According to a statement, the finding could lead to new drugs for organ transplant patients and patients with auto-immune diseases such as lupus and Crohn's disease.
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"We now have evidence that the omentum is not just fat sitting in the belly," said Makio Iwashima, an associate professor in the Department of Microbiology and Immunology and author of a study published in the June 6 issue of PLoS ONE.
The omentum is a membrane that lines the abdominal cavity and covers most abdominal organs. It is a repository for fat tissue.
A research team headed by Iwashima and lung transplant surgeon Robert Love, examined the effect that mouse omentum cells had on T lymphocyte cells from a mouse.
T cells are the immune system's first line of defense against infection. They identify, attack and destroy bacteria, viruses and other infectious agents.
Normally, T cells multiply in response to an infectious agent, such as an antibody. But when researchers put omentum cells in with activated T cells that had been exposed to antibodies, the T cells did not multiply as they normally would, but instead died.
The omentum cells had this effect only on T cells that had been activated. Omentum cells did not have any effect on inactive T cells.
It appears that omentum cells secrete a substance that tamps down the immune system.
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This discovery could lead to new drugs that would suppress the immune system with fewer side effects than those caused by immune-suppressing drugs now in use.
Such drugs could be used, for example, to suppress the immune system in a patient who has received a lung transplant.
In addition to modulating the immune system, the omentum also appears to play a critical role in regenerating damaged tissues, Iwashima said in a statement.
The omentum contains mesenchymal stem cells that migrate to the site of an injury and help regenerate tissue. Mesenchymal stem cells are cells that have the ability to develop into various types of specialized cells.
In this study, researchers showed that, in tissue-culture flasks, omentum cells can differentiate into lung-type cells as well as bone cells.
Iwashima believes the omentum may be the organ specified for tissue healing and regeneration.
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Pictures Of The Day: 7 June 2012
(01 of09)
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An Egyptian child with the colours of his national flag painted on his face attends a protest against the verdicts handed down in ex-president Hosni Mubarak's murder trial in Cairo's landmark Tahrir Square on June 6, 2012. Mubarak, 84, and his interior minister Habib al-Adly were sentenced to life in prison on June 2, but six security chiefs were acquitted of the killings of demonstrators during last year's uprising that left some 850 people dead and ousted the veteran president. (Photo credit: MOHAMMED ABED/AFP/GettyImages)
(02 of09)
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The headstone for the final resting place of US science fiction writer Ray Bradbury is seen at Westwood Village Memorial Park Cemetery in Los Angeles, California, June 6, 2012. Bradbury, whose dystopian works served as cautionary tales about perilous futures and reflected the anxieties of post-war America, died June 5, 2012 after a long illness. He was 91. (Photo credit: ROBYN BECK/AFP/GettyImages)
(03 of09)
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An F-16 drops chaff cartridges during the "Lien Yung" annual joint forces exercises, Thursday, June 7, 2012 in Pingtung County, southern Taiwan. (Photo credit: AP Photo/Wally Santana)
(04 of09)
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A white phosphorous shell explodes on target during the "Lien Yung" annual joint forces exercises, Thursday, June 7, 2012 in Pingtung County, southern Taiwan. (Photo credit: AP Photo/Wally Santana)
(05 of09)
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A Kashmiri boatman rows a boat while a passenger holds an umbrella during rain on Dal Lake in Srinagar on June 7, 2012. Thousands of holiday goers have arrived in Kashmir valley to enjoy the beauty of its landscapes, as violence ebbs in the Muslim-majority state wracked by insurgency since 1989. An armed insurgency against Indian rule in Kashmir has claimed 47,000 lives since 1989 with separatists putting the toll twice as high. (Photo credit: TAUSEEF MUSTAFA/AFP/GettyImages)
(06 of09)
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U.S. Secretary of Defense Leon Panetta (C) speaks with U.S. Ambassador to Afghanistan Ryan Crocker (2nd R) and the head of NATO coalition forces in Afghanistan General John Allen (3rd L) as he arrives at Kabul International Airport on June 7, 2012 in Kabul, Afghanistan. Panetta's arrival in the Afghan capital, on an unannounced trip to review the status of the war and to discuss troop draw-down plans, is taking place in the wake of a suicide attack in the capital and reports of an errant NATO airstrike killing civilians in the south of the country the previous day. (Photo credit: Jim Watson - Pool/Getty Images)
(07 of09)
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Environmental activists from Greenpeace dressed as 'coal demons' protest in front of the Asian Development Bank (ADB) during the 7th Annual Clean Energy meeting in Manila on June 7, 2012. The coal demons, painted black, called on the ADB to stop funding projects using coal in the Philippines, Indonesia, Thailand and Vietnam. (Photo credit: JAY DIRECTO/AFP/GettyImages)
(08 of09)
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Russia's national football team cheerleaders perform as the team fans departure to Poland for the Euro 2012 football championship at Belarus railway station in Moscow, on June 7, 2012. The special destination train will deliver the Russian team's fans to the first match against Czech Republic. (Photo credit: KIRILL KUDRYAVTSEV/AFP/GettyImages)
(09 of09)
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Oklahoma City Thunder guard James Harden (13) celebrates after hitting a 3-pointer as San Antonio Spurs small forward Kawhi Leonard (2) walks away during the second half of Game 6 in the NBA basketball Western Conference finals, Wednesday, June 6, 2012, in Oklahoma City. The Thunder won 107-99. (Photo credit: AP Photo/Sue Ogrocki)