A special stretch of genetic material may turn off the immune suppression that stymies attempts to fight cancer with a vaccine, said researchers at Baylor College of Medicine (BCM) at Houston.
In a report in today's issue of the journal Science, Dr. Rong-Fu Wang, a professor in the BCM Center for Cell and Gene Therapy and Department of Immunology, and his colleagues describe a new strategy to turn off the function of a special group of T cells to suppress immune response to tumors and even infectious diseases.
"Since 1995, many groups have tried to develop a vaccine for the treatment of cancer," said Wang, also a member of the faculty of the BCM Graduate School of Biomedical Sciences. "The only problem is that after 10 years of clinical trials, the data suggest that you can induce (cancer) antigen-specific immune responses, but such responses are too weak and transient to eradicate tumor cells."
The answer lies in a group of cells called CD4+ regulatory T cells (Treg for short). These cells have the ability to suppress the body's natural immune response. If they are depleted, autoimmune diseases will result because the immune system is unchecked and goes on to attack the body's own tissues.
His group previously reported the existence of tumor-specific Treg cells at tumor sites. "Thus, the tumor cells use these Treg cells to protect themselves," said Wang. "In fact, tumor cells can actively recruit and activate them to turn on their immune suppressive function."
One way to stop this action is to simply wipe out the cells with chemoagents or a specific antibody.