Honors Program
Honors Program: Embargoed Theses
First Advisor
Michael A. Herman
Second Advisor
Brian A. Couch
Date of this Version
Spring 3-31-2025
Document Type
Thesis
Citation
Song, M. 2025. Involvement of Putative Membrane Raft Proteins in Caenorhabditis elegans Innate Immune Response to Pathogenic Stenotrophomonas maltophilia. Undergraduate Honors Thesis. University of Nebraska-Lincoln
Abstract
Stenotrophomonas maltophilia is a gram-negative, multidrug-resistant bacterium and emerging opportunistic pathogen that infects susceptible immunocompromised. Caenorhabditis elegans is an attractive tool for examining host-pathogen interactions and pathogenicity mechanisms of S. maltophilia as members of the Stenotrophomonas genus are natural food sources and gut microbiome components. Genes differentially expressed in C. elegans’ innate immune response to S. maltophilia were previously identified through a transcriptomic analysis, three of which, irg-8, dod-19, and B0024.4, encode membrane raft proteins. These genes were upregulated during the pathogenic response, and loss-of-function mutant strains showed increased susceptibility. All three genes share significant sequence similarity and irg-8 and dod-19 are directly adjacent in the genome. Furthermore, each of these genes is required for proper expression of sysm-1::GFP, an effector of the p38 PMK-1 MAPK stress response pathway, suggesting they play a role in pathway activation. Based on this information, we chose these genes for further characterization. CRISPR-Cas9 was used to generate fluorescent tags as well as double and triple loss-of-function mutants, and characterization has yielded interesting and novel insights into their expression, localization, and functional involvement, including specificity during S. maltophilia infection compared to other bacterial pathogens.
Comments
Copyright Minjae Song 2025.