A toxicology study of Csf2ra complementation and pulmonary macrophage transplantation therapy of hereditary PAP in mice.

Pulmonary macrophage transplantation (PMT) is a gene and cell transplantation approach in development as therapy for hereditary pulmonary alveolar proteinosis (hPAP), a surfactant accumulation disorder caused by mutations in CSF2RA/B (and murine homologs). We conducted a toxicology study of PMT of Csf2ra gene-corrected macrophages (mGM-Rα+Mϕs) or saline-control intervention in Csf2raKO or wild-type (WT) mice including single ascending dose and repeat ascending dose studies evaluating safety, tolerability, pharmacokinetics, and pharmacodynamics. Lentiviral-mediated Csf2ra cDNA transfer restored GM-CSF signaling in mGM-Rα+Mϕs. Following PMT, mGM-Rα+Mϕs engrafted, remained within the lungs, and did not undergo uncontrolled proliferation or result in bronchospasm, pulmonary function abnormalities, pulmonary or systemic inflammation, anti-transgene product antibodies, or pulmonary fibrosis. Aggressive male fighting caused a similarly low rate of serious adverse events in saline- and PMT-treated mice. Transient, minor pulmonary neutrophilia and exacerbation of pre-existing hPAP-related lymphocytosis were observed 14 days after PMT of the safety margin dose but not the target dose (5,000,000 or 500,000 mGM-Rα+Mϕs, respectively) and only in Csf2raKO mice but not in WT mice. PMT reduced lung disease severity in Csf2raKO mice. Results indicate PMT of mGM-Rα+Mϕs was safe, well tolerated, and therapeutically efficacious in Csf2raKO mice, and established a no adverse effect level and 10-fold safety margin.

Long-Term Safety and Efficacy of Gene-Pulmonary Macrophage Transplantation Therapy of PAP in Csf2ra-/- Mice.

Hereditary pulmonary alveolar proteinosis (PAP) is a genetic lung disease characterized by surfactant accumulation and respiratory failure arising from disruption of GM-CSF signaling. While mutations in either CSF2RA or CSF2RB (encoding GM-CSF receptor α or ß chains, respectively) can cause PAP, α chain mutations are responsible in most patients. Pulmonary macrophage transplantation (PMT) is a promising new cell therapy in development; however, no studies have evaluated this approach for hereditary PAP (hPAP) caused by Csf2ra mutations. Here, we report on the preclinical safety, tolerability, and efficacy of lentiviral-vector (LV)-mediated Csf2ra expression in macrophages and PMT of gene-corrected macrophages (gene-PMT therapy) in Csf2ra gene-ablated (Csf2ra-/-) mice. Gene-PMT therapy resulted in a stable transgene integration and correction of GM-CSF signaling and functions in Csf2ra-/- macrophages in vitro and in vivo and resulted in engraftment and long-term persistence of gene-corrected macrophages in alveoli; restoration of pulmonary surfactant homeostasis; correction of PAP-specific cytologic, histologic, and biomarker abnormalities; and reduced inflammation associated with disease progression in untreated mice. No adverse consequences of gene-PMT therapy in Csf2ra-/- mice were observed. Results demonstrate that gene-PMT therapy of hPAP in Csf2ra-/- mice was highly efficacious, durable, safe, and well tolerated.

Targeting cholesterol homeostasis in lung diseases.

Macrophages are critical to organ structure and function in health and disease. To determine mechanisms by which granulocyte/macrophage-colony stimulating factor (GM-CSF) signaling normally maintains surfactant homeostasis and how its disruption causes pulmonary alveolar proteinosis (PAP), we evaluated lipid composition in alveolar macrophages and lung surfactant, macrophage-mediated surfactant clearance kinetics/dynamics, and cholesterol-targeted pharmacotherapy of PAP in vitro and in vivo. Without GM-CSF signaling, surfactant-exposed macrophages massively accumulated cholesterol ester-rich lipid-droplets and surfactant had an increased proportion of cholesterol. GM-CSF regulated cholesterol clearance in macrophages in constitutive, dose-dependent, and reversible fashion but did not affect phospholipid clearance. PPARγ-agonist therapy increased cholesterol clearance in macrophages and reduced disease severity in PAP mice. Results demonstrate that GM-CSF is required for cholesterol clearance in macrophages, identify reduced cholesterol clearance as the primary macrophage defect driving PAP pathogenesis, and support the feasibility of translating pioglitazone as a novel pharmacotherapy of PAP.

System change in healthcare: the Ontario Stroke Strategy.

The development of the Ontario Stroke Strategy was due to a combination of strategic decisions, hard work, good timing and luck. This article reviews the development of the strategy from its early days to the present, outlines the approaches used in working with government to influence its policy and investment decisions and reflects on the future.

Advertising strategies to increase public knowledge of the warning signs of stroke.

BACKGROUND AND PURPOSE: Public awareness of the warning signs of stroke is important. As part of an educational campaign using mass media, the Heart and Stroke Foundation of Ontario conducted public opinion polling in 4 communities to track the level of awareness of the warning signs of stroke and to determine the impact of different media strategies. METHODS: Telephone surveys were conducted among members of the general public in 1 control and 3 test communities before and after mass media campaigns. The main outcome measure used to determine effectiveness of the campaigns was the ability to name > or =2 warning signs of stroke. RESULTS: In communities exposed to television advertising, ability to name the warning signs of stroke increased significantly. There was no significant change in the community receiving print (newspaper) advertising, and the control community experienced a decrease. Television increased the knowledge of both men and women and of people with less than a secondary school education but not of those > or =65 years of age. Intermittent, low-level television advertising was as effective as continuous, high-level television advertising. CONCLUSIONS: Results of this survey can be used to guide mass media-buying strategies for public health education.