Abstract IA07: Impact of tumor-resident dendritic cells on antitumor immune responses

Abstract

Abstract The responsiveness of tumor towards checkpoint blockade therapy but also other immunotherapies is highly associated with the presence of CD8+ infiltrating T cells. Further, an increasing amount of recent studies revealed a critical role for cross-presenting CD103+ dendritic cells (DC1) in both the induction and maintenance of CD8+ T-cell immunity in the tumor. We have shown that exclusion of DC1 from the tumor microenvironment (TME) can result in both blunted T-cell priming and impaired recruitment of effector T cells into the TME. Thus, exclusion of DC1 represents a mechanism of immune evasion by the tumor and resistance towards immunotherapy. Therefore, elucidating the contributions of different DC subsets to the local tumor microenvironment will be instrumental for the improvement of current immunotherapies. In more recent data we compare models of strong and poor antitumor immune responses with a specific focus on tumor-resident dendritic cells. These experiments reveal the absence of several immune-potentiating dendritic cell subsets in tumors with impaired antitumor immunity. Citation Format: Stefani Spranger. Impact of tumor-resident dendritic cells on antitumor immune responses [abstract]. In: Proceedings of the AACR Special Conference on Melanoma: From Biology to Target; 2019 Jan 15-18; Houston, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(19 Suppl):Abstract nr IA07.