Stx-2 is a major contributor to the pathogenesis of Escherichia coli 0157:H7. Prior reports suggest that Stx-2 increases necrosis and apoptosis of a variety of host cells including those of endothelial origin as well as immune cells such as neutrophils (156). However, the role Stx-2 plays in delayed apoptosis of neutrophils is not fully understood given that previous studies have shown conflicting results (118, 51). The process of apoptosis is mediated by the Bcl-2 protein family (2, 46, 226). The purpose of this research was to define the molecular mechanisms of Stx-2 and Bcl-2 protein family interactions. These studies examined the binding of Stx-2 to select Bcl-2 family proteins, and outlined the effects that Stx-2 and a newly generated mutant of Stx-2 have on neutrophil apoptosis and necrosis rates as well as on caspase-8 and caspase-9 activation. Stx-2 did not bind to the select Bcl-2 family proteins examined nor did it consistently show decreased apoptosis rates in neutrophils. The mechanisms behind Stx-2-induced neutrophil apoptosis potentially involved the endoplasmic reticulum (ER) stress response and/or interactions with other Bcl-2 family members such as Bak at the mitochondrial membrane therefore inducing mitochondrial membrane permeabilization (MMP) and its downstream effects.
","abstract_html":"<p>Stx-2 is a major contributor to the pathogenesis of Escherichia coli 0157:H7. Prior reports suggest that Stx-2 increases necrosis and apoptosis of a variety of host cells including those of endothelial origin as well as immune cells such as neutrophils (156). However, the role Stx-2 plays in delayed apoptosis of neutrophils is not fully understood given that previous studies have shown conflicting results (118, 51). The process of apoptosis is mediated by the Bcl-2 protein family (2, 46, 226). The purpose of this research was to define the molecular mechanisms of Stx-2 and Bcl-2 protein family interactions. These studies examined the binding of Stx-2 to select Bcl-2 family proteins, and outlined the effects that Stx-2 and a newly generated mutant of Stx-2 have on neutrophil apoptosis and necrosis rates as well as on caspase-8 and caspase-9 activation. Stx-2 did not bind to the select Bcl-2 family proteins examined nor did it consistently show decreased apoptosis rates in neutrophils. The mechanisms behind Stx-2-induced neutrophil apoptosis potentially involved the endoplasmic reticulum (ER) stress response and/or interactions with other Bcl-2 family members such as Bak at the mitochondrial membrane therefore inducing mitochondrial membrane permeabilization (MMP) and its downstream effects.</p>","abstract_has_math":false,"creators":["Jeffrey, Lia K"],"institution":null,"degree_name":"Doctor of Philosophy","degree_level":"Dissertation","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Frank Rodgers"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-01-01T08:00:00Z","date_published":"2013-01-01T08:00:00Z","updated_at":"2026-07-24T05:22:42Z","subjects":["Biology","Microbiology","Cell","Molecular"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholars.unh.edu/dissertation/728","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Frank Rodgers"]},{"key":"dc:creator","label":"Author","values":["Jeffrey, Lia K"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biology","Microbiology","Cell","Molecular"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholars.unh.edu/dissertation/728"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Stx-2 is a major contributor to the pathogenesis of Escherichia coli 0157:H7. Prior reports suggest that Stx-2 increases necrosis and apoptosis of a variety of host cells including those of endothelial origin as well as immune cells such as neutrophils (156). However, the role Stx-2 plays in delayed apoptosis of neutrophils is not fully understood given that previous studies have shown conflicting results (118, 51). The process of apoptosis is mediated by the Bcl-2 protein family (2, 46, 226). The purpose of this research was to define the molecular mechanisms of Stx-2 and Bcl-2 protein family interactions. These studies examined the binding of Stx-2 to select Bcl-2 family proteins, and outlined the effects that Stx-2 and a newly generated mutant of Stx-2 have on neutrophil apoptosis and necrosis rates as well as on caspase-8 and caspase-9 activation. Stx-2 did not bind to the select Bcl-2 family proteins examined nor did it consistently show decreased apoptosis rates in neutrophils. The mechanisms behind Stx-2-induced neutrophil apoptosis potentially involved the endoplasmic reticulum (ER) stress response and/or interactions with other Bcl-2 family members such as Bak at the mitochondrial membrane therefore inducing mitochondrial membrane permeabilization (MMP) and its downstream effects.
"]},{"key":"dc:title","label":"Title","values":["Interactions of shiga-like toxin-2 (Stx-2) from Escherichia coli O157:H7 and the Bcl-2 family of proteins during host cell programmed cell death"]}]}],"canonical_facts":{"dc:contributor":["Frank Rodgers"],"dc:creator":["Jeffrey, Lia K"],"dc:description.abstract":["Stx-2 is a major contributor to the pathogenesis of Escherichia coli 0157:H7. Prior reports suggest that Stx-2 increases necrosis and apoptosis of a variety of host cells including those of endothelial origin as well as immune cells such as neutrophils (156). However, the role Stx-2 plays in delayed apoptosis of neutrophils is not fully understood given that previous studies have shown conflicting results (118, 51). The process of apoptosis is mediated by the Bcl-2 protein family (2, 46, 226). The purpose of this research was to define the molecular mechanisms of Stx-2 and Bcl-2 protein family interactions. These studies examined the binding of Stx-2 to select Bcl-2 family proteins, and outlined the effects that Stx-2 and a newly generated mutant of Stx-2 have on neutrophil apoptosis and necrosis rates as well as on caspase-8 and caspase-9 activation. Stx-2 did not bind to the select Bcl-2 family proteins examined nor did it consistently show decreased apoptosis rates in neutrophils. The mechanisms behind Stx-2-induced neutrophil apoptosis potentially involved the endoplasmic reticulum (ER) stress response and/or interactions with other Bcl-2 family members such as Bak at the mitochondrial membrane therefore inducing mitochondrial membrane permeabilization (MMP) and its downstream effects.
"],"dc:identifier":["https://scholars.unh.edu/dissertation/728"],"dc:subject":["Biology","Microbiology","Cell","Molecular"],"dc:title":["Interactions of shiga-like toxin-2 (Stx-2) from Escherichia coli O157:H7 and the Bcl-2 family of proteins during host cell programmed cell death"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy"]},"updated_at":"2026-07-24T05:22:42Z"}