Antigen-Specific Cancer Vaccines

Advances in basic immunology over the past decade have changed the scope and application of cancer vaccines. Perhaps the most important advance is the demonstration that human tumors are immunogenic and the identification of tumor-specific antigens. In fact, dozens of immunogenic proteins have been identified in patients with cancer using high throughput technologies. More importantly, we have begun to identify proteins that are immunogenic in cancer whose function may be a causal component in the malignant transformation. Thus, cancer vaccines targeting these biologically relevant antigens may result in the eradication of tumor cell clones that drive the initiation of malignancy. The roles of the immune and tumor microenvironments in cancer greatly influence our approach to the design of antigenspecific cancer vaccines. Stimulation of both cytotoxic T-cell and CD4 T helper cell immunity is critically important for an effective antitumor response. Furthermore, the identification of the dendritic cell and the understanding of its role in initiating immunity to cancer has not only led to the development of novel vaccine strategies but has focused attention on the major role of the antigen-presenting cell in initiation of the tumor-specific immune response. Finally, the clinical application of cancer vaccines is changing. Vaccines that target tumor antigens are increasingly being viewed and studied as chemopreventive agents designed to protect against cancer relapse or development. IDENTIFICATION OF SPECIFIC TUMOR