A specific Thy-1 molecular epitope expressed on rat mesangial cells.

Abstract

An experimental model of proliferative glomerulonephritis induced by antibodies against the Thy-1 antigen has been established and used to study the pathological sequence from mesangiolysis to mesangial proliferation. However, the functional role of the Thy-1 molecule distributed on rat glomerular mesangial cells remains unknown, so the present study was undertaken to determine the precise subcellular localization of Thy-1 molecules in vitro using two anti-Thy-1 monoclonal antibodies, 1-22-3 and OX-7. Immunofluorescence and immunoelectron microscopic studies in combination with laser scanning analysis showed that the localization of 1-22-3 and OX-7 bound to cultured rat mesangial cells differed, particularly when cocultured with vascular endothelial cells. An epitope recognized by 1-22-3 was concentrated specifically on the mesangial cell surfaces facing the neighboring endothelial cells. In contrast, OX-7 bound to mesangial cell surfaces and extracellular parts in a diffuse pattern independent of contact with endothelial cells. This finding is consistent with our previous ultrastructural study in which the reactivity of 1-22-3 with normal kidney tissue was limited to mesangial cell surfaces facing endothelial cells. These results led us to conclude that the specific Thy-1 molecular epitope recognized by 1-22-3 is associated with points anchoring mesangial and endothelial cells, where this anti-Thy-1 antibody binds after injection in vivo, resulting in mesangial cell detachment from the vascular capillary wall, mesangiolysis and mesangial cell dysfunction. We believe that the critical epitope detected by 1-22-3 in this study plays an important role in mesangial cell function and injury.

• Authors: T Oite, M Saito, Y Suzuki, T Arii, T Morioka, F Shimizu
• Journal: Experimental nephrology (Exp Nephrol) 1996 Nov-Dec Vol. 4 Issue 6 Pg. 350-60 ISSN: 1018-7782 [Print] Switzerland
• PMID: 9001890 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Monoclonal
• Epitopes
• Thy-1 Antigens

Topics

• Animals
• Antibodies, Monoclonal
• Cell Communication
• Cells, Cultured
• Disease Models, Animal
• Endothelium, Vascular (cytology, immunology)
• Epitopes (metabolism)
• Glomerular Mesangium (cytology, immunology)
• Glomerulonephritis, Membranoproliferative (etiology, immunology)
• Immunohistochemistry
• Microscopy, Confocal
• Microscopy, Electron
• Microscopy, Fluorescence
• Rats
• Subcellular Fractions (immunology)
• Thy-1 Antigens (metabolism)