|Budget Amount *help
¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1999 : ¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1998 : ¥1,900,000 (Direct Cost : ¥1,900,000)
The origin of crescent forming cells in crescentic glomerulonephritis has not been clarified in spite of the application of monoclonal antibodies (mAbs) against glomerular epithelial cells or monocytes/macrophages. This study was undertaken to characterize the cellular composition of crescent using a new marker, mAb OS-3, produced against macrophagic cells into which podocytes changed in normal rat glomerular culture. mAb OS-3 was confirmed to be reactive with some normal epithelial cells of Bowman's capsule. Three female WKY rats were injected with rabbit anti-glomerular basement membrane (GBM) serum and sacrificed, respectively at 2 hours, 1, 3, 7, 14 days and 2 months. mAb OS-3-positive cells were segmentally observed at 3 days in glomeruli, increased at 14 days, but decreased at 2 month. These mAb positive cells were corresponded to cellular crescents in serially paired light microscopy on day 3 and 14. These lacked the reactivity with anti-podocalyxin in double immunofluorescence (IF) staining. Immunoelectron microscopy of a glomerulus on day 3 and 7, however, reaction products were observed within cells, located on outer surface of GBM, which were considered to be podocyte based on its localization.
In conclusion, we have shown a possibility that damaged podocytes partly constitute crescent forming cells with phenotypic changes visualized by positive staining with mAb OS-3, proposing a novel concept of crescent formation. That is, crescent may be partly composed of phenotypically changed cells, which could not be detected by typical markers for glomerular epithelial cells or monocytes/macrophages.