Date Presented

Spring 4-1-2007

Document Type


Degree Name

Bachelor of Science



First Advisor

Allison Jablonski

Second Advisor

William Lokar

Third Advisor

Nancy E. Cowden


Francisella tularensis, the intracellular pathogen that causes tularemia, was investigated to determine how it infects and replicates within mammalian hepatocytes. To date, it has been shown that hepatocytes can be infected by F. tularensis and that this causes considerable change in the protein phosphorylation state of several vital signaling molecules within the host cell. Protein kinase pathways can be mapped as signatures of infection. Hepatocytes tend to be susceptible to infection by F. tularensis, thus stimulating internal signaling. The Francisella strains used were selected with the goal of producing a model that can be used to elucidate the cell signaling pathways of cells infected by F. tularensis. Proteins from HepG2 human hepatocyte cells infected with F. novicida, F. Live Vaccine Strain (LVS) and F. philomiragia were separated by gel electrophoresis, and then examined through Western blotting to assay changes in protein kinase activation. Previous analysis has shown NF-kB and MAPK family member p38 are highly activated after infection. In this study, we examined activation of NF-kB and the protein kinases Src and Pyk2. Phospho-specific antibodies were also used as indicators of the presence of phosphorylated NF-kB, Src and Pyk2. Results from this study will be used to determine the pathways potentially activated during and after infection in the human liver in the event F. tularensis is used during a bioweapons attack.