Cancer Immunity 3:12 (2003)

Disease-driven T cell activation predicts immune responses to vaccination against melanoma

Daniel E. Speiser¹, Donata Rimoldi², Pascal Batard¹, Danielle Liénard^1,3, Ferdy Lejeune³, Jean-Charles Cerottini², and Pedro Romero^1,2

¹Division of Clinical Onco-Immunology, Ludwig Institute for Cancer Research, Lausanne Branch, University Hospital (CHUV), Lausanne, Switzerland
²Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, Epalinges, Switzerland
³Multidisciplinary Oncology Center, University Hospital, Lausanne, Switzerland

Keywords: human, melanoma, vaccination, Melan-A peptide, immunological monitoring, cytotoxic T cells

Abstract

Tumor vaccines may induce activation and expansion of specific CD8 T cells which can subsequently destroy tumor cells in cancer patients. This phenomenon can be observed in approximately 5-20% of vaccinated melanoma patients. We searched for factors associated with T cell responsiveness to peptide vaccines. Peptide antigen-specific T cells were quantified and characterized ex vivo before and after vaccination. T cell responses occurred primarily in patients with T cells that were already pre-activated before vaccination. Thus, peptide vaccines can efficiently boost CD8 T cells that are pre-activated by endogenous tumor antigen. Our results identify a new state of T cell responsiveness and help to explain and predict tumor vaccine efficacy.