from invasive microbes, is literally teeming with bacteria, which help break down waste. The presence of so many bacteria is a potential trigger for an immune system response. Why do T cells almost always ignore the small intestine, leaving this vital tissue unharmed?

"It's obvious that T cells must be able to ignore – or become 'tolerized' to – normal intestinal tissue," states Turley, who is also an assistant professor of pathology at Harvard Medical School. "But it has been unclear how dendritic cells, which are extremely sensitive to microbial agents such as bacteria, teach T cells to resist attacking healthy intestinal cells."

In the new study, Turley and her colleagues found that, in fact, dendritic cells aren't essential in creating tolerance in T cells. Instead, and unexpectedly, tolerance is produced by stromal cells from nearby lymph nodes. Although they aren't classified as "professional antigen-presenters," as dendritic cells are, the stromal cells serve the same purpose: exhibiting normal-cell antigens to the immune system.

"Our study points to a previously unknown mechanism of immune system tolerance," Turley explains. "When you think of the conditions in the small intestine, with so many millions of bacteria cells and so much opportunity for dendritic cells to stimulate an immune attack, it's remarkable that intestinal tissue is so rarely the target of an immune attack. Our findings demonstrate that the immune system has features that remain to be discovered."

Source-Eurekalert
RI
'"/>




Page: 1 2
Related medicine news :

1. Immune cells halt round in space
2. Immune function could benefit from exercise
3. Reviving the Immune System
4. Wrestling found To Be Good for the Immune System
5. Immune Boost With LHRH To Help Cancer And Transplant Patients
6. Researchers Find Out The Cause Of Immune Attacks Behind Hearing Loss
7. Block Immune System Chemical For Treating Asthma
8. Immune Response Of Human Beings Can Be Re-energized
9. Weizmann Institute of Science says Immune Cells Could Help Maintain Brain Function
10. Antidepressant drugs interacts with Immune cells
11. Specific Immune Mechanism against DNA viruses