Generation of cellular immune responses to antigenic tumor peptides

Tumor immunotherapy is currently receiving close scrutiny. However, with th e identification of tumor antigens and their production by recombinant mean s, the use of cytokines and knowledge of major histocompatibility complex ( MHC) class I and class II presentation has provided ample reagents for use and clear indications of how they should be used. At this time, much attent ion is focused on using peptides to be presented by MHC class I molecules t o both induce and be targets for CD8(+) cytolytic T cells. Many peptides ge nerated endogenously or given exogenously can enter the class I pathway, bu t a number of other methods of entering this pathway are also known and are discussed in detail herein. While the review concentrates on inducing cyto toxic T cells (CTLs), it is becoming increasingly apparent that other modes of immunotherapy would be desirable, such as class II presentation to indu ce increased helper activity (for CTL), but also activating macrophages to be effective against tumor cells.