02 October 2012

Antibodies against diabetes: details

Diabetes mellitus: a new weapon against an old disease

Vladimir Fradkin, Deutsche WelleUntil now, type I diabetes was considered an incurable disease.

Now doctors have managed to develop an effective therapy. At least they've already cured the mice.

Diabetes mellitus is a severe violation of carbohydrate metabolism, as a result of which the oxidation of sugar present in the human body stops. The disease is associated with a deficiency of insulin, a hormone produced by the so–called beta cells of the islets of Langerhans of the pancreas. In most cases, doctors are dealing with type 2 diabetes mellitus – this form of diabetes usually develops in people over forty years old and is caused by the fact that the pancreas begins to produce less and less insulin.

Fortunately, doctors have to deal with diabetes mellitus of the first type less often, but this disease develops already in youth or even in childhood and proceeds much harder. It usually has a so-called autoimmune character: for an unknown reason, the T-cells of the immune system begin to perceive the beta cells of the pancreas as foreign and destroy them, as a result of which the production of their own insulin in the body completely stops.

It is possible to reverse the development of diabetes!The life of such patients depends entirely on the timely administration of insulin from the outside, otherwise the patient falls into a diabetic coma and dies.

Until now, this disease was considered incurable, but now American immunologists have achieved great success in the treatment of type I diabetes mellitus. True, so far only in mice, but it's a bad start.

Moreover, in mice, the disease proceeds in almost the same way as in humans, says project leader Roland Tisch, a researcher at the Department of Microbiology and Immunology at the University of North Carolina at Chapel Hill School of Medicine: "Most of the effects caused by insulin deficiency in laboratory animals are observed in humans. Mice weaken, lose weight quickly, and if they are not injected with insulin, they die."

However, the diabetic mice in the laboratory of Roland Tisch immediately after the appearance of their first symptoms, the researchers gave two injections with an interval of 3 days. But it was not insulin, but a solution containing special antibodies. The scientist explains: "The main question for us was: is it possible to reverse the development of diabetes in mice? And the answer was positive."

Mice recover once and for allThe antibodies used by American specialists neutralize the very T cells of the immune system that destroy the insulin-producing beta cells of the pancreas.

The effect of the antibodies exceeded the wildest expectations of the researchers. "In some animals, the blood sugar content returned to normal after two days, most of them took six days to fully recover from diabetes. We continued observations for several months, in some cases even more than a year. And no relapses – the animals recovered once and for all."

Actually, immunotherapy against diabetes is not a new thing. Special antibodies capable of blocking T-cells of the immune system have already been tested on humans – and even with some success. But there is no need to talk about a genuine breakthrough here yet. Roland Tisch explains: "The main drawback of these antibodies is that they destroy – at least for some time – all T-lymphocytes indiscriminately. When it comes to those T-killers that destroy insulin-producing beta cells of the pancreas, then this is, of course, good. But if antibodies destroy all T-lymphocytes in a row, then the body becomes completely defenseless and loses the ability to resist any infection, any pathogenic bacteria and viruses."

The main advantage of antibodies is high selectivityAnother thing is the antibodies obtained and used by Roland Tish and his colleagues.

"True, our antibodies also bind to all T-lymphocytes in a row, but they do not destroy them," says the researcher. – Only those T cells that cause pancreatic dysfunction are destroyed. For example, T-lymphocytes in the blood remain fully active, so that the mouse body forms a normal immune response to infection."

Specialists from Chapel Hill do not yet fully understand themselves what explains such selectivity of their antibodies. But the fact that therapy is effective only against animals that have recently become ill with diabetes seems logical: after all, if the "enraged" T-lymphocytes have managed to destroy a significant number of beta cells, then no antibodies will be able to help, it will not be possible to restore the functioning of the pancreas. "Our goal, of course, is to test similar antibodies in humans," says Roland Tisch. "The antibodies we used in this study are mouse antibodies, and they bind only to mouse immune cells. We are currently busy trying to get a human analogue of such antibodies."

Portal "Eternal youth" http://vechnayamolodost.ru02.10.2012

Found a typo? Select it and press ctrl + enter Print version