Volume: 1, 2022
1st International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: A013
DOI: https://doi.org/10.24326/ICDSUPL1.A013
Published online: 26 April 2022
ICDSUPL, 1, A013 (2022)
Pseudomonas aeruginosa exotoxin A modulates Galleria mellonella cellular immune response
Bartłomiej Iwański1*, Aleksandra Bartkowska1, Monika Koziej1, Mariola Andrejko1
1Department of Immunobiology, Faculty of Biology and Biotechnology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland
* Corresponding author: iwanski.bartlomiej11@wp.pl
Abstract
The cellular immune response of the greater wax moth Galleria mellonella to immunization with Pseudomonas aeruginosa exotoxin A was investigated. Exotoxin A (exoA) is considered one of the most dangerous virulence factors of P. aeruginosa. This ADP-ribosyltransferase is responsible mainly for protein inhibition and is cytotoxic towards mammalian white blood cells. G. mellonella larvae were chosen as a model organism due to the high degree of similarity between insect and mammalian innate immune response mechanisms. The insects were challenged with an experimentally established sublethal dose of exoA, and the hemolymph samples were collected 1, 4, 8, 15, 18, and 24 hours after injection; then, hemocyte parameters were assessed. A statistically significant decrease in the total hemocyte count (THC) and changes in the differential hemocyte count (DHC), namely granulocytes and plasmatocytes, were observed 8 and 15 hours after the challenge. In turn, no statistically significant changes were observed in the number of spherulocytes and oenocytoides. Further analyses involving fluorescent staining with a mixture of propidium iodide and Hoechst 33342 revealed that cells collected from the exoA-challenged larvae 8 and 15 hours after the immunization exhibited severe changes, i.e. cytoplasm vacuolization, chromatin condensation, and membrane blebbing. These features are characteristic for apoptotic and autophagic cell death. These changes correlated well with changes in the hemocytogram, which may suggest that P. aeruginosa exotoxin A induces apoptotic changes in insect hemocytes. Our results, which clearly indicate involvement of exoA in overcoming insect cellular immune response, will help in understanding the role of exotoxin A during Pseudomonas aeruginosa infections not only in insects but also in mammals, including humans.
How to cite
B. Iwański, A. Bartkowska, M. Koziej, M. Andrejko, 2022. Pseudomonas aeruginosa exotoxin A modulates Galleria mellonella cellular immune response. In: 1st International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL1/A013