I am working to understand and manipulate mechanisms of tumor-induced immune suppression to achieve more potent immune-based therapies. In particular, I have been studying how costimulatory molecules differentially affect Tregs and T effector cells in the tumor microenvironment. Engaging costimulatory molecules by in situ gene transfer or using monoclonal antibodies have shown efficacy in eradicating established tumors in mouse models particularly when combined with DNA vaccines and conventional chemotherapies. In addition, I have been developing new generations of DNA vaccines based on targeting tumor antigens to APCs in order to generate more potent anti-tumor immunity.