My research focuses on understanding host:tumor interactions through the study of cancer immunotherapy. Specifically, my projects involve the development and testing of cancer vaccines and T cell therapies from preclinical testing to human clinical trials. We initially studied the conditions necessary to activate high frequency T cell and antibody responses against cancers. We observed that immune responses against cancer antigens were frequently blunted despite continued immunizations and identified tumor-mediated immunomodulation through regulatory T cells and vascular endothelial growth factor as contributing factors. Subsequently, we studied methods to eliminate regulatory T cells and to ameliorate the immunoinhibitory effects of vascular endothelial growth factor as ways to enhance the efficacy of immunizations. Recently, we have also been studying the ability of receptor tyrosine kinase inhibitors to synergize with or enhance the immune- mediated killing of tumors. In addition, we have been studying the functional activity of polyclonal antibody sera activated by cancer vaccines. We have identified antibody responses against molecules such as HER2 to have anti-signaling activity in addition to classical immune effects such as antibody-dependent cellular cytotoxicity.