Cancer vaccines are not intended to prevent cancer; rather they are used to boost immune responses to pre-existing tumors, scientists at the Wistar Institute in Philadelphia said.

To date, such vaccines have rarely been designed to directly stimulate one of the body's most critical immune responders, the helper T cells. Although helper T cells contain receptors on their cell surfaces 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.

Now Wistar researchers working to identify a key tumor antigen in melanoma and other cancers have developed a novel way to clone an antigen recognized by a helper T cell. Led by Dr. Dorothee Herlyn, the researchers have used the cloning technique to identify a new tumor antigen called ribosomal protein L8.

Findings on the new cloning method and the newly identified tumor antigen are reported in the current issue of the journal Cancer Research.