Discovery to help trick body into accepting transplantsJanuary 24th, 2009 - 4:26 pm ICT by IANS
Sydney, Jan 24 (IANS) A discovery can trick the body into accepting tissues or transplants as its own, eliminating the necessity for immunity suppressing medicines.Stacey Walters, a researcher in immunology at Garvan Institute of Medical Research, has found that mice genetically engineered to produce large amounts of B cell activating factor (BAFF) do not reject transplants.
She has shown that increased numbers of B cells (caused by boosted BAFF levels) in turn stimulate the production of T regulatory cells, which then control T cells, the body’s killer cells.
The surprising thing about the results is that B cells, which make antibodies, were not known to have any role in the production of T regulatory cells. Nor would it have been thought possible for them to influence the body’s response to a transplant, which has been considered a function of T cells only.
“In normal situations, something has to turn the immune system off once your body’s fought an invader, such as a virus. It’s the T regulatory cells that come in and say ‘enough’s enough’,” Walters explained.
Just to make sure it was the B cells that were provoking the changes, she repeated her experiments on a mouse in which B cells were genetically knocked out, but high BAFF levels preserved. She found that when there are no B cells, normal allograft rejection occurs, said a Garvan release.
Walter’s results provide an insight into previously unknown interrelationships between various classes of immune cells. Manipulating these relationships may offer a way of preserving organ grafts in the future without the need for toxic immunosuppressive drugs.
The findings have been published in the Journal of Immunology.