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Biology Colloquium - Dr. Kirk Jensen

PostPosted: Mon Oct 03, 2016 8:58 am
by cdouglas

Department of Biology
presents

Dr. Kirk Jensen
School of Natural Sciences, University of California, Merced, CA
Chair of Graduate Admissions, Quantitative Systems Biology

“Toxoplasma gondii - a parasite’s understanding of the adaptive immune system”


Friday, October 7, 2016
3:00 PM
Science 2, Room 109


ABSTRACT. Our lab studies host-pathogen interactions using the widespread parasite of mammals and birds, Toxoplasma gondii. It is a very clever parasite, and is able to achieve chronic infection in the brains of most hosts, including 2 billion humans. Toxoplasma accomplishes this feat using specialized virulence factors it secretes into host cells, which can manipulate signaling pathways and immune defense mechanisms. Recently, we have noted a battle that takes place between Toxoplasma and a specific cell type of the adaptive immune system, the CD8 T cell. This immune cell is required for host immunity to most intracellular pathogens, however, Toxoplasma can turn “on” or “off” the activation of this immune cell. It is likely Toxoplasma has evolved to manipulate this immune cell to achieve chronic infection so it can complete its life cycle. By studying this particular host-parasite interaction, insights might be gained to better activate these cells during an infection. A feat which has to happen should we ever hope to develop a protective vaccine for human parasitic pathogens.

Figure. An immunofluorescence picture of Toxoplasma gondii (twelve dim green parasites) inside a human fibroblast cell. The red dots indicate a key Toxoplasma virulence factor, Rhoptry protein 5 (red), used to manipulate the immune system. The large blue blob is the infected human cell’s nuclear DNA stained with Hoechst dye (bue), the nuclei of Toxoplasma can also be seen.



For further information: http://www.csufresno.edu/biology or phone 278-2001. If you need a disability-related accommodation or wheelchair access information, please contact Lindasue Garner at the Department of Biology @ 278-2001 or e-mail lgarner@csufresno.edu (at least one week in advance of event).