Research directions
Human Tumor Immunology and Immune Therapy
Recent progress in molecular and cellular immunology provide the basis and the reagents to address scientific questions in cancer patients. Animal models have convincingly shown that CD8+ T lymphocytes can protect from tumor progression, and this issue is now systematically addressed in humans. A central step was the identification of human tumor antigens encoding epitopes recognized by CD8+ T cells. Another important finding was the identification of spontaneous tumor antigen specific T cell responses in melanoma lesions, clearly demonstrating that tumor cells and CD8+ T cells interact in an antigen specific manner, comparable to immunity in infectious diseases. However, tumor specific immunity does usually not protect from disease progression. Many immune escape mechanisms have been described that may explain why tumor cells do not interact more intensively with lymphocytes. Such mechanisms are for example somatic mutations or reduced expression of antigens or MHC molecules by tumor cells. Alternatively, the cytolytic activity of human T cells against tumor cells may be inhibited upon triggering of natural killer inhibitory receptors
Research activities
We are specialized for clinical investigation of cancer patients and analyze immunity against malignant melanoma and colon cancer cells. Tumor cells are investigated at the level of tumor antigen expression. Lymphocytes are evaluated with respect to their ability to specifically recognize tumor cells. The degree of lymphocyte activation, and the strength of interaction with tumor cells is measured since this correlates with protective potential against tumor cell growth
We perform phase I clinical trials of vaccination with antigenic peptides and adjuvants in patients with advanced malignant melanoma. The goals of these trials are to test the safety of these vaccines and their ability to induce a tumor specific CD8+ T cell response. We perform these trials in collaboration with oncologists at the Centre Pluridisciplinaire d'Oncologie, CHUV, headed by Prof. Ferdy Lejeune
