Use of Expression Cloning to Identify Novel Antigens Recognized on Human Prostate Tumors to Act as Targets of Cellular Immunotherapy

摘要

Our aim is to identify epitopes on the surface of prostate cells that are largely or exclusively tissue- or tumor-specific. This is done by expansion of T cells reactive for HLA-restricted, established tumor lines from the peripheral blood cells and tumor-infiltrating lymphocytes of cancer patients. Towards this end, we established a reagent bank of patient material that includes tissue, cells, and serum. We successfully and stably gene-modified the established prostate cell line, LNCaP, so that it expresses HLA-A2 and HLA-A1. We successfully transfected two other cell lines with these genes, transiently but sufficiently, for our in vitro stimulation technique. Several potentially HLA-restricted, tumor-specific T cells have been identified and are currently being cultured by methods developed in our laboratory. In addition, we are performing an antibody-based method of antigen discovery that utilizes patient serum. Using this approach, several genes have been identified, some of which represent previously unreported, novel genes. Studies are underway to discern the exact epitope being recognized. Studies are also underway to assess the level of gene expression in normal vs tumor tissue from representative regions of the body.