THIS IS A SHANNON AWARD PROVIDING PARTIAL SUPPORT FOR THE RESEARCH PROJECTS THAT FALL SHORT OF THE ASSIGNED INSTITUTE'S FUNDING RANGE BUT ARE IN THE MARGIN OF EXCELLENCE. THE SHANNON AWARD IS INTENDED TO PROVIDE SUPPORT TO TEST THE FEASIBILITY OF THE APPROACH; DEVELOP FURTHER TESTS AND REFINE RESEARCH TECHNIQUES; PERFORM SECONDARY ANALYSIS OR AVAILABLE DATA SETS; OR CONDUCT DISCRETE PROJECTS THAT CAN DEMONSTRATE THE PI'S RESEARCH CAPABILITIES OR LEND ADDITIONAL WEIGHT TO AN ALREADY MERITORIOUS APPLICATION. THE ABSTRACT BELOW IS TAKEN FROM THE ORIGINAL DOCUMENT SUBMITTED BY THE PRINCIPAL INVESTIGATOR. DESCRIPTION (Adapted from the Applicant's Abstract): The long term goal of this project is to develop tumor-specific immunotherapeutic approaches. This project aims to identify the antigens which yield specific peptide/MHC class I and class II complexes recognized by tumor- specific T-lymphocytes. Almost all presently known tumor genes are identical to self-proteins expressed in the target or other normal tissue. Because these antigens elicit CD8+ T-cells, it raised critical issues on how immune tolerance is maintained, and their potential usefulness in immunotherapy. Identifying the antigen genes in the murine EL-4 thymoma will extend knowledge of these antigens in the T-cell lineage. Furthermore, because T-cells are present during negative selection in the thymus, tolerance to normal T-cell antigens is expected to be stringent and therefore T-cell stimulating antigens expressed by thymoma are expected to yield novel antigenic peptides. Unique reagents and techniques developed in the principal investigator's laboratory will be used to overcome inherent difficulties in the analysis of rare antigenic peptides or transcripts. These include, single T-cell assays for peptide/MHC epitope and efficient generation of peptide/MHC ligands in antigen presenting cells. Together, these methods have been used to identify rare peptide/MHC class I and II complexes recognized by CD8+ and CD4+ T-cells specific for antigens involved in transplantation and bacterial pathogenesis. These methods will be used to (1) generate lacZ inducible, CD8+ and CD4+ T-cells specific for the EL-4 T- cell tumor, that will be used to (2) isolate the donor antigen encoding cDNA clones, (3) The genes encoding the antigenic peptides will be identified in the cloned cDNAs, and (4) the pattern of gene expression will be determined in a panel of tumor and normal tissue. In aim 5 the isolated antigen genes and peptides will be tested for efficacy in eliciting tumor specific immunity and in tumor rejection. The identified antigen genes in T-cell tumors, in addition to serving as diagnostic and therapeutic reagents, will also be a tool for testing the current hypotheses of immune tolerance and surveillance.