Off Switch on Disease

Dr Thomas studies dendritic cells

A University of Queensland team at the Princess Alexandra Hospital is believed to be the first in the world to find a mechanism to turn off an auto-immune disease once it has started.

The discovery by a University of Queensland team of a way to "turn off" auto-immune diseases provides a possible basis for a vaccine against diseases, including rheumatoid arthritis and juvenile diabetes, where the body's immune system inappropriately attacks healthy cells.

The work, which is still at the preliminary stages, also has implications for treating allergic diseases such as asthma, and making allografts, the grafting of tissue from one individual to another of the same species, safer.

A commercially available vaccine is several years away, with human clinical trials yet to be held.

The UQ Centre for Immunology and Cancer Research team at Princess Alexandra Hospital found a molecular control mechanism to re-educate the immune system.

It's not a new idea to re-educate the immune system," said rheumatologist and Centre Deputy Director Associate Professor Ranjeny Thomas.

"What's different is that this is the first time it has been possible to suppress an existing response once the immune system has started down a deleterious pathway."

Dr Thomas and her team made the discovery while working on dendritic cells ? potent, antigen-presenting cells with the unique capacity to prime the immune response.

Many research groups internationally are exploring the properties of the cells, with different scientific approaches. Dendritic cells are found in lymphoid organs as well as nonlymphoid tissues, including the skin, joints and circulating blood.

Dr Thomas said suppression of a previously primed immune response was a major challenge for immunotherapy of auto-immune and allergic diseases.

The team achieved success by exploiting their understanding of the pathway controlling the interaction between dendritic cells and the immune system.

They turned off one of the key molecules in dendritic cells that feeds through to the T-cell immune response, and suppressed RelB activation in mouse and human dendritic cells, aiming to suppress or tolerise the immune system.

Preliminary findings suggest auto-immune diseases can be treated with dendritic cells to provide antigen-specific immune suppression.

Dr Thomas is internationally renowned for her work on dendritic cells in rheumatoid arthritis.

Her group at the Centre for Immunology and Cancer Research recently completed clinical trials using a dendritic cell vaccine for melanoma.

On this site