The production of ROS (reactive oxygen species) in response to pathogen detection is a rapid, nonspecific response that is evolutionarily conserved from nematodes to humans. ROS serve as direct and indirect effectors of innate and adaptive immunity. In Caenorhabditis elegans, a ROS burst is observed during infection and is mediated by the dual oxidase BLI-3, which produces H2O2. RNAi (RNA interference) to reduce the amount of BLI-3 results in a significant increase in susceptibility to pathogens, suggesting BLI-3 has a role in the immune response. However, H2O2 by itself is not a potent antimicrobial and in other systems is converted to a more potent oxidant by an affiliated peroxidase. During my work, I have characterized a group of previously unstudied peroxidases in C. elegans and determined their involvement in the host immune response to Enterococcus faecalis. In particular, I focused on SKPO-1 (ShkT-containing peroxidase) and how it contributes to the host immune response with respect to BLI-3.
By RNAi and skpo-1 mutant analysis, I determined that SKPO-1 is involved in the host immune response during E. faecalis infection. By tissue-specific RNAi, I determined that SKPO-1 is functionally active in the hypodermis and required for wild type resistance to infection. Additionally, by immunohistochemistry, I observed that SKPO-1 is only expressed in the hypodermis and that its protein levels do not change in response to E. faecalis. In support of SKPO-1 acting as a peroxidase, I observed a significant increase in H2O2 levels when expression of the gene was reduced by RNAi. The increased H2O2 was observed only during infection and was BLI-3-dependent. Thus, I have characterized a likely BLI-3/SKPO-1 system, potentially similar to the oxidative burst systems present in higher eukaryotes.
","abstract_html":"<p>The production of ROS (reactive oxygen species) in response to pathogen detection is a rapid, nonspecific response that is evolutionarily conserved from nematodes to humans. ROS serve as direct and indirect effectors of innate and adaptive immunity. In <em>Caenorhabditis elegans</em>, a ROS burst is observed during infection and is mediated by the dual oxidase BLI-3, which produces H<sub>2</sub>O<sub>2</sub>. RNAi (RNA interference) to reduce the amount of BLI-3 results in a significant increase in susceptibility to pathogens, suggesting BLI-3 has a role in the immune response. However, H<sub>2</sub>O<sub>2</sub> by itself is not a potent antimicrobial and in other systems is converted to a more potent oxidant by an affiliated peroxidase. During my work, I have characterized a group of previously unstudied peroxidases in <em>C. elegans </em>and determined their involvement in the host immune response to <em>Enterococcus faecalis</em>. In particular, I focused on SKPO-1 (ShkT-containing peroxidase) and how it contributes to the host immune response with respect to BLI-3.</p> <p>By RNAi and <em>skpo-1</em> mutant analysis, I determined that SKPO-1 is involved in the host immune response during <em>E. faecalis</em> infection. By tissue-specific RNAi, I determined that SKPO-1 is functionally active in the hypodermis and required for wild type resistance to infection. Additionally, by immunohistochemistry, I observed that SKPO-1 is only expressed in the hypodermis and that its protein levels do not change in response to <em>E. faecalis</em>. In support of SKPO-1 acting as a peroxidase, I observed a significant increase in H<sub>2</sub>O<sub>2</sub> levels when expression of the gene was reduced by RNAi. The increased H<sub>2</sub>O<sub>2 </sub>was observed only during infection and was BLI-3-dependent. Thus, I have characterized a likely BLI-3/SKPO-1 system, potentially similar to the oxidative burst systems present in higher eukaryotes.</p>","abstract_has_math":false,"creators":["Tiller, George R"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation (PhD)","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Danielle A. Garsin","Joseph Alcorn","Steve Norris"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-08-01T07:00:00Z","date_published":"2014-08-01T07:00:00Z","updated_at":"2026-07-24T05:50:16Z","subjects":["Peroxidase","SKPO-1","ROS","innate immunity","E. faecalis","C. elegans","hypodermis","Immunity","Medicine and Health Sciences","Molecular Genetics","Pathogenic Microbiology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.library.tmc.edu/utgsbs_dissertations/483","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Danielle A. 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ROS serve as direct and indirect effectors of innate and adaptive immunity. In Caenorhabditis elegans, a ROS burst is observed during infection and is mediated by the dual oxidase BLI-3, which produces H2O2. RNAi (RNA interference) to reduce the amount of BLI-3 results in a significant increase in susceptibility to pathogens, suggesting BLI-3 has a role in the immune response. However, H2O2 by itself is not a potent antimicrobial and in other systems is converted to a more potent oxidant by an affiliated peroxidase. During my work, I have characterized a group of previously unstudied peroxidases in C. elegans and determined their involvement in the host immune response to Enterococcus faecalis. In particular, I focused on SKPO-1 (ShkT-containing peroxidase) and how it contributes to the host immune response with respect to BLI-3.
By RNAi and skpo-1 mutant analysis, I determined that SKPO-1 is involved in the host immune response during E. faecalis infection. By tissue-specific RNAi, I determined that SKPO-1 is functionally active in the hypodermis and required for wild type resistance to infection. Additionally, by immunohistochemistry, I observed that SKPO-1 is only expressed in the hypodermis and that its protein levels do not change in response to E. faecalis. In support of SKPO-1 acting as a peroxidase, I observed a significant increase in H2O2 levels when expression of the gene was reduced by RNAi. The increased H2O2 was observed only during infection and was BLI-3-dependent. Thus, I have characterized a likely BLI-3/SKPO-1 system, potentially similar to the oxidative burst systems present in higher eukaryotes.
"]},{"key":"dc:title","label":"Title","values":["Potential Roles of Peroxidases In Caenorhabditis Elegans Innate Immunity"]}]}],"canonical_facts":{"dc:contributor":["Danielle A. Garsin","Joseph Alcorn","Steve Norris"],"dc:creator":["Tiller, George R"],"dc:date.available":["2014-07-25T07:00:00Z"],"dc:description.abstract":["The production of ROS (reactive oxygen species) in response to pathogen detection is a rapid, nonspecific response that is evolutionarily conserved from nematodes to humans. ROS serve as direct and indirect effectors of innate and adaptive immunity. In Caenorhabditis elegans, a ROS burst is observed during infection and is mediated by the dual oxidase BLI-3, which produces H2O2. RNAi (RNA interference) to reduce the amount of BLI-3 results in a significant increase in susceptibility to pathogens, suggesting BLI-3 has a role in the immune response. However, H2O2 by itself is not a potent antimicrobial and in other systems is converted to a more potent oxidant by an affiliated peroxidase. During my work, I have characterized a group of previously unstudied peroxidases in C. elegans and determined their involvement in the host immune response to Enterococcus faecalis. In particular, I focused on SKPO-1 (ShkT-containing peroxidase) and how it contributes to the host immune response with respect to BLI-3.
By RNAi and skpo-1 mutant analysis, I determined that SKPO-1 is involved in the host immune response during E. faecalis infection. By tissue-specific RNAi, I determined that SKPO-1 is functionally active in the hypodermis and required for wild type resistance to infection. Additionally, by immunohistochemistry, I observed that SKPO-1 is only expressed in the hypodermis and that its protein levels do not change in response to E. faecalis. In support of SKPO-1 acting as a peroxidase, I observed a significant increase in H2O2 levels when expression of the gene was reduced by RNAi. The increased H2O2 was observed only during infection and was BLI-3-dependent. Thus, I have characterized a likely BLI-3/SKPO-1 system, potentially similar to the oxidative burst systems present in higher eukaryotes.
"],"dc:identifier":["https://digitalcommons.library.tmc.edu/utgsbs_dissertations/483"],"dc:subject":["Peroxidase","SKPO-1","ROS","innate immunity","E. faecalis","C. elegans","hypodermis","Immunity","Medicine and Health Sciences","Molecular Genetics","Pathogenic Microbiology"],"dc:title":["Potential Roles of Peroxidases In Caenorhabditis Elegans Innate Immunity"],"thesis:degree_level":["Dissertation (PhD)"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T05:50:16Z"}