Immune system depressant prevents rheumatoid arthritis in mice

Washington, Feb 9: Scientists from Dana-Farber Cancer Institute have demonstrated a new strategy for treating autoimmune disease that successfully blocked the development of rheumatoid arthritis in a mouse.

They said that it holds promise for improved treatment of arthritis and other autoimmune disorders in people.

The scientists report that infusing a highly specific type of cell that regulates immune responses into arthritis-prone mice shut down the cascade of inflammation that damages tissues and joints.

The method worked best when the infusions of CD8+ Treg cells were given at the same time that the animals were injected with a protein that triggered the arthritis-causing autoimmune reaction.

“We found we could almost completely inhibit the disease in this setting,” Harvey Cantor, MD, chair of the Department of Cancer Immunology and AIDS at Dana-Farber and the study’s senior author said.

Even when administered weeks after the disease was initiated, CD8+ Treg infusions combined with low doses of methotrexate – a commonly used drug for rheumatoid arthritis – were able to significantly slow the arthritis process, the scientists said.

The new strategy also blocked disease progression when the scientists injected peptide antigens to expand the rodents’ own pool of CD8+ Tregs, rather than infusing them from outside.

Overall, the results “suggest that [these] strategies represent a promising therapeutic approach to autoimmune disorders,” the researchers wrote.

Moving closer to clinical relevance, the researchers will test this approach in mice carrying human immune cells that provoke an autoimmune response.

Cantor said they are also studying the possibility of using nanoparticles coated with Qa-1/Hsp60 molecules to expand CD8+ Tregs as a more practical method that might be used someday for human therapeutic tests.

The findings are published in the Journal of Clinical Investigation. (ANI)