Investigation of the Immunogenicity and Specificity of the Transferrin Binding Proteins from Bovine Pathogenic Bacteria

Through trying to survive and proliferate within their hosts, pathogens have developed creative mechanisms of acquiring iron. A nutrient required for survival by most organisms, iron is both highly sought and jealously guarded. Hosts sequester iron using iron-binding proteins. These iron sinks keep the extracellular concentration of free iron at a level that does not support microbial proliferation. Transferrin is a bilobal iron carrying protein found in the blood and cerebrospinal fluid, and on mucosal surfaces. It is targeted by a number of microbial transferrin binding proteins and siderophores. This thesis focuses on one of the best-studied bacterial transferrin receptors, which consists of the transporter TbpA and its associated surface lipoprotein TbpB. TbpA and TbpB have been studied for years as potential vaccine antigens. Recently, mutants of TbpB that do not bind transferrin have been shown to provide improved protection against infection compared to wild-type TbpB. In this thesis, I develop a method for rapidly screening TbpB mutants, measure loss of affinity for multiple mutations, and investigate the effectiveness of a mutant in generating transferrin blocking antibodies. Furthermore, I investigate multiple methods of measuring binding specificity in Tbp-transferrin interactions in order to lay the groundwork for identifying functionally important residues in Tbps, and for designing improved animal models of infection.

Department dc:contributor.department

Biochemistry

Year dc:date.issued

2019

Author dc:creator

• Pogoutse, Anastassia Igorevna

Advisor dc:contributor.advisor

• Moraes, Trevor F

• bacterial membrane proteins
• host-pathogen interactions
• nutritional immunity
• protein-protein interactions

Handle dc:identifier.uri

http://hdl.handle.net/1807/108210

OAI identifier oai:identifier

oai:utoronto.scholaris.ca:1807/108210