Researchers at both institutions report in today's issue of Science that blocking the activation of a regulator of inflammation called tumor necrosis factor (TNF) decreased swelling by 25 percent in a rodent model of the human disease rheumatoid arthritis. Elevated TNF levels are associated with the onset of rheumatoid arthritis.
The uniqueness of the new inhibitors, the scientific team reports, lies in their design and mode of action. Unlike the drugs that are currently available, the structure and sequence of these newly designed molecules are similar to naturally produced proteins, making it less likely that the body will elicit an immune response to fight off foreign agents.
"What we've engineered are variant proteins that are very similar to the protein that the body expresses on its own, which makes it less likely that the body will see it as foreign," said Dr. Mal Tansey, a lead author of the study and assistant professor of physiology at UT Southwestern, where some of the in vivo testing and validation was completed and where work will continue on these TNF inhibitors.
"The inhibitors are actually modified versions of the TNF protein that is naturally found in the body, but with a few mutations that prevent them from binding to receptors but still allow the proteins to bind TNF. The end result is sequestration of active TNF away from the receptors that mediate inflammatory responses implicated in rheumatoid arthritis and several other autoimmune diseases," said Dr. Tansey, former member of the Xencor team.