The Effect of O Antigen Loss on the Protein Composition and Inflammatory Response Elicited by Klebsiella pneumoniae

Klebsiella pneumoniae is a Gram-negative pathogen associated with numerous infections. Like all Gram-negative bacteria, K. pneumoniae naturally release outer membrane vesicles (OMVs) during all stages of cellular growth. OMVs are composed of the outer membrane components such as lipopolysaccharide (LPS) and outer membrane proteins and contain cytosolic and periplasmic proteins in the lumen. K. pneumoniae is often found to lack an O antigen. The absence of the O antigen has been reported to alter the protein content of the membrane which may further alter the immune response elicited by K. pneumoniae. Therefore the purpose of this study was to analyze the protein content and inflammatory responses of the cellular outer membrane (OM) and the secreted OMVs. A secondary goal of this study was to evaluate any changes to the membrane protein content due to O antigen loss and determine if the loss of the O antigen influences the inflammatory response. This study demonstrated that the cellular OM and OMVs have distinct protein profiles as well as inflammatory responses. OMVs were highly enriched in outer membrane proteins compared to the cellular OM and had a significantly stronger inflammatory response. The protein content of the OM and OMVs were further modified by the absence of the O antigen from the outer membrane. Although there were no significant differences seen in the wild type and O antigen deficient OM inflammatory responses, the loss of the O antigen resulted in OMVs that produced a significantly stronger IL-6 response.

Grantor dc:publisher

UNF Digital Commons

Year dc:date

2015

Author dc:creator

• Cahill, Bethaney

• Thesis; University of North Florida; UNF; Dissertations
• Academic -- UNF -- Master of Science in Biology; Dissertations
• Academic -- UNF -- Biology; Bacteria; pathogens; lipopolysaccharide; vesicles; proteins; inflammatory response
• Immunology and Infectious Disease
• Life Sciences
• Molecular Biology
• Pathogenic Microbiology

Repository record dc:identifier

https://digitalcommons.unf.edu/etd/553

OAI identifier oai:identifier

oai:digitalcommons.unf.edu:etd-1583