Periodic Reporting for period 4 - TNT-TUMORS (Therapeutic approaches to enhance innate immunity against Tumors)
Berichtszeitraum: 2021-03-01 bis 2022-08-31
In the past decade the use of targeted therapies has led to an average gain in progression-free survival of only few months for cancer patients with advanced, refractory or metastatic disease indicating that there is an urgent need for novel therapeutic concept to cure cancer. A recent big breakthrough in cancer therapy has been the use of checkpoint inhibitors with significantly higher survival benefits for patients with metastatic disease. However, a large fraction of patients fails to respond to checkpoint blockades for reasons that are poorly understood. Moreover, effective biomarkers predicting response to immunotherapy are basically missing. It has long been recognized that cancer progression and therapy response strongly depend on the immune cell composition of the tumor microenvironment. Several strategies are currently being investigated to enhance immunogenicity of tumors and boosting T-cell mediated anti-tumor immunity. An alternative approach is to modulate innate immune cells.
Therefore, the major goal of TNT-TUMORS is to increase our understanding of the cellular and molecular mechanisms controlling the tumor-promoting characteristics of innate immune cells by focusing on plasmacytoid Dendritic cells (pDC) and myeloid cells/macrophages. Both these cell types infiltrate solid tumors and if properly modulated they may adopt anti-tumorigenic properties and enhance the effectiveness of current modern anti-cancer treatments. This project therefore aims at identifying new targets and strategies that prevent these cells from acquiring pro-tumorigenic functions and endow them with anti-tumorigenic properties with the final objective to identify novel therapeutic approaches to enhance innate immunity against tumors. Inducible and cell-specific genetic mouse models mimicking human cancers will allow to molecularly dissect the immunmodulatory capacity of pDCs and tumor-associated myeloid cells (TAMs). State-of-the-art large scale single cell sequencing and computational analyses provide a platform to identify novel molecular pathways and open the possibility for testing new strategies in cancer immunotherapy. The clinical significance of our findings will be validated in human cancer samples and a close cooperation with clinicians ensures a fast predictive and therapeutic translation of our results. A deeper understanding of these mechanisms will be of fundamental importance to develop more effective and possibly curative therapies aimed at treating tumors and, most essentially, metastatic disease.
In TNT-TUMORS we had proposed to employ genetically engineered mouse models (GEMMs) and patient material from melanoma, hepatocellular carcinoma (HCC) and colorectal cancer (CRC) as model tumors to study two types of innate immune cells, namely pDCs and myeloid cells/macrophages and find ways how to modulate them to attack tumor cells and to enhance the effect of standard anti-cancer therapies. We had previously identified two independent mechanisms by which modulation of pDCs and EGFR-positive myeloid cells (EGFR+ TAM) inhibited the growth of solid tumors. We had shown that stimulation of pDCs with TLR agonists could transform them into cells capable of directly killing tumor cells without the need of the adaptive immune system. Second, we identified a tumor-promoting role of EGFR+ TAMs during colorectal cancer (CRC) and hepatocellular carcinoma (HCC) formation. This enabled us to look at the role of EGFR in tumorigenesis in a completely different way as most of the previous studies had associated the oncogenic function of the EGFR to its expression in tumor cells. Thus, the mechanism by which anti-EGFR drugs are effective in tumors needs to be re-evaluated.
Therefore, the major goal of TNT-TUMORS is to increase our understanding of the cellular and molecular mechanisms controlling the tumor-promoting characteristics of innate immune cells by focusing on plasmacytoid Dendritic cells (pDC) and myeloid cells/macrophages. Both these cell types infiltrate solid tumors and if properly modulated they may adopt anti-tumorigenic properties and enhance the effectiveness of current modern anti-cancer treatments. This project therefore aims at identifying new targets and strategies that prevent these cells from acquiring pro-tumorigenic functions and endow them with anti-tumorigenic properties with the final objective to identify novel therapeutic approaches to enhance innate immunity against tumors. Inducible and cell-specific genetic mouse models mimicking human cancers will allow to molecularly dissect the immunmodulatory capacity of pDCs and tumor-associated myeloid cells (TAMs). State-of-the-art large scale single cell sequencing and computational analyses provide a platform to identify novel molecular pathways and open the possibility for testing new strategies in cancer immunotherapy. The clinical significance of our findings will be validated in human cancer samples and a close cooperation with clinicians ensures a fast predictive and therapeutic translation of our results. A deeper understanding of these mechanisms will be of fundamental importance to develop more effective and possibly curative therapies aimed at treating tumors and, most essentially, metastatic disease.
In TNT-TUMORS we had proposed to employ genetically engineered mouse models (GEMMs) and patient material from melanoma, hepatocellular carcinoma (HCC) and colorectal cancer (CRC) as model tumors to study two types of innate immune cells, namely pDCs and myeloid cells/macrophages and find ways how to modulate them to attack tumor cells and to enhance the effect of standard anti-cancer therapies. We had previously identified two independent mechanisms by which modulation of pDCs and EGFR-positive myeloid cells (EGFR+ TAM) inhibited the growth of solid tumors. We had shown that stimulation of pDCs with TLR agonists could transform them into cells capable of directly killing tumor cells without the need of the adaptive immune system. Second, we identified a tumor-promoting role of EGFR+ TAMs during colorectal cancer (CRC) and hepatocellular carcinoma (HCC) formation. This enabled us to look at the role of EGFR in tumorigenesis in a completely different way as most of the previous studies had associated the oncogenic function of the EGFR to its expression in tumor cells. Thus, the mechanism by which anti-EGFR drugs are effective in tumors needs to be re-evaluated.
We have characterized the AP1 transcription factors c-Jun and JunB as an important transcription factor controlling pDC and DC development, activation and recruitment during TLR-induced responses. Thus, therapies that broadly target AP-1 signalling could adversely affect the DC compartment (Novoszel et. al. Cell Death and Diff., 2021)
We identified c-Jun/AP-1 to be a critical downstream effector of TLR-7 signalling in DCs by transcriptionally controlling the production of important inflammatory cytokines involved in psoriasis development (Novoszel e. al. EMBO Mol. Med. 2021).
We developed a novel strategy of in-situ tumor vaccination using a combination of oral and topical TLR7/8 agonists in preclinical models of melanoma and breast cancer. This treatment approach enhanced tumor-specific CD8+ immune response that was further potentiated by anti-PD1 blockade. (Sanlorenzo, Novoszel et al. in prep).
We identified gene expression signatures and pathways modulating/conferring tumor killing capacities to activated pDCs in preclinical samples. These signatures were shown to be predictive for increased survival in melanoma and SCC patients. (Gastaldi et al. in prep).
We have characterized EGFR positive macrophages for their basic physiological functions.
We have performed RNAseq analysis of liver TAMs and identified that several immunotimulatory cytokines were upregulated in TAMs lacking the EGFR (Robl, Matrone et. al. in prep).
In collaboration with M. Karin’s laboratory, we could also demonstrate an interaction between CD44 and EGFR during HCC formation (Dhar...Glitzner et. al, Cancer Cell 2018)
We have performed single cell RNAseq on mouse CRC and found that EGFR deletion in myeloid cells leads to changes within the immune infiltrate that relieve the immunosuppressive environment leading to lower tumor burden (Fari, Neuhofer, in prep).
We showed that inducible EGFR deletion in tumor cells of CRC does not impinge on tumor growth (Srivatsa, Paul et al. Gastroenterology, 2017).
We developed an organoid-based metastatic CRC model in mice which is based on using GEMMs lacking the EGFR in different cellular compartments transplanted orthotopically with syngeneic mouse CRC organoids carrying different oncogenic mutations. This system allows to study how oncogenic mutations in tumor cells affect the tumor microenvironment and vice versa (Moreno-Viedma, Fari, Neuhofer, in prep).
We have established a novel mouse model of HCC that is based on the intrasplenic injection of luciferase-transduced Hep55.1c cells that lead to HCC in 4 weeks.
We characterized human CRC samples, detected EGFR+ myeloid cells in these tumors and correlated their presence to a worse overall survival of metastatic patients (Srivatsa, Paul et al. Gastroenterology, 2017).
We could also correlate the presence of EGFR positive myeloid cells and the response of CRC patients to anti-EGFR treatment (Moreno-Viedma, Taghizadeh, Göcen in prep).
We performed RNASeq analysis on dissected tumor and stroma of CRC patients and characterized how mutations in tumors affect stromal signatures and vice versa (Moreno-Viedma, Mohr, in prep).
We found the receptor Axl to be overexpressed in the stroma of advanced CRC patients where it correlates with a worse survival in patients (Cardone, Blauensteiner, Eur J Cancer, 2020).
We identified c-Jun/AP-1 to be a critical downstream effector of TLR-7 signalling in DCs by transcriptionally controlling the production of important inflammatory cytokines involved in psoriasis development (Novoszel e. al. EMBO Mol. Med. 2021).
We developed a novel strategy of in-situ tumor vaccination using a combination of oral and topical TLR7/8 agonists in preclinical models of melanoma and breast cancer. This treatment approach enhanced tumor-specific CD8+ immune response that was further potentiated by anti-PD1 blockade. (Sanlorenzo, Novoszel et al. in prep).
We identified gene expression signatures and pathways modulating/conferring tumor killing capacities to activated pDCs in preclinical samples. These signatures were shown to be predictive for increased survival in melanoma and SCC patients. (Gastaldi et al. in prep).
We have characterized EGFR positive macrophages for their basic physiological functions.
We have performed RNAseq analysis of liver TAMs and identified that several immunotimulatory cytokines were upregulated in TAMs lacking the EGFR (Robl, Matrone et. al. in prep).
In collaboration with M. Karin’s laboratory, we could also demonstrate an interaction between CD44 and EGFR during HCC formation (Dhar...Glitzner et. al, Cancer Cell 2018)
We have performed single cell RNAseq on mouse CRC and found that EGFR deletion in myeloid cells leads to changes within the immune infiltrate that relieve the immunosuppressive environment leading to lower tumor burden (Fari, Neuhofer, in prep).
We showed that inducible EGFR deletion in tumor cells of CRC does not impinge on tumor growth (Srivatsa, Paul et al. Gastroenterology, 2017).
We developed an organoid-based metastatic CRC model in mice which is based on using GEMMs lacking the EGFR in different cellular compartments transplanted orthotopically with syngeneic mouse CRC organoids carrying different oncogenic mutations. This system allows to study how oncogenic mutations in tumor cells affect the tumor microenvironment and vice versa (Moreno-Viedma, Fari, Neuhofer, in prep).
We have established a novel mouse model of HCC that is based on the intrasplenic injection of luciferase-transduced Hep55.1c cells that lead to HCC in 4 weeks.
We characterized human CRC samples, detected EGFR+ myeloid cells in these tumors and correlated their presence to a worse overall survival of metastatic patients (Srivatsa, Paul et al. Gastroenterology, 2017).
We could also correlate the presence of EGFR positive myeloid cells and the response of CRC patients to anti-EGFR treatment (Moreno-Viedma, Taghizadeh, Göcen in prep).
We performed RNASeq analysis on dissected tumor and stroma of CRC patients and characterized how mutations in tumors affect stromal signatures and vice versa (Moreno-Viedma, Mohr, in prep).
We found the receptor Axl to be overexpressed in the stroma of advanced CRC patients where it correlates with a worse survival in patients (Cardone, Blauensteiner, Eur J Cancer, 2020).
We expect to identify novel targets that can be modified for efficient transformation of pDCs into tumor killing cells. Moreover, we will identify the tumor-surveillance mechanisms mediated by EGFR+ myeloid cells. With these findings, we anticipate to improve immune-based anti-cancer treatment in future.