Emerging concepts in biomarker discovery; The US-Japan workshop on immunological molecular markers in oncology

Supported by the Office of International Affairs, National Cancer Institute (NCI), the "US-Japan Workshop on Immunological Biomarkers in Oncology" was held in March 2009. The workshop was related to a task force launched by the International Society for the Biological Therapy of Cancer (iSBTc) and the United States Food and Drug Administration (FDA) to identify strategies for biomarker discovery and validation in the field of biotherapy. The effort will culminate on October 28th 2009 in the "iSBTc-FDA-NCI Workshop on Prognostic and Predictive Immunologic Biomarkers in Cancer", which will be held in Washington DC in association with the Annual Meeting. The purposes of the US-Japan workshop were a) to discuss novel approaches to enhance the discovery of predictive and/or prognostic markers in cancer immunotherapy; b) to define the state of the science in biomarker discovery and validation. The participation of Japanese and US scientists provided the opportunity to identify shared or discordant themes across the distinct immune genetic background and the diverse prevalence of disease between the two Nations

Tumor-infiltrating DCs suppress nucleic acid-mediated innate immune responses through interactions between the receptor TIM-3 and the alarmin HMGB1

The mechanisms by which tumor microenvironments modulate nucleic acid-mediated innate immunity remain unknown. Here, we identified the receptor TIM-3 as key to circumventing the stimulatory effects of nucleic acids in tumor immunity. TIM-3 is highly expressed on tumor-associated dendritic cells (DC) in murine tumors and cancer patients. DC-derived TIM-3 suppresses innate immune responses through Toll-like receptor and cytosolic sensor recognition of nucleic acids via a galectin-9 independent mechanism. Instead, TIM-3 interacts with the HMGB1 to interfere with recruitment of nucleic acids into DC endosomes and attenuates the therapeutic efficacy of DNA vaccination and chemotherapy by reducing immunogenicity of nucleic acids released from dying tumor cells. Together, these findings define a novel mechanism by which tumor microenvironments suppress antitumor immunity mediated by nucleic acids