Rituximab is an anti-CD20 monoclonal antibody (mAb), approved for use in combination with standard chemotherapeutic agents for treatment of patients with CD20-positive B cell lymphomas. Although it provides significant benefits for lymphoma patients, it is not curative, and for several specific forms of lymphoma, rituximab offers little or no benefit. To date, the mechanism(s) underlying the anti-tumour activity of this mAb in vivo are not clear. However, one area of particular interest is in activities that involve clustering of the CD20 molecule on the cell surface. Clustering of CD20 has been shown to elicit changes in cell signalling pathways that promote cell death, while enhancing sensitivity of lymphoma cell lines to cytotoxic agents. By better understanding this mechanism of antibody-induced tumour death it will be possible to determine the clinical basis for insensitivity to rituximab. Jesse Popov’s research is exploring this mechanism of activity by comparing a novel, highly active multivalent form of rituximab that he has developed, to the activity of rituximab. The results of his research will provide for improvements on the novel mAb he has developed and may also provide a possible therapeutic alternative to rituximab. Importantly, this novel agent can be made with any therapeutic antibody, not just rituximab, which means that it has the potential to be used for treating virtually any type of cancer. Such improvements over current therapies translate directly into a higher quality of life for cancer patients.
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The Relationship Between the Immune System and the Normal Gut Microflora in Salmonella Typhimurium Infection: A Two Sided Tale
Understanding the role of the microbiota in the development and progression of diseases has received a great deal of attention in recent years. The microbiota is defined as the group of microorganisms, such as bacteria, which normally inhabit the human body. These microorganisms, also known as microflora, are composed of a variety of species of bacteria, each having a different function, and there are some bacteria whose functions remain unknown. Several studies have shown that patients with inflammatory bowel diseases, such as Crohn’s Disease, have a microbiota composition that is different from healthy individuals, suggesting that certain species of bacteria might be important in causing some common gut inflammatory disorders. Dr. Navkiran Gill is investigating how the human immune system regulates the microbiota and how our microbiota may direct our immune responses to various pathogens. Specifically, she is doing a series of experiments involving antibiotic use in specially bred mice infected with Salmonella. The results will provide important information regarding the effect of antibiotics on the microflora, and allow her to correlate changes in our microflora to changes in our ability to mount an immune response against a pathogen such as Salmonella. The results of Dr. Gill’s research will provide information that may be used to design new therapeutics that take into consideration the important role of our microflora.
Knowledge representation in Health Research: the Canadian Influenza Research Network model
The Public Health Agency of Canada estimates that influenza infection currently results in an average of 20,000 hospitalizations and 4,000 deaths each year. Therefore, an influenza pandemic would have severe health, economic and social consequences. The Public Health Agency of Canada/Canadian Institutes of Health Research Influenza Research Network (PCIRN) was developed to identify research gaps in the country's pandemic influenza preparedness initiative. To facilitate the initiative, research will be done at various sites across the country, supported by a common information technology (IT) group. An essential mission of the IT support group is to develop standards ensuring proper communication and knowledge transmission amongst the different members of the network. Currently, differences in interpretation of the 'meaning' of data or semantic heterogeneity pose a significant challenge to combine information from multiple heterogeneous sources. In order to efficiently integrate information generated by the various centres constituting the network, a consistent representation of data must be adopted.
Mélanie Courtot's research centres on the development of a model to unambiguously interpret influenza data. Working in collaboration with Dr. Scheuermann, leader of the BioHealthBase project, the equivalent of the PCIRN network in the United States, Ms. Courtot will develop a guideline outlining the minimum information required, and derive a data model that captures the necessary elements and the semantic relationships between them, which will allow for the integration of Canadian and American data, thereby assisting in the development of a North American influenza data network. Establishment of standards for unambiguous data representation and investigation modeling will improve the integration and re-use of information produced, and ultimately increase the quality and re-usability of that information and decrease the cost of health care.
Place and experiences of risk among young drug users in downtown Vancouver
Illicit drug use is associated with severe harms and immense social suffering among youth. Previous ethnographic work has shown how social-structural and cultural processes present within specific urban locales intersect to push young people who engage in drug use towards ‘risk’, until it becomes difficult or impossible for them to avoid transitioning into increasingly ‘risky’ behaviours. However, there have been relatively few in-depth investigations of drug-using contexts or ‘scenes’ that focus exclusively on the meanings, understandings and everyday lived experiences of young drug users themselves. Danya Fast’s research explores young people’s understandings of the social-structural and physical landscapes of the downtown Vancouver drug scene, and how various locales (e.g. neighbourhoods, alleyways, service locations, residences), shape experiences of ‘safety’ and ‘risk’ among drug-using youth. Her approach emphasizes the influence of place on health, where place is understood to encompass both physical and social spaces. An important goal of this research will be the identification of elements in the physical and social environment that shape risk and structural interventions that alter context and, by consequence, facilitate safer spaces for work, rest and recreation for youth. Ms. Fast’s project will result in a more comprehensive and culturally sensitive account of young drug users’ everyday experiences in the context of the downtown Vancouver drug scene, and will also be used to inform ongoing epidemiological research with drug-using youth. Moreover, Ms. Fast’s project will contribute to the development of an ongoing ethno-epidemiological research program that has been identified as an important emergent area within Human Immunodeficiency Virus research, due to its unique ability to inform the development of interventions designed to reduce drug-related harms.
The role of Raf-1 in pancreatic beta cell survival and insulin signaling
While we know that Type 1 diabetes is caused by the destruction of insulin-secreting beta-cells in the pancreatic islets, the processes that regulate beta-cell death remain unclear. This has hindered the development of strategies to halt or prevent the development of diabetes. One possible new treatment, islet transplantation, was initially heralded as a promising therapy for Type 1 diabetes because it removed the need of daily insulin injections. However, the transplanted beta-cells were found to gradually die, which resulted in transplant recipients having to resume the use of insulin injections. In order for islet transplantation to be effective, new approaches to promote islet survival are required. In earlier work, Dr. Gareth Lim’s colleagues identified insulin as a critical pro-survival factor for beta-cells. Their findings suggest that secreted insulin from beta-cells may promote self-survival. However, the mechanisms that lead to the beneficial effects of insulin need to be clarified. Consequently, Gareth Lim is currently investigating the mechanisms by which insulin acts on the beta- cell. Specifically, he is doing a series of experiments to show that the protein Raf-1 kinase, which is activated by insulin and has been shown to have an important role in regulating cell death, is essential for beta-cell survival. The results of his studies will improve our understanding of the mechanisms of beta-cell death. They may also lead to novel therapeutic strategies for preventing beta-cell destruction in Type 1 diabetics and their at-risk relatives. Furthermore, an understanding of the pathways involved in beta-cell survival may also lead to new methods to increase the survival of beta-cells after islet transplantation, thereby increasing the effectiveness of this treatment.
Defining the Transcription Factors Capable of Forming Pancreatic Beta-Cells from Human Embryonic Stem Cells
In Type 1 diabetes the body’s immune system attacks key cells of the pancreas known as beta-cells. The loss of these cells results in a loss of the protein hormone insulin which is secreted by the beta-cells in response to high blood sugar levels. Recently, advances in the field of pancreatic islet cell transplantation have shown that the replacement of beta-cells represents a possible cure for diabetes. Unfortunately, the poor availability of donor organs to provide the transplantation cell source greatly limits the use of this treatment. One promising possible source of new beta-cells for transplantation is human embryonic stem cells (hESCs,) and a number of researchers have shown that these cells can form pancreatic tissue including beta-cells. Blair Gage is currently exploring how proteins known as transcription factors (TFs), control the formation of beta-cells from hESCs. Specifically, he is investigating whether adding TFs, which help in the formation of beta-cells, and removing the TFs, which block the formation of beta-cells, will help in understanding how to control hESC growth and development. The results of Mr. Gage’s research will enhance ongoing work with industry and the Canadian Stem Cell Network that is focused on stimulating hESCs to form beta-cells for transplantation. The ultimate goals is to apply this technology to the treatment of patients with diabetes in a similar way to that of islet tissue transplantation, using a theoretically limitless supply of beta-cells.
Social Attention and Visual Exploration in Children with Autism Spectrum Disorders
Autism is a severe neurological developmental disorder characterized, in part, by social impairment. A key social impairment present early in the development of children with autism is abnormal gaze following. Children with autism often do not follow the eye-gaze of others towards objects or events in the environment, which hampers their development of language and social skills. It may be that the seemingly abnormal gaze following evident in children with autism results from abnormal basic attentional responses to gaze cues. Clinical reports suggest that when in object-rich environments, these children demonstrate a diminished ability to focus on socially meaningful stimuli. Therefore, further research focusing on the ability to orient to gaze cues within complex visual environments such as classrooms, is critical. Adrienne Rombough has developed a computer task that examines orienting responses to gaze cues within complex visual scenes. In her current research she is using this program to examine the ability of children with autism to detect changes in complex visual scenes with or without the presence of gaze cues. Her study is designed to compare the performance of school-aged children with autism to that of mental age-matched, typically developing children. Her short term objective is to address the question of whether (and to what extent), the attention orienting response to gaze cues is abnormal in autism. This is the first known study to use an alternative, indirect measure of attention (i.e. change detection), to investigate gaze cueing within complex visual scenes. Over the longer term, Ms. Rombough’s findings could potentially improve the present understanding of how children with autism use social cues to explore their visual environments and how this skill set is potentially related to social impairment. The project is part of a larger research program designed to characterize the cognitive underpinnings of social impairments in autism.
Real-time fMRI training of functional connectivity and adaptive self-awareness
Awareness of one’s thoughts and feelings represents one of the highest mental processes in humans. Its dysregulation leads to rumination, which involves repetitively focusing on negative experiences and mental events. Rumination is consistently and strongly related to depression as both a precursor and a symptom, and therefore has important treatment implications. Given the high rates of relapse and treatment dropout in depressed individuals, a need exists for ongoing and immediate feedback in cognitive therapies that could facilitate learning and treatment compliance, and thereby improve clinical outcomes in people with depression. Real-time functional magnetic resonance imaging (fMRI), can add ongoing and immediate feedback to mindfulness-based cognitive therapy to increase its effectiveness. Mindfulness, a relatively successful treatment for depression, is an adaptive moment-to-moment awareness of mental events without controlling or elaborating (i.e. ruminating), and recruits both the anterior prefrontal cortex (PFC), (associated with cognitive and emotional self-awareness and self-regulation), and the anterior insula (associated with awareness of the self in the present moment). Previous studies show that people can successfully use real-time fMRI feedback along with awareness of their thoughts and emotions to modulate activation in the anterior PFC and the anterior insula separately. Melissa Ellamil is using real-time fMRI to examine whether it can help increase a person’s modulation ability over the functional connectivity between their anterior PFC and insular cortex and thereby improve the outcome of the strategies taught in mindfulness-based cognitive therapy. Ms. Ellamil’s research complements ongoing investigations using real-time fMRI to define functions and interactions of various regions of the brain. Her results could fine-tune the real-time fMRI feedback and self-awareness strategies and thereby enhance and prolong the results of cognitive treatments for depression.
The role of Apical Junction Complex in airway epithelial repair and differentiation in asthma
Asthma is a serious global health problem, affecting over 300 million people worldwide. The disease is predominantly an inflammatory disorder of the conducting airways, and can be treated or controlled using current therapies. However, un-controlled asthma leads to continual inflammation and damage, resulting in permanent scaring which is termed airway remodeling. Airway remodeling can be defined as changes in the composition, content and organization of cellular and molecular constituents of the conducting airways. One of the structural changes that occurs as a result of airway remodeling is detachment of the cells that line the surface of the airways, called the epithelium. In normal airways, the epithelium forms a barrier against the inhaled external environment which includes aero allergens, viruses and particulate matter, through the formation of apical junction complexes (AJCs). In asthma, part of the abnormal response to inhaled allergens is thought to be due to impaired barrier function caused by damage to the airway epithelium and loss of AJCs. Emerging evidence suggests that AJCs are able to influence other aspects of epithelial function such as release of inflammatory mediators and mechanisms of epithelial repair. Building on earlier work in this area, Dr. Tillie-Louise Hackett’s current research is designed to determine whether AJCs play an important role in normal airway epithelial repair and if the mechanisms involved are altered in asthmatic patients. The results of her research will provide scientists and clinicians with a better understanding of the pathological mechanisms that contribute to multiple respiratory diseases. In addition, Dr. Hackett’s findings will open avenues for the development of new therapeutics to improve the lung health of Canadians living with obstructive lung diseases, such as asthma and Chronic Obstructive Pulmonary Disorder.
Defining Immune Abnormalities And Their Consequences In The HIV Exposed But Uninfected Child
The primary route of infection for human immunodeficiency virus (HIV), in infants is from mother to child. Following the introduction of ‘Prevention of Mother To Child Transmission’ (PMTCT), programs, HIV infection rates in newborns from mother to child (vertical transmission), have been reduced from 30 percent to less than five percent. As a result, the number of ‘HIV Exposed but Uninfected’ infants (HEU) has steadily risen. In South Africa, where 30 percent of all women of childbearing age are HIV infected, 300,000 HEU births occur per year. Recently, infection and death rates among HEU infants have been determined to be much higher than those in HIV unexposed (UE) infants. Consequently, there is an urgent need to understand why HEU infants are so vulnerable to infections. Briefly, when a person is exposed to an infecting microbe, two major arms of the immune system respond: innate immunity, which keeps the microbe at bay, and adaptive immunity, which eventually clears the infection. While it is now known that alterations in the adaptive immune system of HEU infants do take place, there is little known about how the innate immune system of HEU compared to that of the UE infant. Mr. Brian Reikie, working in collaboration with Stellenbosch University, South Africa, is conducting a pilot study to determine whether exposure to HIV, in the womb or around birth, activates the innate immune system, which then causes damage to the adaptive immune system. As well, he will explore the HIV-innate-adaptive interaction to help explain why HEU infants are so susceptible to infections. Beyond the study of HEU, this will be the first demonstration of how innate immune responsiveness correlates with development of either normal or altered adaptive vaccine immune responses over time. The findings from this project will provide the essential groundwork for urgently needed guidelines for appropriate treatment and clinical follow-up of this vulnerable population.