PhD Scientific Days 2024

Poster Session F - Molecular Medicine 3.

Associative Immune Memory Formation in Caenorhabditis elegans Under Pathogenic Stress

Text of the abstract

Pseudomonas aeruginosa (PA) is an opportunistic human pathogen causing severe infections in immune deficient patients. Caenorhabditis elegans, a bacteriovore microscopic nematode co-evolving with pathogenic bacteria is an appropriate model organism of host-pathogen interactions. Moreover, mammals and C. elegans share major innate immune response pathways, which provides valuable insights into infection mechanisms and potential therapies. Our aim is to investigate how infection and pathogen-associated olfactory cues affect the innate immune response and whether they form an olfactory immune memory in C. elegans. To this end, young adult worms were kept on infectious PA bacterial lawn or were treated with the odor of PA to monitor the expression of immune response genes. A recovery period was provided post-infection, followed by a re-encounter of PA odor to examine transcriptional immune memory formation and retrieval. RNA was isolated from synchronized populations, and RT-qPCR was used to measure mRNA levels. Among genes involved in different signalling routes of the immune response, irg-5 and sysm-1 showed significant induction upon infection, whereas mRNA level of lys-7 and clec-190 were significantly reduced upon both PA and odor cues. Our current experiments aim to exclude the possibility of pathogenic bacterial remnants after recovery and test whether re-exposure solely to PA olfactory cues elicit a transcriptional immune response in intestinal cells. An olfactory immune response may suggest a functional link between the nervous system and the intestinal immune cells, which may promote host protection during infection. This experiment is funded by the Hungarian Science Foundation (OTKA K147337).