Related Experiment Videos
An in vitro model system to evaluate pulmonary macrophage, endothelial cell, and neutrophil interactions
S D Sharma1, M A Breider, T W Olchowy
1Dept. of Pathobiology, Coll. Vet. Med., Univ. Tennessee, Knoxville 37996-4500.
Abstract:
Pasteurella haemolytica, the cause of fibrinous pleuropneumonia in cattle, produces extensive microvascular endothelial cell (EC) damage. We have developed an in vitro model system to study the inflammatory process of this disease involving the interaction of pulmonary alveolar macrophages (AM), neutrophils (PMN), and EC. Bovine EC are grown to confluency in 24 well tissue culture plates. To mimic the vascular component, 10(6) PMN are later added to the EC monolayers. Bovine AM are plated onto millicell inserts and placed into the wells containing EC and PMN. The millicell insert serves as a semi-permeable barrier between AM and EC, allowing the exchange of only diffusible material. Preliminary work demonstrates that P. haemolytica stimulated AM resulted in EC damage presumably due to both soluble lipopolysaccharide and AM secreted products.
Insights
This study models bovine lung inflammation caused by Pasteurella haemolytica. Macrophages and neutrophils interacting with endothelial cells show damage from bacterial products.
Area of Science:
- Veterinary Pathology
- Cell Biology
- Immunology
Background:
- Pasteurella haemolytica causes significant lung damage in cattle.
- Microvascular endothelial cell (EC) injury is a key feature of this disease.
- Understanding the cellular interactions is crucial for disease management.
Purpose of the Study:
- To establish an in vitro model simulating bovine pleuropneumonia.
- To investigate the roles of pulmonary alveolar macrophages (AM) and neutrophils (PMN) in EC damage.
- To identify the inflammatory mediators involved in Pasteurella haemolytica-induced lung injury.
Main Methods:
- Developed a co-culture system with bovine EC, AM, and PMN.
- Utilized a semi-permeable membrane to allow diffusion between AM and EC.
- Stimulated AM with P. haemolytica to observe inflammatory responses.
Main Results:
- The in vitro model successfully replicated aspects of bovine lung inflammation.
- P. haemolytica-stimulated AM induced damage to the EC monolayers.
- Both soluble lipopolysaccharide and AM-secreted factors contributed to EC injury.
Conclusions:
- The developed model is effective for studying bovine pleuropneumonia pathogenesis.
- Macrophages play a critical role in mediating endothelial cell damage.
- Bacterial components and macrophage-derived factors are key drivers of inflammation.