Tumors are complex ecosystems containing not just cancer cells, but a large variety of cell types, including immune cells. Moreover, tumors have a systemic influence: they can signal long distances... Show moreTumors are complex ecosystems containing not just cancer cells, but a large variety of cell types, including immune cells. Moreover, tumors have a systemic influence: they can signal long distances using soluble molecules and hijack non-neoplastic cells (such as immune cells) in distant organs for their own benefit, thus maximising their metastatic potential. The phenotype of immune cells in tumors and in systemic environments is therefore a key determinant of cancer progression and response to therapy.This thesis aims to understand what governs the tumor-immune ecosystem. We argue that cancer-intrinsic genetic aberrations have a dominant role in determining the tumor immune contexture, as well as systemic inflammatory activation. Understanding the intricate connection between the genetics of breast cancer and anti-tumor immune responses will help develop personalised immune intervention strategies for cancer, tailored to the genetic makeup of a patient’s tumor. Furthermore, we examine in detail the role of neutrophils in cancer-induced systemic inflammation, and how they influence the progression and spread of breast cancer. While tumors can be highly heterogeneous in nature, we show that neutrophils themselves also have a tremendous phenotypic diversity. Mapping this heterogeneity in neutrophil phenotypes may help to utilise these cells in cancer immunotherapy. Show less
My PhD studies focused on understanding the role of macrophages, a type of immune cells which are abundantly present in several tumor types, in breast cancer progression and therapy response.In the... Show moreMy PhD studies focused on understanding the role of macrophages, a type of immune cells which are abundantly present in several tumor types, in breast cancer progression and therapy response.In the first part of my thesis, I describe how macrophages can acquire different functional characteristics in different types of breast cancer. Next, I focused on understanding the interplay between macrophages and cancer therapies. In particular, I revealed that macrophages counteract the efficacy of conventional chemotherapy drugs. I showed that eliminating macrophages with an antibody that targets CSF-1 receptor (CSF-1R) enhances the anti-cancer efficacy of platinum-based chemotherapeutic agents in breast cancer. I mechanistically discovered that CSF-1R inhibition stimulates intratumoral type I interferon signaling which is essential for the therapeutic synergy between cisplatin and CSF-1R blockade. I also uncovered that further elimination of immunosuppressive neutrophils, another type of immune cells, was required to engage an efficacious anti-tumor immunity. Show less
