Transient expansion of peptide-specific lymphocytes producing IFN-gamma after vaccination with dendritic cells pulsed with MAGE peptides in patients with mage-A1/A3-positive tumors

Assessment of T-cell activation is pivotal for evaluation of cancer immunot herapy. We initiated a clinical trial in patients with MAGE-A1 and/or -A3 t umors using autologous DC pulsed with MAGE peptides aimed at analyzing T-ce ll-derived, IFN-gamma secretion by cytokine flow cytometry and ELISPOT, We also tested whether further KLH addition could influence this response favo rably. Monocyte-derived DC were generated from leukapheresis products, They were pulsed with the relevant IMAGE peptide(s) alone in group A (n = 10 pt s) and additionally with KLH in group B (n=16 pts), A specific but transien t increase in the number of peripheral blood T lymphocytes secreting IFN-ga mma in response to the vaccine peptide(s) was observed in 6/8 patients of g roup A and in 6/16 patients of group B. We conclude that anti-tumor vaccina tion using DC pulsed with MAGE peptides induces a potent bat transient anti -MAGE, IFN-gamma secretion that is not influenced by the additional deliver y of a nonspecific, T-cell help.