Date of Award

January 2022

Document Type


Degree Name

Master of Science (MS)


Biomedical Sciences

First Advisor

Matthew Nilles


Yersinia pestis, the causative agent of plague, secretes a set of virulence proteins called Yops when in contact with eukaryotic cells. A subset of these Yops is translocated directly into the cytosol of the host eukaryotic cells by the type III secretion system. Using a protein tag-based reporter system, this study is focused on the translocation of these Yops into the cytosol of canine derived cell lines: MDCK and DH82. The MDCK cell line is a canine derived epithelial cell line, and the DH82 cell line is a canine derived monocyte cell line. The reporter system uses a phosphorylatable peptide tag, called the Elk tag. Translocation of an Elk-tagged protein into eukaryotic cells results in host cell protein kinase-dependent phosphorylation that can be detected by phosphospecific antibodies. Canines are typically considered resistant to plague infections. Previous work has shown the requirement of receptor FPR1 for Yops translocation into mouse and human cells. Therefore, translocation of Yops into canine cells was examined because a lack of Yops translocation could explain plague resistance in canines. The translocation of Elk-tagged YopE was observed in the canine derived cell lines MDCK and DH82. This data suggests that there may be an underlying immune response allowing canines infected with Yersinia pestis to recover.