Date of Award
2007
Degree Type
Thesis
Degree Name
Master of Science
Program
Microbiology and Immunology
Supervisor
Dr. John McCormick
Abstract
Streptococcus pyogenes is a Gram-positive bacterial pathogen associated with an extraordinary range of human infections. Streptococcal pyrogenic exotoxins are key secreted virulence factors secreted by S. pyogenes that function as superantigens to cause massive T cell activation by cross linking T cell receptors on T cells, and MHC class II molecules on antigen presenting cells. Superantigens can engage MHC class II in two radically divergent ways. One interface is of relative high-affinity, requires zinc, and is present on most streptococcal superantigens. A second interface present on many staphylococcal superantigens is of relative low-affinity, does not require zinc, but the presence of this interface on streptococcal superantigens is controversial. Herein, mutagenesis analysis of multiple streptococcal superantigens, demonstrates the low-affinity MHC class Il binding interface is likely present on all streptococcal superantigens. A complete functional map of this interface on the streptococcal superantigen SpeC provides a molecular basis for MHC class II discrimination by streptococcal superantigens.
Recommended Citation
Kasper, Katherine J., "Functional Characterization of Streptococcal Superantigen Low-Affinity MHC Class II Binding Interfaces" (2007). Digitized Theses. 5128.
https://ir.lib.uwo.ca/digitizedtheses/5128