August 11, 2003
The development of custom treatments for autoimmune diseased mice could lead to DNA vaccines for treating such conditions as multiple sclerosis, rheumatoid arthritis and type 1 diabetes.
Researchers from Stanford University Medical Center in California have used DNA microarray technology to genetically identify and treat mice with a disease similar to multiple sclerosis.
The team took blood samples from mice with experimental autoimmune encephalomyelitis, in which the immune system -- as it does in multiple sclerosis -- attacks the neuron-insulating myelin sheath, leading to a number of neurological disorders.
After analyzing blood samples from the mice using DNA microarrays, the researchers developed individualized treatments to reduce disease progression.
Working from the knowledge that autoimmune responses develop when antibodies mistakenly build up against proteins in organs, the researchers pursued a therapy called tolerization that targets harmful immune processes while leaving the immune system functional.
As the term suggests, tolerization teaches the immune system to tolerate a protein by exposing it to a protein or pieces of it.
The process is similar to injecting allergens into muscles to diminish allergy symptoms.
In this case, the researchers used microarray information to guide them in choosing appropriate protein targets.
To create a DNA vaccine, they used a protein-encoded piece of DNA called a plasmid.
The advantage of the vaccine is that it can tolerize multiple autoimmune targets simultaneously, rather than one at a time.
"We found that this approach broadly turns off autoimmune responses," says Bill Robinson, the study's lead author. "Clinically, the animals do better when receiving the vaccine. When we use our arrays to monitor the response, we see broad reductions in the progression of the disease."
Besides vaccine development, the researchers' microarray technique could also be a better method for diagnosing people with autoimmune diseases.
"It would be great to have a test that would let us know if a person is going to have a horrible outcome so we could treat aggressively, or if a person is going to be fine, or if a person is going to have a bad response to a therapy so we could avoid that," says Robinson.
To implement such testing, the researchers have cofounded a company called Bayhill Therapeutics.
Their study will be published in the September issue of Nature Biotechnology
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