New chemical tools to diagnose and treat disease

Medical advances have played a fundamental role in dramatically increasing life expectancy in Canada and around the world. This has created challenges for the health-care system as a number of diseases exhibit increased incidence with age. Two examples include Alzheimer’s disease (AD) and cancer; cancer is now the leading cause of death in Canada. Continued research into the causes and progression of the disease is sure to provide advances in our ability to treat and eventually prevent the disease, with great benefit to our society and economy. The overall goal of Dr. Tim Storr’s biomedical research program is to develop new chemical tools to diagnose and treat the disease.

Storr’s team is focusing their research efforts in two areas: metal-overload diseases, and cancer. Many metal ions are essential to our existence, yet under certain conditions can become toxic. The team is currently studying the role of excess metal ions in the development of AD and Wilson’s disease (WD). The increased incidence of AD, and the lack of effective treatment strategies, underscores the pressing need for research into the causes, and the development of new therapeutic options. Storr’s team is investigating a new approach to AD treatment in which drug molecules are activated in the presence of excess metal ions, allowing for selective therapy. At the same time they are applying this treatment strategy to WD, a genetic metal overload disease in which excess metal ions accumulate in the liver. The overall goal is to bring forward new treatments for metal overload diseases that are generated at the site of need and only when excess metal ions are present.

Storr’s team is also applying chemical tools to cancer by developing imaging agents that allow for the early detection of the disease, and the ability to monitor treatment regimens. This information is key to a successful patient outcome, and the group is currently investigating differences in the energy needs of normal and cancerous tissue. Working at the interface of chemistry, biology, and medicine, this research promotes investigation across disciplines towards the design and testing of innovative disease treatments.

SHIP’s roles in intestinal immune homeostasis and inflammation

Dr. Laura Sly’s research program aims to improve our understanding of inflammatory bowel disease pathology and to identify and validate novel therapeutic approaches that will improve patient care. Her team has been investigating the role of SH2-containing Inositol Phosphatase (SHIP) in intestinal inflammation. SHIP is a protein that regulates enzymes involved in immune cell signaling. Sly’s research has shown that SHIP-deficient macrophages are hyper-responsive to IL-4, which drives them to an alternatively activated or M2 phenotype.

Using mice as a genetic model of M2 macrophages, Sly reported that M2 macrophages are protective against induced intestinal inflammation. Since then, her team has characterized a complimentary genetic model of M1-polarized macrophages and has identified key anti-inflammatory mediators that may be responsible for protection. Future investigations will focus on whether adoptive transfer of polarized macrophages or targeting macrophage polarization in situ can reduce intestinal inflammation in pre-clinical models of inflammatory bowel diseases.

Sly’s team has also developed a new mouse model of intestinal inflammation that shares key pathological features with Crohn’s disease. They have reported that SHIP-deficient mice develop spontaneous, discontinuous ileal inflammation accompanied by excessive collagen deposition and muscle thickening. Current research goals include targeting macrophage polarization or polarized macrophage products to reduce intestinal inflammation in pre-clinical models of inflammatory bowel disease, and identifying cell types and biochemical mechanisms that contribute to intestinal inflammation in SHIP-deficient mice. Together, these studies will identify cellular and biochemical targets and investigate new immunotherapeutic approaches that may useful in reducing intestinal inflammation in people with inflammatory bowel diseases.

HIV vaccine immunogen design to elicit broadly neutralizing antibodies

Existing viral vaccines provide immunity against a number of important infectious diseases. The technologies used to develop these vaccines generally work best against viruses that do not mutate very much in nature. However, conventional vaccine design approaches have proven inadequate for viruses such as HIV-1 that continuously evolve in order to evade our immune defenses. Thus, new vaccine design strategies are needed to tackle viruses like HIV.

Dr. Ralph Pantophlet’s research program is developing novel strategies for the design of vaccines that will induce broad immunity to HIV infection. Specifically, Pantophlet seeks to better understand molecular and immunological conditions that impact the elicitation of antibodies with the capacity to block the infectivity of a wide variety of HIV strains. This research focuses on these types of antibodies, dubbed “broadly neutralizing antibodies,” because of their demonstrable ability to block HIV infection in animal models. Another component of this program of research will be systematic studies to define neutralizing antibody target sites on HIV and investigate exposure of these sites at the molecular level. As part of the proposed research program, knowledge gained from the studies outlined above will be incorporated into the design of formulations to elicit target site-specific broadly neutralizing antibodies upon immunization. Thus, insight gained from this work is expected to advance HIV vaccine design efforts and be of significant interest to the field.

Although the focus will be on HIV, knowledge gained from this work may be applicable to other viruses for which conventional vaccine design approaches are also not optimal. Examples include hepatitis C virus, which like HIV is highly mutable and for which a vaccine has yet to be developed, and influenza, for which better vaccines are urgently being sought due to the constant threat of the emergence of a pandemic strain.

Keywords: HIV, vaccine, neutralizing antibody, immunogen design, vaccine immunology, B cell epitope, adjuvant, glycoprotein, T cell epitope, animal model

Uncovering novel regulators of beta cell genesis, growth and function

To date, the only successful approach for curing type 1 diabetes is to replace the insulin-producing beta cells that have been destroyed by the disease. Pancreas- and islet-cell transplantation are promising therapeutic strategies; however, scarcity of transplantable tissue has limited their widespread use. One way to produce enough beta cells to cure type 1 diabetes is to determine how the cells develop normally within the embryo and apply this knowledge to the regeneration of beta cells in the culture dish or directly in people with diabetes.

Using human and mouse model systems, Dr. Francis Lynn’s research aims to enhance our understanding of normal regulatory pathways that govern pancreas- and insulin-producing pancreatic beta cell genesis and function. The hope is that a greater understanding will enable cell-based approaches for treating and curing diabetes. Lynn’s long-term objective is to understand how regulatory DNA-binding proteins called transcription factors drive beta cell formation and function. This research specifically focuses on one member of the Sox gene family of transcription factors named Sox4. Preliminary data suggest that Sox4 is instrumental in governing both the birth of beta cells and their replication later in life. These observations place Sox4 as a novel and previously unappreciated key regulator of beta cell biology.

Lynn hopes that a thorough characterization of the pathways through which Sox4 regulates beta cell formation and function will inform novel approaches for generation of large numbers of functional beta cells from human embryonic stem cells or induced pluripotent stem cells.

A wearable assistive device for improving quality of life

Mobility of the upper extremities has a significant impact on independence and quality of life. For individuals with neuromuscular disorders due to aging, stroke, injury, or other diseases, the activities of daily living (such as eating and dressing) can be very challenging. However, biomedical robotic technologies offer a promising tool with which to improve the mobility of individuals with impaired upper extremities.

Collaborating with experts in the field of neuromuscular rehabilitation, Dr. Carlo Menon is leading the design and development of a smart assistive medical device that is portable and wearable. The objective is to develop a device that will assist with functional movements and strengthen muscular tone of the weakened or impaired extremities. The device will have potential use for both upper extremity assistance and rehabilitation.

This research will improve the quality of life for individuals with neuromuscular disorders by restoring mobility of the upper extremities. The proposed project will include the following phases: a) interaction with the neuromuscular collaborators to iteratively reformulate the design; b) the engineering design and development of the biomedical robotic device; c) the engineering testing of the device; d) a study of the interactions between the device and both healthy volunteers and individuals with neuromuscular disorders to verify that the device can assist functional movements; e) technology transfer to neuromuscular scientists and clinicians.

Characterization of the formation of protein aggregates induced by the inhibition of the ubiquitin proteasome system

Protein aggregation is a pathological feature of a large number of diseases with a strong preponderance in age-related neurodegenerative disorders like Parkinson’s disease. Failure to eliminate aberrant proteins in the cell plays a major role in these pathologies and is often linked to the impairment of the ubiquitin proteasome system, which degrades proteins labeled (or modified) with ubiquitin. The overall goal of Dr. Thibault Mayor’s research is to further define the involvement of the ubiquitin proteasome system in aggregation diseases using proteomic and cell biology approaches.

Mayor’s team has developed a new cellular assay to monitor the formation of aggregates induced by proteasome inhibition. They have identified by mass spectrometry more than 500 proteins that localize in these structures. Using a computational approach, Mayor will determine which features are shared among these proteins to give better insight into the mechanisms leading to aggregation. The UCHL1 enzyme may also be a major player in the aggregation process, and Mayor’s team will use the cell assay and mass spectrometry to further characterize UCHL1 and determine whether other enzymes related to the ubiquitin proteasome system may promote aggregation.

Current treatments for most aggregation diseases are primarily based on symptom management instead of directly treating the cause. Mayor’s work may potentially lead to a better understanding of the aggregation mechanism and identify novel targetable pathways to prevent formation or favor clearance of protein aggregates that could be used for new therapeutics.