Peptide-based tumor vaccines

Introduction Several specific tumor antigens have been defined by virtue of their immunogenicity in cancer patient5 [1,2]. In addition to the definition of specific tumor antigens, we now understand that T-cells recognize those antigens as peptides presented in the context of human major histocompatibility (MHC) molecules. These basic ob5ervatioJ15 have generated interest in the design of tumor antigen-specific, peptide­ based vaccines. The use of synthetic peptides as cancer vaccines offers practical advantages, relative ease of construction and production, chemical stability and a lack of infectious or oncogenic potential [3]. Peptides may also allow better manipulation of the inunune response through the use of epitopes designed for stimulating particular subsets of T-cells. Most importantly, peptide vaccines appear to be effective in generating immune responses to autologous proteins [4-]. T-cells may be tolerant to the dominant peptide epitopes of autologous proteins but may respond to subdominant peptide epitopes [5,6"1· As many newly-defined tumor antigen.<; are autologous proteins [7], peptide immunization may playa key role in the ability to elicit an immune response to these antigens.