neoformansis a polysaccharide (PS) capsule. Although O-Ag capsule-deficient mutants did not exhibit reduced virulence in a murine model of acute infection,in vitroresults indicate that the O-Ag capsule may function to modify the antigenic nature of the bacterial surface, warranting additional investigation of a potential role of the structure in pathogenesis.ĪBSTRACTDoes the age of a microbial cell affect its virulence factors? To our knowledge, this question has not been addressed previously, but the answer is of great relevance for chronic infections where microbial cells persist and age in hosts.Cryptococcus neoformansis an encapsulated human-pathogenic fungus notorious for causing chronic infections where cells of variable age persist in tissue. Furthermore, O-Ag capsule-deficient mutants produced exclusively phase I flagellin (FliC). Western blot analysis and confocal microscopy revealed that O-Ag capsule-deficient mutants demonstrate reduced resistance to killing by human serum. Loss of O-Ag capsule production did not alter bacterial growth or production of LPS. To test this hypothesis, O-Ag capsule-deficient mutants were constructed, and the loss of O-Ag capsular surface expression was confirmed through microscopy and immunoblotting. While much of thein vivoinnate immune resistance ofSalmonella entericaserovar Typhimurium is attributed to the high-molecular-weight LPS, we hypothesized that the O-Ag capsule may enhance this resistance by diminishing surface expression of pathogen-associated molecular patterns, such as flagella, and increasing resistance to host immune molecules. Previous studies on the O-Ag capsule of salmonellae have focused primarily on its role in bacterial surface attachment and chronic infection however, the potential effects of the O-Ag capsule on acute pathogenesis have yet to be investigated. Capsular polysaccharides are known virulence factors of many bacterial pathogens, facilitating evasion of immune recognition and systemic dissemination within the host. Such capsules are known as O-antigen (O-Ag) capsules, due to their high degree of similarity to the O-Ag of the lipopolysaccharide (LPSO-Ag). Structural Biology and Molecular Biophysics.Group IV polysaccharide capsules are common in enteric bacteria and have more recently been described in nontyphoidalSalmonellaspecies. We are part of the Laboratory of Molecular Biophysics at the University of Oxford. Our research focuses on developing methods for macromolecular crystallography (MX) to enable problems not previously accessible to structure solution to be tackled. This work currently includes studies on 100K and room temperature (RT) radiation damage and the analysis of liquid and crystalline samples by the tehnique of microPIXE (microbeam Proton Induced X-ray Emission). The group also solve protein structures, most recently of arylamine N-acetyltransferase from Mycobacterium tuberculosis.įor more information about the group please visit our "People" page hereĪbove is the cover of the special issue of the Journal of Synchrotron Radiation on X-ray Radiation Damage to Biological Crystalline Samples (March 2015). The image on the lower right shows the specific damage distribution (red and blue spheres) of the irradiated baterial protein-DNA complex CEsp1396I/DNA. The work and figure was produced by Charlie Bury. Introduction to Crystallographyįor an introduction into the method of X-ray crystallography please see this animation which Elspeth and Jonny helped to produce with Oxford Sparks. The British Crystallographic Association (BCA) is the UK national association for crystallograpy. It's main aims are the promotion of crystallography in research and the education of young people and others in the methods, possibilities and achievements of crystallographic science. Special Issue of JSR - In March 2015 a special issue of the Journal of Synchrotron Radiation on X-ray Radiation Damage to Biological Crystalline Samples was published. This issue was edited by Elspeth and Martin Weik and features papers by Charlie Bury and Garman Group Alumnus Markus Gerstel.Įlspeth in puerto Rico - The BioXFEL conference took place in Puerto Rico this year and Elspeth was in attendance.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |