Fibrocytes in Chronic Lung Disease Theses

The focus of this thesis was the role of fibrocytes in chronic lung disease. These bone marrow derived cells have been identified in the lung and the circulation in patient samples and animal models of lung injury. However, the precise mechanistic role of the fibrocyte is still to be elucidated.

Live assessment of lung changes in animal models of chronic lung disease allows for real time observation of changes, and gives a readout which can be translated to humans who undergo similar tests. In this thesis, we adapted an existing model of lung injury, and delivered a discrete treatment to a single lung lobe while monitoring its successful delivery.

I also developed a robust system to examine the relationship between fibrocyte response, and cytokine expression previously identified in chronic lung disease. We found a connection between cytokine expression and fibrocyte mobilisation. Our model showed that fibrocyte mobilisation in the presence of existing lung injury does not improve and rather can worsen existing lung injury. This was a significant finding as it confirms the role of the fibrocyte as a participator or conductor in fibrogenesis and it suggests that this cell may play a role in the development of chronic lung diseases.

Finally, we contributed to the ongoing characterisation of the fibrocyte as a prospective biomarker. We confirmed the cell’s identity by characterising it by its known markers and biological characteristics. We also identified the presence of this cell in chronic lung disease and linked its presence to disease progression.