Vaccine-style treatment for rheumatoid arthritis retrains the immune system

 

Research led by Professor Ranjeny Thomas has uncovered a promising new approach to preventing rheumatoid arthritis According to the American College of Rheumatology, more than one million US citizens suffer from rheumatoid arthritis. The disease gives rise to swelling and pain by causing the immune system to malfunction and attack healthy tissue. No cure is available, though aggressive and varied drug treatments can curb its effects. Now, success in an early clinical trial suggests that a new form of therapy could stop these symptoms taking hold by retraining the patient's immune system to ignore a peptide it normally identifies as a foreign foe. Normally, our immune cells trawl through our blood and tissue, sorting foreign matter from healthy tissue to fight off signs of infection. Rheumatoid arthritis takes effect when these immune cells incorrectly identify healthy cells as foreign and attack them instead. Rather than looking at ways to treat the effects once this chain of events has already played out, researchers from Australia's University of Queensland looked to zero in on the root cause. Led by Professor Ranjeny Thomas, the team developed a vaccine-style therapeutic approach, or immunotherapy, for people with the most common form of rheumatoid arthritis, known as CCP-positive. The treatment is designed to re-educate the body's immune system to leave certain naturally occurring peptides alone, therefore preventing inflammation. To accomplish this, immune cells known as dendritic cells are extracted from the body and mixed with an anti-inflammatory drug and a natural peptide found in arthritic joints, before being injected back into the body once again. "The dendritic cells are educators of the immune system," Thomas explains to Gizmag. "They show peptides to the immune system and the T lymphocytes (student soldiers) then get the message to either attack or do a peace-keeping mission for that peptide. When we deliver peptide and an anti-inflammatory drug to a dendritic cell, it teaches the T lymphocytes to keep the peace in that tissue, thus keeping it healthy." In its current state, the treatment is too expensive and time-consuming to see it adopted for widespread use. But Thomas says the study's results, which indicate a single injection of the immune-modified dendritic cells can help suppress the effects of rheumatoid arthritis, are promising enough to continue development of more practical versions of the therapy, such as using nanoparticles as a delivery mechanism. "We can use a nanoparticle to package the drug and the peptide," she says. "After injection, the nanoparticle finds the dendritic cells and delivers the payload to them in the body. So far this has been tested in animal models but we plan to test in RA (rheumatoid arthritis) patients in 2016." If the approach is proven successful for sufferers of rheumatoid arthritis, it could potentially be used to treat other autoimmune diseases, such as Type 1 diabetes and and multiple sclerosis. The research findings were published in the journal Science Translational Medicine.   Source: University of Queensland