Feb. 24 (UPI) -- Researchers at The Wistar Institute in Philadelphia and Inovio Pharmaceuticals have devised a new DNA vaccine approach to improve anti-tumor immunity in cancer patients.
Immunotherapy treatments are designed to use the body's natural immune defenses to target and kill cancer cells. DNA vaccines can induce immunity through the delivery of a sequence of synthetically designed DNA that contains instructions for immune cells to target a specific cancer antigen.
The identification of tumor-associated antigens, or proteins that are expressed by tumor cells and not by normal cells, has led to the development of DNA vaccines as a potential new way to target cancer tumors.
However, most vaccines targeting tumor-associated antigens have had little success in fighting cancer due to poor immunogenicity. Tumor-associated antigens trigger weak immune responses because they are recognized as self-antigens, and the body prevents autoimmunity through natural immune responses that limit the efficacy of cancer vaccines.
The Wilm's tumor gene 1, or WT1, is a tumor antigen that is over-expressed in many forms of cancer and plays a vital role in tumor development.
Researchers at The Wistar Institute created a new WT1 DNA vaccine using a strategically-modified DNA sequence that identifies the WT1 as foreign to the host immune system, disrupting tolerance in animal models.
"This is an important time in the development of anti-cancer immune therapy approaches," David B. Weiner, Ph.D., executive vice president and director of the Vaccine Center at The Wistar Institute, the W.W. Smith Charitable Trust Professor in Cancer Research and senior author of the study, said in a press release. "This team has developed an approach that may play an important role in generating improved immunity to WT1 expressing cancers. These immune responses represent a unique tool for potentially treating patients with multiple forms of cancer. Our vaccine also provides an opportunity to combine this approach with another immune therapy approach, checkpoint inhibitors, to maximize possible immune therapy impact on specific cancers."
The new WT1 vaccine was more effective than a more traditional WT1 vaccine because it can break immune tolerance and induce long-term immune memory.
The study was published in Molecular Therapy.