This study explored the possibilities of redirecting the immune system to generate an antitumor response. Tumor-associated antigens (TAAs) are not found on normal cells. TAAs associated with the tumor stroma are important, as immunity against TAAs could restrict tumor ability to metastasize and grow. Immunoediting refers to a process in which immune selection pressure favors growth of tumor cells. This occurs via alteration in antigen processing and presentation, production of immunosuppressive cytokines by tumor cells, and activation of immune-suppressive T-cell populations.
One of the most promising areas for clinical application is in the development of vaccines based on purified recombinant protein or nucleic acid TAAs. Vaccines reflect various strategies: Inactivated autologous or allogenic cancer cells, patient dendritic cells that have undergone in vitro stimulation, TAAs or proteins necessary for tumor progression, or recombinant vectors for antigen delivery. For instance, a vaccine against melanoma is based on immunization with DNA components of tyrosinase, a glycoprotein that synthesizes melanin. One way of increasing efficacy of antitumor vaccines is to add immunostimulatory molecules, such as interleukin-2 or a novel extracellular matrix vaccine adjuvant. Increased benefit often occurs when vaccines produced from harvested tumor material provide the broadest range of antigenic targets. Cancer immunotherapy is an exciting area of research that may provide treatment options with decreased potential for adverse effects, likely yielding productive data for both human and veterinary patients.