Five Extracellular Proteins of Group A Streptococcus: Antigenicity and Gene Expression
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Authors
Stenseth, Elisha
Advisor
Gerald Shields
Sam Alvey
Sean Reid
Sam Alvey
Sean Reid
Editor
Date of Issue
2002-04-01
Subject Keywords
Publisher
Citation
Series/Report No.
item.page.identifier
Title
Five Extracellular Proteins of Group A Streptococcus: Antigenicity and Gene Expression
Other Titles
Type
thesis
Description
Abstract
Five genes that encode novel extracellular proteins were previously identified through the genomic analysis of four Group A Streptococcus strains (serotypes Ml, M3, M5, and M18) (Reid et al., 2001). Four of the five proteins have an LPXTG amino acid motif at the carboxyterminus, a motif that covalently links extracellular proteins to the cell surface in many gram-positive pathogens. All of the genes encode proteins with a secretion signal sequence at the aminoterminus. In vivo expression was demonstrated with Western blots using sera obtained from 80 patients with invasive infections, non-invasive skin infections, pharyngitis, and acute rheumatic fever. Real-time reverse transcriptase-PCR analysis of gene transcription showed that the amount and time of maximal gene transcript varies for the five genes among the Ml, M3, and M18 serotypes. With the use of flow cytometry, surface expression was confirmed for proteins for which antibodies were available. These results indicate that further exploration of these genes as potential vaccine candidates is warranted.
Sponsors
Degree Awarded
Bachelor's
Semester
Spring
Department
Life & Environmental Sciences