The broad and long-term objectives of this proposal are: (1) the development of effective immunotherapeutic strategies against human melanoma; and (2) the identification of potent anti-tumor effector T cells. Our hypothesis is that pre-effector cells against autologous melanoma may be induced in the draining lymph nodes by active specific immunotherapy. However, these pre-effector cells may not be active unless they become activated in vitro to become effector cells. This study is meant to induce specific pre-effector cells in vivo by active specific immunotherapy and to activate and expand these pre-effector cells in vitro to become anti-tumor effector cells for adoptive immunotherapy.
The specific aims are: (1) to study the immune response of patients undergoing T cell immunotherapy; (2) to study mechanisms of GM-CSF as an immune adjuvant sensitizing lymph node T cells in vivo with special attention to the role of antigen-presenting cells; and (3) to correlate between immunologic characteristics and in vitro reactivities of lymph node T cells with their in vivo anti-tumor efficacy. Stage IV melanoma patients will be immunized with irradiated autologous tumor ells mixed with GM-CSF as an adjuvant to boost the immune response. Tumor vaccine draining lymph nodes harvested surgically 7 days later will be activated and expanded in vitro with a bacterial super- antigen followed by anti-CD3. A large number of these activated T cells will be infused intravenously to the patient for adoptive immunotherapy. In this research-driven clinical trial, immunological characteristics of these activated T cells will be studied in detail using ELISA and ELISPOT for cytokine production, 51/chromium release assay for T cell cytotoxicity, flow cytometry and immunohistochemical staining for T cell markers and polymerase chain reactions for T cell receptor usage. Skin tests will be performed and analyzed. The in vitro reactivities of these cells will be correlated with their in vivo anti-tumor efficacy and skin test reactivity. It is hoped that this study will allow us to have a better understanding of host-tumor interactions and to improve methods for the generation of therapeutically potent effector T cells. If the criteria to generate specific T cells against autologous melanoma can be established, the health relatedness of the project is a significant therapeutic breakthrough for patients with metastatic melanoma as there is no effective treatment for these patients to date.
