A special type of vaccination called “naked DNA” could hold the key to future treatment of autoimmune diseases such as rheumatoid arthritis. Scientists are hopeful that this exciting new technology may eventually treat and prevent rheumatoid arthritis.
The vaccine introduces genes into the body that have been engineered to mimic proinflammatory peptides, which consist of cytokines and chemokines. When the patient’s immune system sees these genes as foreign invaders, it produces its own neutralizing antibodies capable of restraining the disease.
Essentially, the process involves “teaching the immune system how to correct its own mistakes,” explains Dr. Nathan Karin of the Technion-Israel Institute of Technology. It does so by fooling the natural immune system into fighting itself by neutralizing the excessive inflammatory substances – cytokines and chemokines – it is producing.
“One way these (autoimmune) diseases could be controlled is by immunizing patients with neutralizing antibodies directed against one or more of the proinflammatory peptides,” said Karin.
There are, however, two key problems associated with using the neutralizing antibodies tested in the trials. First, they require frequent administration. Additionally, the body’s immune system eventually recognizes the antibodies as foreign and generates an immune response that can exacerbate the disease.
Karin believes that the new naked DNA vaccination technology can counter these negative effects. “Our laboratory has clearly shown that the major advantages of these self-generated antibodies lie not only in that they do not provoke an immune response, but also, and most importantly, in the ability they endow to the immune system to self-regulate their production in accordance with disease progression.
“This provides the immune system of a patient with an autoimmune disease with a powerful tool with which it can restrain its own harmful activities,” says the Technion scientist.
Karin’s laboratory has used the naked DNA technology to demonstrate that chemokine-based DNA vaccines can be used to both treat and prevent rheumatoid arthritis. The vaccine has so far only been tested on animals. In the next stage, Karin will continue exploring the vaccine using various vectors before testing it in humans. A paper on this technology appears in the August 1, 2000 issue of the Journal of Clinical Investigation.