Evidence for the Occurrence of Human Erythrocyte Membrane Sialoglycoproteins in Human Kidney Endothelial Cells

Abstract

Several mouse monoclonal antibodies recognising different epitopes on human erythrocyte sialoglycoproteins α and β (syn: glycophorins A and C, respectively) react with human renal endothelium. Those monoclonal anti-blood group M and anti-blood group N antibodies which recognised the M/N epitopes on sialidase-treated human erythrocytes also reacted with human renal endothelium whilst those which recognise the M/N epitopes on native, but not on sialidase-treated human erythrocytes were not reactive with human renal endothelium. These results provide evidence for the occurrence of α and β molecules in renal endothelium and suggest that α in renal endothelium is incompletely sialylated.

Molecular and genetic analysis of disseminated neoplastic cells in lymphangioleiomyomatosis

“…Sorting of low-density cell fractions also revealed a subset of cells with LOH that were reactive with CD235a, an antibody to glycophorin A, a sialoglycoprotein present on red blood cells (19). Glycophorin A-like epitopes have been reported on other nonerythroid cells, including normal kidney endothelium, and melanoma and breast cancer cells (20,21). We found immunoreactivity to CD235a in 31% of the 29 LAM lung samples examined microscopically, suggesting that proteins present in LAM nodules may share epitopes cross-reactive with glycophorin A.…”

Other Blood Group Antigens and Antibodies

“…22,23 Expression of GPA and GPB in erythroid tissues occurs early in erythroid differentiation, but the associated antigens are detectable only later in erythroid development. GPA and GPB are expressed in renal endothelium and epithelium.…”

A major endothelial plasmalemmal sialoglycoprotein, gp60, is immunologically related to glycophorin.

“…Antisera raised against purified murine glycophorins have been shown to react strongly with erythroid cells but not with platelets, Iymphocytes, macrophages, and granulocytes (34). Other observations suggest, however, that molecules immunologically related to human glycophorins A and B (21)(22)(23)(24)(25)(26) and C (20) (38), thrombospondin (39), SPARC (40), and GMP140 (41). SPARC is an albumin-binding protein that, unlike gp60, is secreted by endothelial cells and circulates in the blood bound to albumin (40).…”

“…Based on indirect evidence, the presence ofglycophorin-like molecules in a variety of nonerythroid cells has been suggested for the glycophorins A, B, and C (20)(21)(22)(23)(24)(25)(26). In this study, we investigate possible structural similarities between endothelial sialoglycoproteins and glycophorins by using a polyclonal antiserum directed against murine glycophorins.…”