Abstract A160: Deep immunoprofiling of mouse lung cancer models in steady state and upon drug treatment.

With the advancement of immunotherapies for lung cancer, it has become apparent how insufficient our knowledge is surrounding the interactions between the tumor and the immune system. In particular in the context of combining immunotherapy with conventional chemotherapy or novel targeted therapies, it is of the utmost importance that we understand the effects that those therapies have on the tumor immune infiltrate and how that would counteract or synergize with immunotherapy. We have used multiplex flow cytometry to characterise the basal tumor immune infiltrate of various spontaneous and orthogonous syngeneic mouse models for lung cancer, with different levels of immunogenicity. With imaging mass cytometry, visualizing and quantifying >30 markers simultaneously in mouse tumor tissue sections, we studied the localization and interactions of the immune cells within and surrounding the tumors. This has highlighted the level to which tumors are regulating their microenvironment, actively excluding all potential effector cells while attracting protumoral myeloid cells, and how this is amplified as the tumors progress. We have observed differences between the various models and seen how the tumors make adaptations when they are intrinsically more immunogenic. Furthermore, we have started to address how these balances are perturbed by various immune and chemotherapies in short- and long-term experiments and preliminary data will be presented. Citation Format: Febe van Maldegem, Karishma Valand, Victoria Tsang, Edurne Mugarza, Deborah Caswell, Philip Hobson, Julian Downward. Deep immunoprofiling of mouse lung cancer models in steady state and upon drug treatment. [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A160.