Rushville Republican

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
Featured Ads
AP Video
Argentina to Face Germany in World Cup Final Service Held for 200 Whose Bodies Went Unclaimed Kim Kardashian Hits Up Valentino Show in Paris "Hotwives" Spoofs Reality TV Israeli Offensive Escalates in Gaza Attack Dozens Gain Citizenship As Debate Continues Dodgers Found Partly Responsible in Fan Beating Children of Deported Parents Speak Out GOP: Immigration a 'human Rights Issue' Raw: 10-year Sentence for Ex-New Orleans Mayor Raw: Fans Gather for Argentina-Netherlands Match Froome Crashes Out on Bumpy 5th Tour Stage Obama Talks Economy, Slams Republicans Police: Prostitute Accused in Overdose Death Tornadoes Kill Four in Central New York McCaskill: Campus Assault Survey Is Wake Up Call Raw: Obama Shoots Pool in Denver Typhoon Nears Japan's Main Islands Day After: Brazil Reeling in WC Loss Weaver Reprises Ripley Role for 'Alien' Game
Hyperlocal Search
Premier Guide
Find a business

Walking Fingers
Maps, Menus, Store hours, Coupons, and more...
Premier Guide
Parade
Magazine

Click HERE to read all your Parade favorites including Hollywood Wire, Celebrity interviews and photo galleries, Food recipes and cooking tips, Games and lots more.