Our immune system protects of our body by detecting and destroying cells that are potentially cancerous. Sometimes, our immune system fails to detect a problem, leading to cancer. In pediatric cancer, CD8 T cells fail to destroy cancer cells. CD8 T cells are white blood cells specialized in the detection and attack of cancer cells. Like us, CD8 T cells need to “eat” to stay alive, to move, and to function. Without nutrients, they can’t fight off cancerous cells. In cancer, there is a fight for nutrients between CD8 T cells and cancer cells. CD8 T cells have to quickly adapt to make sure they can maintain their protective functions. We know that CD8 T cells can rapidly switch from using nutrients to grow, to burning them to make energy, but we do not know how it is regulated. The aim of my project is to study how CD8 T cells know which nutrients are around them, and how they “choose” to switch between growing and burning. Why is it important? If we grow CD8 T cells in a laboratory setting, restrict their food, and re-feed them, they provide better protection against cancer. Understanding how CD8 T cells “eat” and use nutrients to grow or burn energy to kill cancer cells will help develop better therapies to treat pediatric cancer.
Year: 2022
Outcomes of a ketogenic dietary intervention on the gut microbiome-microglial brain axis and schizophrenia-like behaviour in mice exposed to a double-hit immune challenge
Alterations in microorganisms present in the gut are associated with various mental health disorders. It is possible that this is due to changes in microglia, the immune cells that fight infections in the brain. Microglia can consume neurons, which are the cells that talk to one another in the brain. It is possible that changes in gut microorganisms make these immune cells to eat up brain cells excessively and uncontrollably, which causes mental illness. To understand this, we will infect laboratory mice with infectious agents during pregnancy and expose them to stress during adolescence. After testing the mice for behavioral alterations, we will use imaging techniques to assess how gut microorganisms can influence microglia. We will then determine if ketogenic treatments with a clinically approved high fat and low carbohydrate diet, showing benefits on the gut and brain, can reverse harmful effects on these immune cells in the brain. Together these investigations will provide novel insights into how the gut microorganisms can affect the brain immune cells and alter behavior, resulting in mental illnesses. This research may provide new targets for the therapeutic management of mental health conditions that include schizophrenia.
The impact of the COVID-19 pandemic on access to adequate care for serious mental disorders in British Columbia
The Covid-19 pandemic has created new challenges for the treatment of serious mental disorders such as schizophrenia and bipolar disorder. Patient avoidance of health services and the rapid switch from in-person to virtual delivery of services may have created barriers to accessing specialist services. The aim of the current study is to evaluate whether access to adequate psychiatric care for serious mental disorders changed between 2015 and 2022, and particularly after the onset of the pandemic. In addition, we will examine whether any disparities in access by demographic (age, sex, neighbourhood income quintile, geographic location) clinical (diagnosis and presence of substance use disorder) and health system factors have increased or decreased over this time period. Findings from this study will have important implications for the provision of mental health services for serious mental disorders in British Columbia.
Cost-efficient approach for phenotyping cells in large cohorts and relating them with COPD clinical outcomes
In Canada, over 2 million people suffer from COPD, costing over $1.5 billion per year in direct expenditures. However, no existing therapy can reverse COPD’s disease progress. Alveolar macrophages (AMs) are the lungs’ dominant immune cells and perform critical functions, including fighting infection and tissue repair. Single-cell genomics technology can characterize AM phenotypes and reveal their roles in COPD. However, validating the relation between AM phenotypes and COPD clinical outcomes requires many patients, making the unscalable single-cell technology impractical to study such large cohorts. This issue motivated me to develop a cost-efficient approach to discover cell-phenotype biomarkers, using both high-resolution single-cell and low-cost bulk genomic technologies. I will develop novel statistical methods and software tools for this novel approach. The key deliverables are: 1) an experiment protocol, novel statistical methods, and the first software pipeline for cost-efficient deep-phenotyping of large clinical cohorts, to discover biomarkers for ANY diseases; 2) novel AM phenotype biomarkers as drug targets of immunotherapy for COPD or a genomics diagnostic test (medical device) to guide personalized COPD treatment.
Targeting efferocytosis to reduce risk of cardiovascular events
Heart attack and stroke are the leading causes of death in Canada. These lethal events are caused by diseased cells accumulated on the wall of the blood vessels, leading to narrowing of the arteries. Although diseased cells can be removed naturally, this process is inhibited by inflammation. Recently, anti-inflammatory drugs are being actively developed to reduce heart attacks, but we lack methods to assess their effectiveness before testing in patients. This problem led to the failure of several clinical trials and serious side effects due to non-specific inhibition of the immune system. We will use models that closely mimic the conditions of patients and apply a thorough “onsite inventory” of diseased arteries to: 1) understand how inflammation inhibits the removal of diseased cells; 2) see if current drug candidates can neutralize these adverse effects in diseased arteries; and 3) explore and develop markers that can find patients who will benefit from the drug candidates. This study will provide evidence to guide the design of more specific anti-inflammatory drugs and their application to the right patients. It will minimize side effects and allow more patients to be properly treated to prevent heart attacks and strokes.
Developing sensors for rapid detection of biomarker proteins for Alzheimer’s disease
Dementia is a growing health challenge that affects over 500,000 Canadians today, which is estimated to grow to 900,000 by 2030. Alzheimer’s disease, the most common form of dementia, is characterized by protein misfolding in the brain. This process can start over a decade before the occurrence of significant cognitive decline making it possible to diagnose at an early stage when treatment strategies are most effective. Biomarkers are measurable indicators that help determine if a person may have or be at risk of developing a disease. Researchers have identified phosphorylated tau (p-tau) proteins and small proteins called cytokines to be promising biomarkers for Alzheimer’s disease. To detect these biomarkers in blood samples, very sensitive detection methods are needed but existing methods have drawbacks such as being expensive and time consuming, and need to be performed in a laboratory, limiting their availability to Canadians. We have developed a new sensor that can detect proteins at ultra-low concentrations using a simple and rapid test. Our goal is to make a rapid and easy-to-use tool that can be used by clinicians to help diagnose Alzheimer’s disease and patients for personalized health monitoring.
The links between nutrient sensing, cell intrinsic metabolism and T cell function in immune-related diseases
Our focus is on the cellular fuels and building blocks that change immune cell functions. Our immune system normally defends us against infections. In a healthy person, T cells (a type of immune cell) recognize infected or cancerous cells and remove them from the body. Normally, immune cells know the difference between healthy and infected or cancerous tissues. When this recognition is lost, it can lead to the development of attack of healthy tissues by immune cells (autoimmunity), the growth of cancer, or to persistent infections. This dysfunction of the immune system can lead to devastating diseases in children. My research aims to better understand how this happens. By comparing the way that biological fuels (sugars, fats and other building blocks) are used by immune cells from healthy people and patients with immune system associated diseases, we will define the cellular the pathways that maintain health or cause disease. This will allow us to target and “dial down” pathways that are driving cells to attack our tissues, or turn these pathways on to help immune cells fight persistent infections and cancerous cells. Ultimately, we hope to help develop new treatments.
Improving access to culturally safe, gender affirming, and trauma-informed abortion services and support for Indigenous women, Two-Spirit and LGBTQIA+ people in Canada
While Canada is currently one out of four countries globally to have no national restriction in law, the 2016 UN Human Rights Commissioner’s report indicated a lack of access to abortion due to cost, knowledge, and geography. For Indigenous Women, Two-Spirit, and LGBTQIA+ people in Canada, additional barriers exist including colonialism and racism. Yet there is an alarming gap in the literature surrounding Indigenous peoples and abortion services — despite knowing that one in three people in Canada will experience an abortion in their reproductive lifetime. The goal of this program of research is to build on existing community knowledge and strengths, advance knowledge around, and remove barriers to abortion services for Indigenous Women, Two-Spirit, and LGBTQIA+ people in Canada. Guided by an Indigenous feminist framework that acknowledges the intersectional experiences of Indigenous women, Two-Sprit, and LGBTQIA+ peoples and abortion access, this program of research will apply an Indigenous methodology to investigate experiences, gather knowledge, and co-develop resources to improve the abortion access gap among Indigenous peoples.
Examining motor imagery-related brain function in health and after stroke to leverage its prescription
Many stroke survivors (~85 percent) in Canada experience long-term impairments in arm and hand function. To aid recovery, motor imagery (the mental rehearsal of movement) shows promise as an adjunct therapy. Yet, its effectiveness is varied. We think this is due to a lack of basic knowledge about how motor imagery works. Motor imagery is thought to work similarly to physical therapy, whereby repetitive physical practice drives changes in brain function necessary for learning and recovery. However, we do not know a lot about how motor imagery drives changes in brain function. Using a blended approach not yet taken, we will examine changes in both brain function and behaviour driven by motor imagery. Importantly, we will examine how changes in brain function are altered and can be optimized after stroke, to improve its effectiveness. Findings will provide new information about how motor imagery should be applied to maximize learning and recovery, directly informing its use and prescription in stroke rehabilitation. Overall, this research represents a critical step in improving interventions for stroke recovery, leading to improved daily function and better quality of life for Canadians living with stroke.
Valvular heart disease and bioprosthetic heart valves: Defining mechanisms of degeneration and therapeutic discovery from bedside to bench
Aortic stenosis (AS) is a narrowing of the valve that controls blood flow from the heart to the body. AS results in significant decline in quality of life and can be fatal if untreated. Unlike most types of heart disease, there is no medication to treat AS and the primary therapy option is replacing the diseased valve with an artificial one by open-heart surgery or transcatheter implantation (insertion of an artificial valve through the blood vessels leading to the heart). Unfortunately, artificial valves can be dysfunctional and have limited durability, which can lead to heart failure, the need for repeat valve replacement, or death. With a focus on clot that can form on artificial valves, this research aims to determine the causes of valve dysfunction and degeneration, define methods to detect and predict which patients will experience valve dysfunction, and identify methods to increase valve durability. Overall, this work will provide critical new information to guide clinical care and the future evolution of artificial heart valve use that will improve the outcomes and quality of life of patients with AS.