Scientists believe they may have found a preventative therapy for Type 1 diabetes, by making the body's killer immune cells tolerate the insulin-producing cells they would normally attack and destroy, prior to disease onset.
Type 1 diabetes is an autoimmune condition, where the body attacks its own insulin producing cells. It is very serious, with a sudden and dramatic onset, usually in youth. People with Type 1 diabetes must maintain an insulin-monitoring and insulin-injecting regimen for the rest of their lives.
PhD student Eliana Mariño and Dr. Shane Grey (pictured) from the Garvan Institute of Medical Research in Sydney, have demonstrated how a particular molecule may be used in the future as a preventative therapy.
The body's immune cells, or white blood cells, include B cells and T cells. B cells make antibodies and present 'antigens' to T cells, allowing them to recognize, and kill, invaders.
In previously published studies about Type 1 diabetes, Mariño and Grey showed that groups of B cells migrate to the pancreas and pancreatic lymph nodes, presenting specific insulin antigen to T cells. In other words, B cells go to the disease site and tell T cells to kill the cells that produce insulin.
"Taking that work further, our current study looks at different ways of subduing B cells, and how that affects development of the disease," said Grey.
Working with mice that spontaneously develop Type 1 diabetes, Eliana Mariño found that if she blocked BAFF (a hormone that controls survival of B cells) prior to onset, none of the mice developed diabetes.
"This is a remarkable finding, as other B cell depletion methods tested elsewhere have just delayed or reduced disease incidence," said Eliana.
When B cells were depleted, the regulators of the immune system (a subclass of T cells known as T regulatory cells) rose in numbers.
By removing B cells from the picture for a while, it appears you allow T regulatory cells to function as they should, subduing killer T cells and somehow making them tolerant of the insulin producing cells.
Illustration: Garvan Institute of Medical Research.
Garvan Institute of Medical Research News Release (04/29/09)
Science Daily (05/04/09)
Abstract (Diabetes; (03/31/09))