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Immunostimulative effects of repeated inhalation exposure to microvesicle-bound endotoxin of Pantoea agglomerans
Jacek Dutkiewicz1, Czesława Skórska, Robert Burrell
1Department of Occupational Biohazards, Institute of Agricultural Medicine, Jaczewskiego 2, 20-090 Lublin, Poland. dutkiewi@galen.imw.lublin.pl
Abstract:
Rabbits exposed repeatedly to aerosols of endotoxin-containing microvesicles (ECMV) of the outer membrane of the Pantoea agglomerans strain isolated from airborne grain dust showed a large increase in the concentration of circulating cytokines: total interferon (IFN), interleukin-1 alpha (IL-1 alpha), and tumor necrosis factor alpha (TNF alpha). The increase was significantly higher compared to animals exposed to control saline (p < 0.001). Aerosol exposure to ECMV also induced the formation of specific precipitin antibodies and lymphocyte activation. The results indicate strong immunomodulative properties of ECMVs produced in nature by Pantoea agglomerans bacteria, and heavily contaminating organic dusts.
Insights
Exposure to Pantoea agglomerans microvesicles (ECMV) from airborne grain dust significantly increased circulating cytokines, including interferon (IFN), interleukin-1 alpha (IL-1 alpha), and tumor necrosis factor alpha (TNF alpha) in rabbits.
Area of Science:
- Immunology
- Microbiology
- Environmental Health
Background:
- Organic dusts, particularly from airborne grain, can contain bacterial components.
- Pantoea agglomerans is a bacterium found in natural environments and associated with organic dusts.
Purpose of the Study:
- To investigate the immunomodulatory effects of endotoxin-containing microvesicles (ECMV) from Pantoea agglomerans.
- To assess the immune response in rabbits following repeated aerosol exposure to ECMV.
Main Methods:
- Rabbits were exposed to aerosols of ECMV from Pantoea agglomerans.
- Control animals were exposed to saline.
- Measurements included circulating cytokines (IFN, IL-1 alpha, TNF alpha), precipitin antibodies, and lymphocyte activation.
Main Results:
- A significant increase in total interferon (IFN), interleukin-1 alpha (IL-1 alpha), and tumor necrosis factor alpha (TNF alpha) was observed in ECMV-exposed rabbits compared to controls (p < 0.001).
- Aerosolized ECMV exposure induced specific precipitin antibody formation.
- Lymphocyte activation was also noted in response to ECMV exposure.
Conclusions:
- ECMV from Pantoea agglomerans possess potent immunomodulatory properties.
- These findings highlight the role of bacterial microvesicles in organic dusts in modulating the immune system.
