- Determine the role of intrinsic immune checkpoint signalling in the progression of pre-malignant BO to OAC: expanding the target cohort for immune checkpoint inhibition.
Prof. Joanne Lysaght
AllCaN Oesophageal Principal Investigator
Dr Aideen Ryan
AllCaN Oesophageal Principal Investigator
Mr Sam Cahill
AllCaN Oesophageal Research MSc Candidate
- September 2024 (2 years)
Research question
Can we use innovative treatment strategies to alter inflammation and immune cell biology in the tissue microenvironment across the BO-OAC disease sequence?
Project Overview
In this project, we will determine if the dysregulation of immune checkpoint in BO can affect disease progression. The role of the evolving tissue microenvironment and supportive stromal cells in driving immune checkpoint dysfunction as the disease progresses will specifically be examined. This could lead to the identification of new immunotherapeutic targets in premalignancy, a largely untapped area for immunotherapeutic development. Cancer immunotherapy, in the form of immune checkpoint inhibition, has changed the face of cancer treatment, including GI cancers. While it uniquely offers the promise of a cure for a small cohort of patients, many patients only gain short-term or no benefit. Although immune checkpoint inhibition has largely focused on T cell dysfunction in cancer, Prof. Lysaght’s lab have detected expression of immune checkpoint receptors in pre-malignant epithelial cells, where their role is completely unknown. Moreover, Dr. Ryan has identified the expression of immune checkpoints by stromal cells in the tumour microenvironment, the role of which will be assessed in BO and OAC. We aim to fully elucidate these pathways to potentially identify mechanisms to slow or prevent disease progression.
Overview – Part 1 - Functional assess the role of immune checkpoint signalling in neoplastic epithelial cells
Epithelial cells representing the disease progression from normal, to metaplasia, to dysplasia and adenocarcinoma will be screened for immune checkpoint expression under basal growth conditions and physiological stress conditions found frequently in inflamed pre-malignant and malignant tissue, namely hypoxia, nutrient deprivation and acidosis. The functional consequences of relevant immune checkpoint pathways will be assessed using recombinant ligands or blocked using neutralising antibodies, and cellular functional readouts including immune checkpoint expression, viability, proliferation, metabolism and cytokine/growth factor production will be assessed. Flow cytometry, multiplex ELISA, CCK8 viability assays and real-time metabolic profiling using the Agilent Seahorse XF analyser will be used to functional assess changes in cellular function mediated by immune checkpoint signalling.
Overview – Part 2 - Assess the influence of stromal cells on immune checkpoint signalling and how this key compartment can drive tissue homeostasis or disease progression.
Mr. Cahill will be seconded to University of Galway to conduct this work. Human mesenchymal stromal cells derived from bone marrow, GI tract and tumour, will be generated in University of Galway and screened for immune checkpoint receptor and ligand expression by flow cytometry. Stromal cells will then be co-cultured with oesophageal epithelial cells (outlined in part 1) (contact dependent) or cultured in the presence of stromal cell supernatant (non-contact dependent), and changes in immune checkpoint receptor and ligand expression will be assessed under basal and stress growth conditions. Functional consequences of immune checkpoint signalling within the stromal cells will also be assessed using recombinant ligands or neutralising antibodies to assess changes in stromal cell viability, proliferation, cytokine, and growth factor release, assessed by CCK8 assay, flow cytometry and multiplex ELISA, respectively.
Anticipated impact of this AllCaN Oesophageal research project
This innovative translational work will ultimately lead to an important understanding of the role of immune checkpoints in BO-OAC cancer progression, which is currently unknown. It will also lead to the identification of new immunotherapeutic targets and more effective use of immunotherapy in both pre-malignant and malignant disease.