The Ottumwa Courier

Community News Network

November 8, 2013

Why late nights are bad for your immune system

Jet lag, shift work and even late nights staring at your tablet or smartphone may be making you sick. That's because the body's internal clock is set for two 12-hour periods of light and darkness, and when this rhythm is thrown off, so is the immune system. One reason may be that the genes that set the body clock are intimately connected to certain immune cells, according to a new study.

The finding "was a happy accident," says Lora Hooper, an immunologist at the University of Texas Southwestern Medical Center in Dallas. She and her colleagues were studying NFIL3, a protein that guides the development of certain immune cells and turns on the activity of others. The gene for this protein is mutated in some human patients with inflammatory bowel disease, and mice lacking the gene for NFIL3, the team found, had more so-called TH17 cells in their intestines.

These cells are a type of immune cell known as a T cell. They get their name from a signal they produce, called interleukin 17, which tells other T cells to increase the immune response. In normal numbers, TH17 cells, which live in the intestines, help the body fight bacterial and fungal infections. But when there are too many, the immune defense begins to cause illness rather than prevent it. Boosting NFIL3 levels in T cells growing in lab cultures resulted in fewer of them turning into TH17 cells, the researchers found, suggesting that the protein's job is to prevent T cells from going into that area of specialization. The absence of the protein, the team concluded, leads to runaway TH17 activity.

At this point, the researchers had no reason to suspect a connection to our body's internal timekeeping system — also known as our circadian clock — which responds to daily cycles of light and dark. But as they continued to explore the connection between NFIL3 and TH17 cells, they found that some of the proteins produced by the body's "clock genes" attach to the NFIL3 genes. What's more, cultured cells and mice whose clock genes were experimentally tampered with produced fewer TH17 cells. The researchers surmise that a key protein in the clock network binds to the NFIL3 gene to keep the production of TH17 cells synchronized with periods of light and darkness. And the team found that normal mice produce less NFIL3, and thus more TH17 cells, during the day than at night.

Text Only
Community News Network
  • Wal-Mart to cut prices more aggressively in back-to-school push

    Wal-Mart Stores plans to cut prices more aggressively during this year's back-to-school season and will add inventory to its online store as the chain battles retailers for student spending.

    July 21, 2014

  • Hospitals let patients schedule ER visits

    Three times within a week, 34-year-old Michael Granillo went to the emergency room at Northridge Hospital Medical Center in Los Angeles because of intense back pain. Each time, Granillo, who didn't have insurance, stayed for less than an hour before leaving without being seen by a doctor.

    July 21, 2014

  • Starved Pennsylvania 7-year-old weighed only 25 pounds

    A 7-year-old Pennsylvania boy authorities described as being so underweight he looked like a human skeleton has been released from the hospital.

    July 21, 2014

  • Malaysians wonder 'Why us?' after second loss of airline jet

    It was all too familiar. Grieving families rushing to airport. The flashing television graphics of a plane's last radar appearance. The uncomfortable officials before a heavy thicket of microphones.
    For many Malaysians, the disappearance of Flight 370 in March has been a long trauma from which the nation has not yet recovered.

    July 18, 2014

  • A quarter of the world's most educated people live in the 100 largest cities

    College graduates are increasingly sorting themselves into high-cost, high-amenity cities such as Washington, New York, Boston and San Francisco, a phenomenon that threatens to segregate us across the country by education.

    July 18, 2014

  • Your chocolate addiction is only going to get more expensive

    For nearly two years, cocoa prices have been on the rise. Finally, that's affecting the price you pay for a bar of chocolate - and there's reason to believe it's only the beginning.

    July 18, 2014

  • Facebook tests button to let people shop from its website

    Members on desktop computers or mobile devices can click a "buy" button to make purchases through advertisements or other posts on the world's largest social network, the Menlo Park, California-based company said Thursday in a blog post.

    July 17, 2014

  • The terrible history of passenger planes getting shot out of the sky

    What is more clear is that, if initial reports are true, this would be the deadliest incident of a civilian passenger plane being shot down in modern memory. In some instances, the causes of the disaster are still shrouded in mystery. Here are some of the worst events.

    July 17, 2014

  • 130408_NT_BEA_good kids We're raising a generation of timid kids

    A week ago, a woman was charged with leaving her child in the car while she went into a store. Her 11-year-old child. This week, a woman was arrested for allowing her 9-year-old daughter to go to the park alone. Which raises just one question: America, what the heck is wrong with you?

    July 17, 2014 1 Photo

  • web_starbucks-cof_big_ce.jpg Starbucks sees more Apple-like stores after Colombia debut

    This week Starbucks opened its first location in Colombia — a 2,700-square-foot store with a heated patio, concrete columns, mirrors on the ceiling and walls of colorful plants.

    July 17, 2014 1 Photo

Obituaries
Record
Facebook
AP National