Testing the Effectiveness of Pulmonary Macrophage Transplantation to treat Pulmonary Alveolar Proteinosis Caused by Niemann-Pick Type C

Abstract

Niemann-Pick Type C is a lysosomal storage disorder that hinders intracellular trafficking of cholesterol in cells. Poor cholesterol transport in macrophages in the lungs can significantly inhibit macrophage consumption of debris in the alveolar air sacs, interfering with respiration. This condition includes pulmonary alveolar proteinosis (PAP), and is a pathological sign of Niemann-Pick Type C. Research on methods to resolve PAP includespulmonary macrophage transplantation. Pulmonary macrophage transplantation has been successful in treating PAP resulting from other genetic disorders, but not from Niemann-Pick Type C. In order to determine how well pulmonary macrophage transplantation would treat PAP caused by Niemann-Pick Type C, the quality of cell dispersion inthe lungs must be studied. The purpose of this project is to test pulmonary macrophage transplantation on healthy mouse models to determine obstacles that might arise from the treatment. Determining procedural obstacles before testing the effect of the treatment on pulmonary disease, including PAP, caused by Niemann-Pick Type C would provide additional information on the effectiveness of the treatment. Carbonyliron was used as a marker for macrophages. Macrophages were harvested from healthy C57BL/6J mice and loaded with carbonyl iron. Attempts to transport macrophages via intranasal inhalation into the lungs of three C57BL/6J mice without Niemann-Pick Type C disease were made. These mice were euthanized at differing times after inhalation (15 minutes, 20 hours, and 72 hours). Their lungs were collected, fixed, imbedded in paraffin, and sectioned. Sections were attached to glass slides for histology. These were stained with TurnbullBlue stain and Orange G counterstain. Lungs were examined for macrophage dispersion and quantity. The results showed dispersion of macrophages across lung tissue, but only a very few cells were found. The lack of cells led to the reasoning for the hypothesis that limited cells reached the lung tissue by intranasal inhalation while a majority may have stuck to the walls of the upper respiratory tract before the lungs. This study proved that pulmonary macrophage transplantation using intranasal inhalation produced inadequate results.