Normal and neoplastic cells are protected from autologous complement (C) attack by different cell-surface C-regulatory proteins including CD59 (protectin), CD46 (membrane cofactor protein) and CD55 (decay-accelerating factor). Indirect immunofluorescence (IIF) analysis showed a differential expression of CD59, CD46, and CD55 in nine human melanoma cell lines and that the expression of CD59 was highly heterogeneous compared with that of CD46 and CD55. Levels of cell membrane CD59 were found to regulate the differential sensitivity of melanoma cells investigated to homologous C-mediated lysis; in fact, an inverse correlation (r > 0.7, p < 0.05) was found between levels of cell membrane CD59, but not of CD46 and CD55, and extent of C-mediated lysis of melanoma cells sensitized with scalar concentrations of the anti-GD3 ganglioside mAb R24. Masking of CD59 by 2.5 mu g/ml of the anti-CD5S mAb YTH53.1 induced or enhanced C-mediated lysis of melanoma cells sensitized with 2.5 mu g/ml of mAb R24; the latter phenomenon was found to be directly correlated (r = 0.865, p < 0.01) with levels of cell membrane CD59. CD59 is bound to melanoma cells by a glycosylphosphatidylinositol anchor: treatment of C-resistant melanoma cells Mel 97, by increasing doses of phosphatidylinositol-specific phospholipase C (PI-PLC), progressively decreased cell-surface expression of CD59 and increased C-mediated lysis of cells sensitized with mAb R24. Staining of 38 benign and malignant lesions of melanocytic origin by mAb YTH53.1 demonstrated that CD59 is consistently expressed in vivo and confirmed the heterogeneous expression detected in vitro. Our data, altogether, demonstrate that CD59 is the main restriction factor of C-mediated lysis of melanoma cells and that levels of CD59 may account for their differential resistance to C-mediated lysis. The analysis of the levels of CD59 could represent at; useful strategy in selecting melanoma patients who may benefit from immunotherapeutic treatment(s) that trigger C activation.

Brasoveanu, L.i., Altomonte, M., Fonsatti, E., Colizzi, F., Coral, S., Nicotra, M.r., et al. (1996). Levels of cell membrane CD59 regulate the extent of complement-mediated lysis of human melanoma cells. LABORATORY INVESTIGATION, 74(1), 33-42.

Levels of cell membrane CD59 regulate the extent of complement-mediated lysis of human melanoma cells

Maio M
1996-01-01

Abstract

Normal and neoplastic cells are protected from autologous complement (C) attack by different cell-surface C-regulatory proteins including CD59 (protectin), CD46 (membrane cofactor protein) and CD55 (decay-accelerating factor). Indirect immunofluorescence (IIF) analysis showed a differential expression of CD59, CD46, and CD55 in nine human melanoma cell lines and that the expression of CD59 was highly heterogeneous compared with that of CD46 and CD55. Levels of cell membrane CD59 were found to regulate the differential sensitivity of melanoma cells investigated to homologous C-mediated lysis; in fact, an inverse correlation (r > 0.7, p < 0.05) was found between levels of cell membrane CD59, but not of CD46 and CD55, and extent of C-mediated lysis of melanoma cells sensitized with scalar concentrations of the anti-GD3 ganglioside mAb R24. Masking of CD59 by 2.5 mu g/ml of the anti-CD5S mAb YTH53.1 induced or enhanced C-mediated lysis of melanoma cells sensitized with 2.5 mu g/ml of mAb R24; the latter phenomenon was found to be directly correlated (r = 0.865, p < 0.01) with levels of cell membrane CD59. CD59 is bound to melanoma cells by a glycosylphosphatidylinositol anchor: treatment of C-resistant melanoma cells Mel 97, by increasing doses of phosphatidylinositol-specific phospholipase C (PI-PLC), progressively decreased cell-surface expression of CD59 and increased C-mediated lysis of cells sensitized with mAb R24. Staining of 38 benign and malignant lesions of melanocytic origin by mAb YTH53.1 demonstrated that CD59 is consistently expressed in vivo and confirmed the heterogeneous expression detected in vitro. Our data, altogether, demonstrate that CD59 is the main restriction factor of C-mediated lysis of melanoma cells and that levels of CD59 may account for their differential resistance to C-mediated lysis. The analysis of the levels of CD59 could represent at; useful strategy in selecting melanoma patients who may benefit from immunotherapeutic treatment(s) that trigger C activation.
1996
Brasoveanu, L.i., Altomonte, M., Fonsatti, E., Colizzi, F., Coral, S., Nicotra, M.r., et al. (1996). Levels of cell membrane CD59 regulate the extent of complement-mediated lysis of human melanoma cells. LABORATORY INVESTIGATION, 74(1), 33-42.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/1081408
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo