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Published on: May 4, 2018
Comparative study of immune responses elicited by outer membrane vesicles of different Pseudomonas aeruginosa strains
Fereshteh Satarian1, Taher Nejadsattari1, Farzam Vaziri2
1Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Background:
Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic mucosal human pathogen that naturally releases outer membrane vesicles (OMVs) in different environments, as do other Gram-negative bacteria. The intestinal tract infections caused by P. aeruginosa increase the risk of respiratory infections and mortality of other diseases related to gut infections. Therefore, in this study, we attempted to investigate toll-like receptor (TLR) signaling pathways and immune response profiles of human colon adenocarcinoma (Caco2) cell line exposed to the OMVs of three different P. aeruginosa strains (i.e., antibiotic-susceptible, multi-drug resistant (MDR), and standard lab ATCC 17933).
Materials And Methods:
Real-time quantitative reverse transcription PCR array was carried out to determine mRNA expression in 84 TLRs signaling pathway genes, and the production of specific cytokines was measured by ELISA.
Results:
OMVs of different strains could induce unique changes in regulating TLRs signaling pathways, such that there were remarkable differences in pro-inflammatory effects and anti-inflammatory responses among the three strains.
Conclusion:
The more complete immune responses observed through the MAMPs caused by MDR strain OMVs interactions with Caco2 lead us to the conclusion that the use of MDR or cystic fibrosis strain OMVs for better known the host immune responses seems preferable.
Insights
Outer membrane vesicles (OMVs) from Pseudomonas aeruginosa strains trigger distinct toll-like receptor (TLR) signaling pathways and immune responses in Caco2 cells. Multi-drug resistant (MDR) strain OMVs elicit more comprehensive immune reactions, suggesting their utility in studying host immunity.
Area of Science:
- Microbiology
- Immunology
- Cell Biology
Background:
- Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen releasing outer membrane vesicles (OMVs).
- P. aeruginosa gut infections heighten risks for respiratory issues and mortality.
- Investigating P. aeruginosa OMVs' impact on human colon cells (Caco2) is crucial for understanding host-pathogen interactions.
Purpose of the Study:
- To explore toll-like receptor (TLR) signaling pathways and immune responses in Caco2 cells upon exposure to OMVs from three distinct P. aeruginosa strains.
- To compare the effects of OMVs from antibiotic-susceptible, multi-drug resistant (MDR), and standard lab strains on Caco2 cells.
Main Methods:
- Real-time quantitative reverse transcription PCR array to analyze mRNA expression of 84 TLR signaling pathway genes.
- Enzyme-Linked Immunosorbent Assay (ELISA) to quantify the production of specific cytokines.
Main Results:
- OMVs from different P. aeruginosa strains induced unique alterations in TLR signaling pathway regulation.
- Significant variations were observed in pro-inflammatory and anti-inflammatory responses among the three tested strains.
- MDR strain OMVs demonstrated a more complete induction of immune responses via MAMPs interaction with Caco2 cells.
Conclusions:
- The interaction of MDR strain OMVs with Caco2 cells results in more complete immune responses.
- Utilizing OMVs from MDR or cystic fibrosis strains of P. aeruginosa is recommended for a deeper understanding of host immune responses.
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