ESCII-PIVAC meeting "Recent advances in cancer immunotherapy with an emphasis on cancer vaccines" held in Athens, 9-11 October 2008.

Abstract

The conference “Recent advances in cancer immunotherapy with an emphasis on vaccines” was organized by the European Society of Cancer Immunology and Immunotherapy (ESCII) and Progress in Vaccination against Cancer (PIVAC) represented by G. Forni, Turin, Italy; R. Kiessling, Stockholm, Sweden; C. Melief, Leiden, The Netherlands; G. Pawelec, Tubingen, Germany; and M. Papamichail, Athens, Greece. The main aims were to review the state of the art of cancer vaccination using diVerent approaches and the role of various eVector and regulatory immune cells both in animal tumour models and in cancer patients. This report provides a short overview of novel concepts, strategies and clinical developments in the Weld following the Wrst ESCII meeting held also in Athens in 2007. About 150 participants from 17 countries of Europe, Asia, North and South America were attracted by the scientiWc program that consisted of presentations from 37 international experts. Good memories remain not only from the lively discussions of six scientiWc sessions and 40 posters, but also from the beauty of ancient Athens and the social evenings in the down-town with local food and drinks. The Wrst session was opened with a presentation from O. Finn (Pittsburgh, USA) who proposed the concept of abnormal self antigens as a group of tumour associated antigens and emphasized their role in cancer surveillance. Abnormal self antigens (MUC-1 and Cyclin B1 proteins were taken as examples) can also be expressed in nonmalignant situations such as bacterial and viral infections. They induce memory responses and can be a part of the “natural” cancer immune surveillance. Finally, these antigens are immunogenic and safe, and can be used in the vaccination of tumours. C. Baxevanis (Athens, Greece) presented a broad overview of the modern knowledge on the role of CD4 T lymphocytes, as cells orchestrating immune responses in the tumour bearing host. Among them are “eVectors” (Th1 and Th2 cells) and “regulators” [Th17, Natural Killer T (NKT) and regulatory T (Treg) cells]. Interestingly, only Th1 could be considered as strictly promoting and Treg as strictly inhibiting immune responses against tumours, pathogens or self antigens. Thus, Th1 cells play a central role in anti-tumour immunity by mediating direct tumour killing, activating innate mechanisms and improving CTL responses. Th17 cells from TRP-1 TCR transgenic mice can eradicate established B16 melanomas. Several technological improvements have been made to enhance the immunogenicity of MHC class II vaccine approaches. To this end a novel technique has been developed whereby the Ii-Key segment of the immunoregulatory Ii protein is coupled to MHC class II epitopes. The Ii-Key segment catalyzes the binding of the epitope to MHC class II molecules and thereby enhances the potency of the vaccine. While some NKT cells are able to induce immune responses, others can suppress immunity. An importance of invariant NKT cells for tumour immunotherapy was emphasised by V. Cerundolo (Oxford, UK). These cells can be stimulated directly by dendritic cells (DCs) via TLR signalling or indirectly through IL-12 and IL-18. Interestingly, activated invariant NKT cells may abolish immunosuppressive activity of myeloid derived suppressor cells (MDSC) V. Umansky (&) Clinical Cooperation Unit, Dermato-Oncology (G300), German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany e-mail: V.Umansky@dkfz-heidelberg.de