From Avian flu to Sepsis: latest CIHR funding round results for LMP

Janice Robertson, University Health Network (UHN)

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two closely related neurodegenerative diseases, both of which currently lack cures or effective treatments. These conditions involve progressive communication failure between neurons in the brain, a crucial function for maintaining brain health.

Understanding the reasons behind this breakdown in neuronal communication in ALS/FTD is vital for developing treatment strategies. The most common genetic cause of ALS/FTD is a mutation in a gene known as C9orf72. Our research has shown that this gene plays a key role in maintaining the brain's neuronal communication system.

Our project focuses on understanding how C9orf72 does this. By unravelling how C9orf72 helps maintain brain communication, we hope to pinpoint new treatment targets to pave the way for potential therapies for these devastating diseases.

Clinton Robbins, University Health Network (UHN)

The immune system balances defending against infections and preventing harmful inflammation. When this balance is disrupted, unchecked inflammation can cause tissue damage and disease. To restore equilibrium, the body relies on anti-inflammatory mechanisms, including regulatory plasmocytes (PCreg), which help suppress immune responses in autoimmunity, chronic infections, and cancer. However, identifying and using these cells for therapy has been challenging due to the lack of reliable markers.

Our research has identified Notch1 as a key marker of PCreg in both mice and humans. When expanded in the lab, PCreg up-regulate Notch1, highlighting its importance in their growth and function. Blocking Notch1 prevents PCreg expansion in mice and impairs their development in lab-grown human and mouse cells, suggesting it is essential for PCreg function and a potential therapeutic target.

Our project has three goals:

1. Defining the role of Notch1 in PCreg survival and function: We will determine whether Notch1 reliably marks PCreg, influences their survival and movement, and identify molecular pathways regulating human PCreg.
2. Investigating Notch1 in human PCreg generation: We will assess whether Notch1 is required for PCreg expansion, uncover how these cells suppress immune responses, and identify signals that promote their growth.
3. Testing PCreg therapy for graft-versus-host disease (GVHD): Using mouse and humanized models, we will evaluate whether Notch1+ PCreg can protect against GVHD, a life-threatening complication of bone marrow transplantation.

If successful, this research will pave the way for PCreg-based therapies in immune disorders.

Jeff Lee, University of Toronto with Co-Investigator, Jennia Michaeli, Sinai Health

Fertilization is a process where sperm and egg come together, but we still do not fully understand how it works on a molecular level, especially in humans. This lack of knowledge makes it harder to understand what causes infertility.

Our research has shown that two proteins, IZUMO1 on the sperm and JUNO on the egg, play a key role in sperm-egg attachment. These proteins, along with other recently discovered factors, likely are underlying causes of infertility. In this study, we plan to explore how sperm and egg fuse by looking at how certain molecules, like folate and zinc, might help control this process.

We will also examine clinical samples from patients who have struggled with infertility or unsuccessful in vitro fertilization to understand whether there is abnormal expression, localization and/or binding defects of IZUMO1 and other sperm fusion factors.

Finally, we aim to create new therapeutic strategies that can help improve the chances of sperm and egg successfully merging. By understanding these processes better, we hope to develop new tools to diagnose infertility and create personalized treatments, ultimately helping couples in Canada who want to have children.

Robert Kozak, Sunnybrook Health Sciences Centre, and Allison McGeer, Sinai Health

Respiratory viruses are a significant cause of morbidity and mortality and a burden to the healthcare system. The COVID-19 pandemic has demonstrated the potential of molecular testing and sequencing to advance our understanding of respiratory viruses. While considerable research has been done to date on influenza virus and respiratory syncytial virus, others such as parainfluenza, human metapneumovirus and the seasonal coronaviruses have not been as thoroughly characterized. This is despite the significant impact they have on the health of Canadians.

The objective of this proposal is to develop tools for identifying and characterizing non- influenza respiratory viruses in circulation in different patient groups. Additionally, we will collect real-world on transmission and infectivity in hospital settings.

Specific aims:

1. Characterize the genomic epidemiology of circulating respiratory viruses in Ontario.
2. Assess the association between viral variants and disease severity.
3. Understand transmission dynamics and infectivity in nosocomial outbreaks.

This proposal will address key questions on viral transmission and evolution as well as develop tools that can be immediately shared with the clinical community for ongoing surveillance. Additionally, it will provide valuable data that can improve hospital infection control practices and limit outbreaks.

Our group has an established record of translational research in respiratory viruses. Dr. Kozak is a clinical microbiologist and Clinician-Scientist. He has expertise in developing diagnostics assays. This proposal is being done in conjunction with TIBDN as well as collaborators at other microbiology laboratories to facilitate easy collection of patient samples. Collectively, the findings from this project have potential to better prepare Canada for future respiratory virus epidemics.

Rebecca Gladdy, Sinai Health (Department of Surgery) with Co-Investigator Adam Shlien, SickKids

Leiomyosarcoma (LMS) is a common type of adult sarcoma that arises from smooth muscle, which is only cured by surgery. Unfortunately, 50% of patients do not survive as they develop metastasis or spread of the cancer from the original site of LMS, as standard drug therapy is largely ineffective. Furthermore, we currently find it hard to define who has early LMS or not, especially in women with uterine smooth muscle tumors, which often results in under treatment.

In previous work from our LMS team, we found 3 subgroups of this cancer that have different outcomes. Also, we identified and are testing at least two new promising drug combinations based a genetic signature seen in the majority of patients. Finally, we have assembled a cohort of patients with benign or non-cancerous smooth muscle tumors that will be compared with LMS to define how to diagnose early LMS more effectively.

Thus, in this 5 year proposal we have 3 study goals:

1. To work on markers that can be used to separate the main groups of LMS that we have previously uncovered. This will include testing tumors from other sarcoma centers that have detailed patient outcomes. We will use standard laboratory and pathology techniques to separate these groupings, which then can be used to define good vs. worrisome patient groups for treatment.
2. We will work on the challenge of is a smooth muscle tumor cancer or not? To do this, we have a well archived collection of patient tissues and outcomes, from which we have begun to understand the early stages of this tumor. This will aid in deciding who needs aggressive treatment or not.
3. Our lab has generated at least two new drug combinations - standard chemotherapy plus a targeted agent for patients with LMS.

We will further work on markers to define why some patients/which subgroups respond to these combinations vs not, using our comprehensive LMS cell lines, mouse models and patient tissues. This information will aid in clinical trial development.

Mansoor Husain (Department of Medicine), University Health Network (UHN)

Heart failure (HF) is a leading cause of death and disability in people with high blood pressure, coronary artery disease, and diabetes. With aging populations, and global increases in obesity and diabetes, the incidence and health system burdens of HF are of pandemic proportions. As such, new ways of preventing and treating HF are needed.

Years of research have led to an emerging concept that HF is not just a problem of heart function, but of how the heart meets its energy needs. While healthy hearts use a variety of fuel sources, failing hearts cannot. Failing hearts have reduced capacity to generate energy, which may contribute to their inefficient pump function. This energy crisis may be due to changes in fuel supply or by a reduced ability to use certain fuels.

We have identified mitochondrial trifunctional protein [MTP], a key enzyme controlling fat breakdown, as a possible culprit in altering fuel sources available in HF. We will study the role of MTP in different types of mouse models of human HF, including HF after heart attack, after pressure overload, and HF caused by obesity and high blood pressure. We will also test if MTP can be targeted to prevent and treat different types and stages of HF.

First, we will cause HF in mice by blocking a coronary artery and causing heart attack, or blocking the aorta to increase pressure load on the heart, and by feeding mice a high fat diet and a drug that causes high blood pressure, to create the common obesity and high blood pressure-form of HF. We will then examine MTP expression- and enzyme activity in the hearts of these mice. Next, we will use genetically modified mice which allow for the deletion of MTP in heart muscle and blood vessel cells to see if this helps or harms HF. We will then examine function and metabolism of isolated hearts and heart tissues BEFORE and AFTER establishing HF. Finally, we will test if blocking MTP by GLP-1(28-36), a known inhibitor of MTP, can prevent or treat HF in our mice.

Jennie Johnstone (Department of Medicine), Sinai Health

BALANCE+: A Platform Trial for Gram Negative Bloodstream Infections with Principal investigators Nick Daneman, Robert Fowler, Todd Lee, Derek MacFadden, Emily McDonald, Sean Ong, Ruxandra Pinto, Benjamin Rogers

Bloodstream infections are a leading cause of death in Canada and worldwide, yet remain understudied, such that we do not know the best treatment strategies to be sure to cure the infection while minimizing harms of excess antibiotics causing antimicrobial resistance. Our Canadian Institutes of Health Research funded Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness (BALANCE) Randomized Controlled Trial was the largest ever trial among patients with bloodstream infection, enrolling over 3600 patients across 74 sites in 7 countries. BALANCE confirmed that 7 days of antibiotics was as effective as 14 days, and set the paradigm for treatment duration. However, many crucial questions remain. BALANCE+ provides a platform to efficiently answer multiple next questions that are important for patients with the most common kind of bloodstream infections. All hospitalized adult patients with the most common kind of bloodstream infections - caused by "Gram negative" bacteria - will be eligible to participate. At launch this trial is addressing whether to repeat a blood culture to document clearance of infection, whether or not to 'de-escalate' (going from a broad to more specific antibiotic), the best oral antibiotics to use when switching from intravenous treatment, whether to replace or retain intravenous catheters, and specific antibiotic selection for a difficult to treat group ('AmpC') of pathogens. As each question is answered, optimal therapies will be adopted into usual care, and new questions will be introduced into the platform of the trial. In this proposal we ask for continuation funding to complete ongoing questions, and to add a new antibiotic duration question informed by BALANCE. The evidence generated by BALANCE+ will improve cure for this vulnerable patient population while decreasing potential harms from using too many antibiotics for too long.

Randomised Arthroplasty infection worldwide Multidomain Adaptive Platform trial (ROADMAP) with Principal investigators Christopher Kandel, Nick Daneman, Joshua Davis, James Howard, Todd Lee, Derek MacFadden, Tom Snelling, Jesse Wolfstadt

Hip and knee joint replacements are the most common operations in Canada with over 120,000 performed annually. A dreaded complication is a deep infection of the joint that occurs in nearly 2%, a rate that has not changed over the past 15 years. As the Canadian population ages, joint replacements are occurring more frequently, resulting in a rise in the numbers of individuals suffering from a joint infection. Treating a prosthetic joint infection requires an operation together with extended courses of antibiotics and with treatment success varying between 40-90%, there is a need to improve. ROADMAP, an international randomized control trial, is seeking to determine the optimal surgical and antibiotic interventions for prosthetic hip or knee joint infections. ROADMAP is an adaptive platform trial, which is a study design that allows for multiple interventions to be evaluated at the same time and can continue indefinitely as additional comparisons can be added once the answer to an existing question is reached. The initial surgical arm of ROADMAP will compare joint removal versus joint retention for acute infection. The initial antibiotic duration arm will compare the duration of antibiotics when the infected joint is either removed and replaced in one operation or following the second operation when the infected joint is removed and replaced over two operations. The antibiotic choice arm will evaluate whether the combination of rifampin, an antibiotic, added to the antibiotic regimen is beneficial when the joint infection is caused by certain bacteria. The platform trial design of ROADMAP will allow for efficient generation of results, ensuring that individuals with a prosthetic joint infection receive the best care. ROADMAP will provide practice-changing evidence for prosthetic joint infections and improve the research infrastructure in Canada that will allow for continual evaluation of treatment strategies to constantly improve patient-oriented outcomes.

Stephen Juvet (Department of Medicine) University Health Network (UHN) with Principal Investigators Shaf Keshavjee and Bowen Li

Lung transplantation is the only treatment option for patients with end-stage lung disease. However, the transplanted donor lung is at a constant risk of inflammation, which can lead to organ rejection. Current post-transplant care involves lifelong treatment to suppress the recipient's immune system and prevent this outcome, but negative side effects require a new approach.

At University Health Network (UHN), we are leaders in bringing research breakthroughs to the patient bedside. Our team pioneered a breakthrough technology called the Toronto Ex Vivo Lung Perfusion (EVLP) System, where donor lungs are preserved at normal body temperature (37°C) and provided oxygen, nutrients and other critical needs before transplantation. This enables donor lungs to "breathe" outside of the body for up to 12 hours. With EVLP, transplant teams can make sure that the lung is acceptable for a life-saving transplant. During EVLP, the surgeon can also apply therapies to the donor lung to improve the immune response.

EVLP has resulted in up to a 100% increase in lung transplants performed and lives saved worldwide. Despite this success, recipients who receive a lung transplant still only live an average of 6.7 years, partly due to the risk of a damaging immune response that can lead to organ rejection. To address this issue, we will develop a way to safely deliver a powerful gene editor, called CRISPR-Cas9, to donor lungs and genetically improve the immune response in the organ.

With prior CIHR support, we were the first in the world to achieve genome editing human donor lungs on EVLP. Our goal for the next phase in lung transplantation will aim even higher-donor organs with a "built-in" ability to regulate the immune response. By creating longer-lasting organs, we will significantly extend recipient survival.

Our project strongly reflects CIHR's goal to translate research into new procedures that increase the quality of life of those in need across Canada and worldwide.