Alveolar cell therapy with genetically modified bone marrow-derived stem cells.
Lead Research Organisation:
University College London
Department Name: Medicine
Abstract
Chronic lung diseases are extremely common. They cause destruction of the gas exchange surface of the lung (parenchyma) making patients progressively breathless until they reach respiratory failure and die. Current medical interventions are failing these patients, leading to a search for new treatments.
Stem cells are big news and it appears that the lung not only uses resident cells to affect repair after damage, but also recruits circulating stem cells from the bone marrow. These cells appear to change into lung cells after moving into the injured lung parenchyma. This may be a previously unknown mechanism by which the body repairs damaged organs. However, we also believe there are other bone marrow cells that exacerbate lung damage rather than repair it. We have two major goals:
1. To determine which bone marrow cells are responsible for lung repair.
2. To use gene therapy to make our chosen population of bone marrow stem cells produce a growth factor, enhancing lung repair.
We believe the combined expertise of scientists and clinicians at the Centre for Respiratory Disease (UCL) and the Haematopoietic Stem Cell Laboratory (CRUK) will lead to novel treatments for a wide range of debilitating diseases including emphysema and lung fibrosis.
Stem cells are big news and it appears that the lung not only uses resident cells to affect repair after damage, but also recruits circulating stem cells from the bone marrow. These cells appear to change into lung cells after moving into the injured lung parenchyma. This may be a previously unknown mechanism by which the body repairs damaged organs. However, we also believe there are other bone marrow cells that exacerbate lung damage rather than repair it. We have two major goals:
1. To determine which bone marrow cells are responsible for lung repair.
2. To use gene therapy to make our chosen population of bone marrow stem cells produce a growth factor, enhancing lung repair.
We believe the combined expertise of scientists and clinicians at the Centre for Respiratory Disease (UCL) and the Haematopoietic Stem Cell Laboratory (CRUK) will lead to novel treatments for a wide range of debilitating diseases including emphysema and lung fibrosis.
Technical Summary
Many common diseases of the gas exchange surface of the lung (the parenchyma) have no specific treatment but have a dreadful morbidity and mortality. The covert pathogenesis of these common conditions has contributed to the lack of satisfactory treatment options and poor outcomes. This proposal aims to examine the role of bone marrow-derived stem cells (BMSCs) in repairing acute parenchymal lung injury. We and others have recently shown that the lung not only uses resident cells to affect repair after injury, but also recruits circulating bone marrow-derived stem cells, from which lung cells are derived. We hypothesise that targeted therapy for acute lung injury could be performed based on the recruitment of a modified population of BMSCs that promote epithelial repair. We shall ascertain:
1. Which sub-population of BMSCs is responsible for lung repair by epithelial engraftment and establish which populations may exacerbate or cause lung injury.
2. Whether the genetic over-expression of keratinocyte growth factor in donor-derived epithelium, using modified lentiviruses, can improve repair.
We will accurately sort BMSCs into specific subgroups (SP, KLS, GMP, MSC-SSEA-1+) using fluorescence activated cell sorting analysis, and cell culture techniques. This fractionation is crucial to the proposal as several studies suggest that some bone marrow sub-populations may cause lung damage. The cell sub-populations will then be systemically delivered, with and without bleomycin-induced lung damage. Alveolar-engrafted donor cells will be identified using enhanced green fluorescence protein (eGFP) lineage marking or Y chromosome labelling, and the extent of lung engraftment and damage (fibrosis) will be assessed by measuring vascular leak (Evans blue technique) and collagen load (hydroxyproline content).
The project will then ascertain the efficiency and time course of viral gene expression in donor-derived alveolar cells using transduction with eGFP and the known epithelial mitogen keratinocyte growth factor (KGF). The sub-populations of transduced cells will then be delivered following bleomycin damage. These experiments will determine whether supplementing the circulating pool of stem cells, by injecting sub-populations of donor BMSCs, enhances repair of the alveolar epithelium and hence mitigates the lung toxicity of bleomycin. The effect of KGF expression on engraftment, lung morphology and inflammation will be examined over the course of a year after BMT.
We believe these experiments may lead to completely novel cell based therapy and a new means of delivering gene therapy to the lung, improving the treatment of currently intractable diseases.
1. Which sub-population of BMSCs is responsible for lung repair by epithelial engraftment and establish which populations may exacerbate or cause lung injury.
2. Whether the genetic over-expression of keratinocyte growth factor in donor-derived epithelium, using modified lentiviruses, can improve repair.
We will accurately sort BMSCs into specific subgroups (SP, KLS, GMP, MSC-SSEA-1+) using fluorescence activated cell sorting analysis, and cell culture techniques. This fractionation is crucial to the proposal as several studies suggest that some bone marrow sub-populations may cause lung damage. The cell sub-populations will then be systemically delivered, with and without bleomycin-induced lung damage. Alveolar-engrafted donor cells will be identified using enhanced green fluorescence protein (eGFP) lineage marking or Y chromosome labelling, and the extent of lung engraftment and damage (fibrosis) will be assessed by measuring vascular leak (Evans blue technique) and collagen load (hydroxyproline content).
The project will then ascertain the efficiency and time course of viral gene expression in donor-derived alveolar cells using transduction with eGFP and the known epithelial mitogen keratinocyte growth factor (KGF). The sub-populations of transduced cells will then be delivered following bleomycin damage. These experiments will determine whether supplementing the circulating pool of stem cells, by injecting sub-populations of donor BMSCs, enhances repair of the alveolar epithelium and hence mitigates the lung toxicity of bleomycin. The effect of KGF expression on engraftment, lung morphology and inflammation will be examined over the course of a year after BMT.
We believe these experiments may lead to completely novel cell based therapy and a new means of delivering gene therapy to the lung, improving the treatment of currently intractable diseases.