In recent years, researchers have worked to develop a number of vaccines to help the immune system fight tumors. Cancer vaccines are not intended to prevent cancer; rather, they are used to boost immune responses to preexisting tumors.
Unlike traditional chemotherapy, vaccines have relatively low toxicity and, potentially, a high degree of efficacy.
To date, these vaccines have rarely been designed to directly stimulate one of the body’s most critical immune responders, the helper T cells. Though helper T cells contain receptors on their cell surfaces that are capable of recognizing and binding to tumor-related antigens, scientists have been stymied by the complex and time-consuming process required to isolate and clone the antigens for vaccine development.
In working to identify a key tumor antigen in melanoma and other cancers, scientists at The Wistar Institute have now developed a novel way to clone an antigen recognized by a helper T cell. Already, Herlyn’s group has used the new cloning technique to identify a new tumor antigen called ribosomal protein L8, or RPL8. Findings on the new cloning method and the newly identified tumor antigen will be published as a Priority Report in the April 15 issue of Cancer Research.
The new antigen-cloning approach may allow scientists to design vaccines capable of directly stimulating helper T cells, aiding the development of vaccines not only for cancer but also for infectious diseases, says Dorothee Herlyn, D.V.M., senior author on the study and a professor in the Molecular and Cellular Oncogenesis and Immunology programs at Wistar.
“Most of the melanoma vaccines currently in development work to activate a type of white blood cell called cytotoxic T-lymphocytes, or CTL,” says Herlyn. “Though CTL have the ability to destroy cancer cells, they don’t have the ability to call upon the full capabilities of the immune system, as do the helper T cells.”