Year: 2008

Myocarditis is a disease that results in inflammation of heart muscle. Myocarditis and dilated cardiomyopathy (DCM), a condition in which the heart becomes weakened and enlarged, are believed to be continuing stages of an autoimmune disease of the heart. This condition can progress to a stage that requires heart transplantation. Myocarditis is often brought on by a viral infection. In humans, coxsackie B viruses (CBV) are the most frequent cause of viral-induced myocarditis. It is estimated that 30 per cent of new DCM cases in North America are the result of CBV infection. Maya Poffenberger’s research aims to determine the specific immune components that control myocarditis disease severity following viral infection. She is studying cells and molecules that control immune cells. Using mouse models that lack certain immune genes, Poffenberger will be able to identify the genes that influence the induction and severity of myocarditis from CBV infection. With knowledge of how myocarditis is induced and controlled, researchers will be able to develop better disease specific therapies that target immune genes important to disease induction and severity.

The ABO blood groups – comprising the A, B, AB and O blood types – are vitally important in blood transfusion and organ transplantation. The four types are differentiated by the presence or absence of two sugar antigens on the surface of red blood cells: a terminal alpha-1,3-linked N-acetylgalactosamine (A-antigen) or an alpha-1,3-linked galactose (B-antigen), both of which are absent in the O-blood type. As all individuals have antibodies to the antigen(s) they lack, transfusion with an incorrect blood type results in destruction of the incompatible blood cells, which can result in death. The enzyme EABase is capable of releasing both the A and B trisaccharides from the surface of red blood cells, giving it the potential to be used to convert blood cell types by the addition or removal of their antigens. Fathima Shaikh’s studies seek to determine the mechanisms underlying EABase activity, and identify the residues that are created as a result. Knowledge of these enzyme properties is crucial for the next stage of the project: engineering EABase into a glycosynthase, which is a mutant form of the enzyme that can synthesize (form) antigens, rather than removing them. She will conduct further work to optimize the efficiency of this glycosynthase, as well as increasing its synthetic utility by broadening its ability to transfer different sugars. If Shaikh’s experiments are successful, this process would allow for the conversion between blood groups. These enzymes could be of great benefit to human health, helping to overcome shortages in donated blood, and helping in the modification of related antigens on other cell types.

Antibodies are proteins produced by the immune system. They work by selectively and tightly attaching themselves to infectious bacteria, viruses, and other pathogens, neutralizing their disease-causing abilities. The natural role of antibodies in clearing infections has prompted the pharmaceutical industry to invest billions of dollars in attempts to produce new antibody therapies to treat rheumatoid arthritis, cancer, cardiovascular disease, HIV/AIDS, and other diseases. As a result, antibodies have become the most rapidly growing class of therapeutic drugs over the last decade. One successful example of an antibody-based therapy is the drug Herceptin, which treats a highly-aggressive form of breast cancer. In order to produce vast quantities of antibodies required for research and therapeutic use, antibody-producing cells are currently fused to immortal cancer cells to allow them to be grown in laboratory culture. Successfully creating antibody-producing fused cells can involve hundreds to thousands of attempts, requiring many years and millions of dollars in research money. MSFHR previously funded Anupam Singhal as he used micron-sized fluid-handling devices and nanotechnology to allow the study of stem cells at the single cell level. He is now using these approaches to rapidly and inexpensively produce antibodies. He is working on a novel technology that is sensitive enough to detect antibodies produced by single cells, and determine which ones are producing the optimal antibody. Then, the genes responsible for antibody production in these cells can be isolated, cloned and inserted into cell lines for production. As a demonstration of this technology, human antibodies against the influenza virus will be developed. This technology could have far-reaching impacts on the rapid and inexpensive development of breakthrough therapeutic drugs and diagnostic agents.

Inflammation is the response of the body to infection or injury, triggered by the release of proteins that initiate inflammation. Amongst these proteins are members of the chemokine family. Chemokines act as biological beacons, guiding the migration of white blood cells (WBC) from blood vessels to the affected tissue. The structure of chemokines is important to their function. One end of the chemokine binds to tissue and vessels to create a path for white blood cells to follow; the other end interacts with a receptor on the surface of the WBC, prompting the release of further inflammatory mediators that spread the inflammatory response. Recruited and activated WBC attempt to isolate and destroy infectious agents and to prevent further damage. WBC – and in particular cells called macrophages – then help resolve the inflammatory response. In chronic inflammation, continual recruitment and activation of macrophages results in excessive production of reactive molecules that cause host tissue damage, as observed in diseases such as rheumatoid arthritis, multiple sclerosis and chronic obstructive pulmonary disease. The apparent deregulation of macrophage movement may be a result of a change in the structure and function of chemokines. Matrix metalloproteinases (MMPs) are a family of enzymes that modulate chemokine activity by cutting off a portion of either end of the chemokine, which keeps it from functioning properly. Amanda Starr is looking at the functional effects of MMP cleavage on chemokines that recruit and activate macrophages, determining whether cut chemokines are more able to attract and activate macrophage-like cells. She is also developing a technique for detection and quantification of both full-length and cut forms of chemokines from tissue samples. Ultimately, this knowledge could lead to more appropriate and directed therapeutics for the treatment of chronic inflammatory diseases.

In the development of a vaccine against four strains of the human papilloma virus (HPV), of particular note were studies involving innate immune response when genes of the virus were introduced into host cells. It was observed that increased levels of antibodies were produced by inoculation that used synthetic versions of two HPV genes. The application of gene vaccines, not only for cancer immunization, but also to aid the treatment of infectious diseases, is an ongoing and very active area of study. Developing an efficient and reliable method to produce synthetic DNA is a necessary tool for these studies to succeed. Due to the inherent difficulty of creating long strands of DNA, current technologies for gene synthesis use computational methods for design of shorter DNA fragments called oligos (oligonucleotides), which can be reliably synthesized and assembled. However, ensuring a set of oligos will self-assemble correctly into a longer DNA strand is difficult and complex, and previous software programs have failed to solve this issue. Chris Thachuk is a computer scientist who develops synthetic gene design algorithms. He and his colleagues are developing algorithms to successfully assemble long strands of DNA from oligos. These new algorithms outperform the current state-of-the-art and their effectiveness has been demonstrated through computational experiments on a large set of genes. Three average size genes have been produced with the aid of these algorithms. He now intends to build upon this success by extending the algorithms to produce reliable designs for synthesizing long genes and for synthesizing multiple genes in one step. By providing researchers with more advanced algorithms and accurate modeling software for gene synthesis, Thachuk hopes to contribute to new insights for treatment, detection and/or prevention of diseases.

During embryonic development, precursor muscle cells (myoblasts) are generated in one region of the embryo and then dispersed throughout the body. These migrations are controlled by external signals that guide the migrating cells. Previous muscle research has identified genes for muscle differentiation and development, but the important genes regulating muscle cell migrations have are unknown. Muscle cell migration is of particular importance for a new treatment called myoblast transfer therapy, which is being developed to treat muscular dystrophy and hearts damaged by cardiac arrest. The treatment injects healthy myoblasts into the damaged area in order to repair the affected tissue. A key problem in this treatment is that, for both cardiac and muscle tissue, the myoblasts fail to migrate properly and effectively colonize the damaged area. Ryan Viveiros is studying the embryonic development of a small nematode worm called Caenorhabditis elegans. While substantially simpler than humans, these worms also have muscle and share a number of the same genes required for muscle development as mammals. Because the worm embryos develop inside clear eggs, Viveiros can record the developing embryo and watch the cell migrations in real time. Computer software then allows him to follow the cell migrations and determine which cell types are defective. Viveiros will search for the genes that cause improper muscle migration and determine where these genes are turned on in the embryo. In addition to determining the basics of how muscle migration occurs, Viveiros hopes his findings could lead to new insights for improving myoblast transfer therapy. In addition, because this research is also relevant to cell migration in general, his findings may also inform our understanding of how cancer cells migrate (metastasize).