coronavirus death rate

Anthony Fauci testifies in Washington, D.C., on June 30. Photo: Al Drago/AFP via Getty Images

Anthony Fauci said at an event with Sen. Doug Jones (D-Ala.) on Tuesday "that it's a false narrative to take comfort in a lower rate of death" from the coronavirus in the U.S., warning: "There’s so many other things that are dangerous and bad about the virus. Don’t get into false complacency."

The big picture: The mean age of Americans currently being infected by the virus has declined by 15 years compared to where it stood several months ago. This has been one contributing factor in the lower death rate the U.S. has experienced during the recent surge in cases, since "the younger you are, the better you do, and the less likely you're gonna get seriously ill and die," Fauci said.